The Public Safety community has come together over a most important issue: Obtaining the needed spectrum, funding, and governance structure to build and operate a nationwide, fully interoperable, broadband network to add data and video capabilities to its existing voice and slow-speed data capabilities. Today’s commercial networks offer these services but are not built to be mission-critical, which is a requirement of the Public Safety community. This paper discusses the issues and the differences between the U.S. Senate bi-partisan approach and the U.S. House of Representatives’ majority leadership approach to solving this problem.

Over the course of the past two years, the members of the Public Safety Alliance (PSA) have, time and again, met with numerous Members of Congress and their staffers in an effort to explain why this issue is so important for the first responder community and why it must be resolved before work can begin in earnest on the first fully interoperable data and video broadband network to provide mission-critical services to the Public Safety community.

Last year Senators Rockefeller and Hutchinson introduced Senate Bill 911, a bipartisan bill that would reallocate the D Block to Public Safety, provide $11billion in funding, and set up a governance non-profit corporation to manage both the construction and the operation of the nationwide broadband network while providing local control over day-to-day operations. Late in 2011, the House introduced several bills, one of which was subsequently attached to the Omnibus tax bill, which while reallocating the D Block to Public Safety missed the mark on both funding and governance and contained a spectrum give-back provision that is opposed by the Public Safety community.

As the 2011 session of Congress ended, both houses dropped the spectrum auction portions of the tax bill and a temporary tax bill was passed. As Congress starts its 2012 session, the Public Safety spectrum issue has yet to be resolved and September 2012 will mark the 11^th anniversary of the tragic events of 911 and the 7^th year since the release of the 911 Commission report that called for Public Safety communications interoperability. Congress still has not acted on this one remaining item listed by the 911 Commission as an item that needs to be addressed.

The Public Safety community has been patient and has provided all of the data and information asked of it so that those in Congress would have the information it needs to pass the legislation that is required to move the Public Safety interoperable broadband network from a goal to fruition. As we begin 2012, an election year, the Public Safety community remains solidified in its desire for the proper legislation to be passed. The issue of the reallocation of the D Block to Public Safety has now been addressed by both Houses of Congress and by both parties within both houses. However, there still remain some differences between what the Senate has proposed in S911 and what the House majority leadership is promoting. The differences are major. On the one hand the Senate bill provides for a governance organization and Federal funding that is acceptable to Public Safety while the House bill does not. Further, the House bill requires the return of 700-MHz narrowband spectrum, which is spectrum that is vitally needed and being used to provide interoperable voice services across the United States today.

The Public Safety community is strongly in favor of the terms provided in S911 with the exception of the proposed shared broadband/narrowband use of the currently allocated narrowband spectrum. It is strongly opposed to the governance, funding model, and spectrum give-back included in the most current House bill that was attached to the Omnibus Tax bill passed by the House. It is now a new year and an election year. The Public Safety community is requesting that the two Houses of Congress agree to a bill that reallocates the D Block to Public Safety, provides sufficient funding to build and operate the network, and provides for a governance organization that gives the Public Safety community a majority say in the construction and day-to-day and emergency operation of the broadband network. Moreover, the Public Safety community opposes any legislation that imposes an arbitrary give-back of spectrum based on information provided by a third party (such as an Administrator) and not directly by those involved in the operation of Public Safety networks.

If the Public Safety community is to continue to provide the services to keep America safe, to protect life and property, it needs to advance its communications systems beyond voice and it needs to provide for a nationwide data and video network as it continues to move toward interoperable voice services over its existing narrowband voice service spectrum. The idea that broadband networks can provide voice, data, and video services on a mission-critical basis is a laudable vision, but unfortunately this capability does not currently exist and has not yet been shown to even be achievable.

The Public Safety community is once again calling on Congress to act, to work out the differences between S911 and the House bills, and to reach a conclusion that is in the best interests of the Public Safety community and, therefore, the best interests of all of the citizens of the United States. The Congressional session that begins in January of 2012 should be the last session of Congress to have to address this issue and the outcome should be one that is of maximum benefit to the First Responder community as well as the citizens of the United States.

Introduction

After more than two years of effort on the part of a cohesive Public Safety community, Congress has once again failed to act on providing Public Safety with the additional broadband spectrum it desperately needs, the funding to build a nationwide network, and a governance structure that would permit the Public Safety community, which is solidified behind this effort, to be an important part of the organization that will oversee both the construction and the operation of the broadband network.

The Public Safety community is solidly behind the resolution of these issues as outlined in Senate Bill 911 introduced by Senators Rockefeller and Hutchinson that passed the Commerce Committee with a bipartisan vote of 21-4 in 2011. The House bill, including the bill that was attached as Title IV of the Omnibus spending bill H.R. 3630, is not acceptable to the Public Safety community for many reasons. First is the provision in this bill that requires the give-back of both the 12 MHz of 700-MHz spectrum now being heavily used for narrowband voice communications as well as the 2 MHz of guard bands that were designed to protect not only this spectrum but the Public Safety broadband spectrum from interference. Next is the funding model for the Public Safety broadband network that is less than half what has been proposed in S. 911 and is not sufficient to build the network. Finally, the governance proposed in the House bill that would award the governance of this network to a private firm called an “administrator” that would not be required to listen to, or take direction from, the Public Safety community or those who will be using this network.

The Spectrum Issue

The Public Safety community is appreciative of the fact that the House of Representatives has now acknowledged that the Public Safety community needs the 700-MHz D Block to be reallocated to it. However, there also appear to be some who do not understand that the broadband network is to augment the use of current Public Safety mission-critical voice communications and not to replace this capability anytime in the near future. It is the long-term goal of Public Safety to continue to work toward better voice interoperability while building out a new data and video-capable nationwide and fully-interoperable data and video network.

At some point in the future, if and when mission-critical voice capabilities become available over the Public Safety broadband network, the Public Safety community will be more than willing to sit down with members of Congress and/or the FCC to review the Public Safety spectrum allocations with the goal of returning some portions of the spectrum now used for narrowband mission-critical voice to the Federal Government. However, this cannot be accomplished until such time as all of the requirements for mission-critical voice included in the National Public Safety Telecommunications Council (NPSTC) document[1] can be met using the spectrum allocated for broadband services and equipment that will provide mission-critical voice services over the broadband network are readily available at an affordable price.

The spectrum that could then be returned to the Federal Government would have to be carefully determined and a timeline for its return developed to provide for the relocation of those Public Safety agencies now using that spectrum. The timing would have to be long-term such as to not place an additional financial burden on state and local communities. In any case, the current 700-MHz narrowband voice spectrum is today, and well into the future, playing an important role in providing interoperable mission-critical voice communications systems for states, regional, metropolitan, and other Public Safety voice communications systems. In reality, this spectrum should be the last portion of the existing Public Safety narrowband spectrum to be considered for reallocation for non-Public Safety use. It is on this spectrum that the most progress has been made toward providing the Public Safety community with interoperable mission-critical voice communications services.

This spectrum only became available to the Public Safety community in June of 2009 and already several $billion have been spent deploying systems all across the United States that are, today, providing multi-agency interoperable mission-critical voice communications. The mere fact that its “give-back” is included in the House bills has caused many agencies to halt their plans to build new networks on this spectrum until the issue has been resolved. Until the give-back of this spectrum is taken off of the table, Public Safety agencies are not willing to invest in the new, much more interoperable voice communications systems they need. The end result is that the potential give-back of this spectrum has done serious damage to the implementation and planning for hundreds of Public Safety mission-critical voice systems. Since this spectrum became available only two years ago, the Public Safety community has done more to solve the interoperability issues for mission-critical voice with this spectrum than has been done by any Federal organization. And while some of the funds have been provided by Federal grants, most of the funding has been from the local communities that are committed to providing the best possible mission-critical voice systems to their first responders. Taking this spectrum away now will set the Public Safety community back to the days when Interoperability was only a vision rather than a goal that is now being realized in many areas of the United States.

Mission-Critical Voice Over Broadband

There are apparently many people within the Federal Government who believe that mission-critical voice over wireless broadband services (LTE) is only a few short years away. This is a misconception. In reality, no one knows when or even IF LTE can and will support mission-critical voice, and at what cost. Today none of the commercial LTE network operators in the United States (AT&T, Verizon, Metro PCS, and Leap Wireless) or around the world have deployed standard non-mission-critical voice on their LTE networks. Commercial operators are still making use of their second-generation (2G) and third-generation (3G) networks for voice and most of them have no plans to shift this voice usage to their LTE networks for a number of years.

Yes, there is some experimentation with what is known as Voice over LTE (VoLTE), which is based on Voice over IP, but no network operator is ready yet to mix voice and broadband data services over LTE. It will be a number of years before they are ready to make this transition and they realize that adding voice to their LTE networks will reduce their broadband services capacity. They lived through their inability to provide enough broadband capacity on their existing 3G networks and are going to be slow to move voice to LTE because of the impact it will have on broadband capacity. For the time being, it is also less expensive to continue to use their 2G and 3G networks for voice services. The voice that will eventually be implemented over these commercial networks will NOT be mission-critical[2] in nature but rather the same type of voice services in use today on the 2G and 3G networks.

When a smartphone or other wireless device on a commercial network is out of range of that network or if the network is overcrowded as happens during major events (most recently the earthquake on the east coast followed by the hurricane), the device is useless to the customer. Likewise, if the customer is inside a building or in a basement where there is no coverage the device does not work and there are no communications at all. This may be acceptable to commercial network customers but it is NOT acceptable for the first responder community. First responders need to have communications all of the time whether they are in range of a network or not. When they are out of range of a network today they have the ability to communicate device to device, something that is not available on any commercial wireless network. This is only one, but one very important attribute of mission-critical voice communications. Another is one-to-many communications that are needed for day-to-day and emergency communications. This is not possible, today, over any commercial network except by using push-to-talk services that are not widely used and are not, in any case, mission-critical in nature.

Will it be possible to provide for full mission-critical voice communications over the Public Safety broadband network? It is hoped that it will be possible at some point in the future, but as of today there is no assurance that it will be possible or how far in the future it will be before it might become available. Therefore the idea of requiring the give-back of essential mission-critical voice spectrum in the 700-MHz band is not and will not be something that the Public Safety community or state and local government entities can support. Further, in the House version of the spectrum bill the determination of when mission-critical voice will be available over LTE would be made by a private company administrator and not by the Public Safety community—something that is totally unacceptable.

Another issue that has not been addressed by those who believe mission-critical voice over LTE is just around the corner is the fact that mixing voice and data services on the same broadband network means that some of the broadband capacity normally used for data and video services will be taken up by voice users. In major incidents, which tend to occur within confined areas that may only be covered by one, two, or three cell sectors, it is possible or even probable that mixing voice with broadband data and video will reduce the data and video capacity at a given incident enough that the data and video capacity will not be sufficient to meet the requirements of the incident.

One final note regarding the spectrum issue and the give-back of narrowband spectrum: If those within Congress and the Federal Communications Commission believe that broadband services will be able to handle voice, data, and video applications going forward, why is the FCC moving forward with its unfunded narrowbanding requirement for all land mobile radio (LMR) users between 150 and 512 MHz? This requirement with a January 1, 2013 deadline means that land mobile radio users including Public Safety are spending millions of dollars modifying existing equipment or buying new equipment in order to meet the mandate of operating wireless voice communications systems in even narrower portions of the radio spectrum. The implication is that while broadband is important for broadband services, narrowband voice systems will be in use for many years to come and therefore the FCC is requiring the narrowbanding of these land mobile radio systems in order to be able to add more voice radio channels within those portions of the spectrum affected by this order. If broadband is, indeed, the only future of wireless that is important, then why is the FCC moving forward with this unfunded mandate?

Public Safety Network Funding

Senate Bill 911 calls for designating $11 billion to be used for building the nationwide network plus $100 million per year for four years for Public Safety research and development. The amount of funding in the House bill is a minimum of $5 billion with an upside, depending on spectrum auction revenue of $1.5 billion for a total of $6.5 billion. In reality neither of these amounts is enough to build out the entire nationwide network, but the $11 billion number contained in S911 is a lot closer to what the final bill will be than the $6.5 billion contained in the House bill. Further, the money included in S911 for research and development can be used to help determine if mission-critical voice over LTE will be practical and within what timeframe. Without this funding the commercial industry would have to foot the bill for R&D and in today’s uncertain financial climate this type of research is unlikely to be a priority for any of the companies that have the knowledge and expertise to make that determination.

The funding requested in S911 is closer to the figure arrived at by the FCC[3] and is by far the most realistic of the two amounts. In recent years cities, towns, counties, and states have already expended $billions in Public Safety voice system upgrades, in narrowbanding its systems, and in deploying voice systems within the 700-MHz narrowband spectrum. In order to make this network a true nationwide and fully interoperable network to add data and video capabilities that will bring Public Safety communications into the 21^st Century they will still have to spend additional $millions if not several additional $billions more. If the amount made available from the auctions is reduced even to the $6.5billion level, the time needed to build this network will more than double and in some areas of the United States it may never be built at all.

The reality is that the funds it will take to build and operate this network need to be made available from the proceeds of the spectrum auctions and they must be sufficient to ensure that the network is built in a timely manner and provides the 96% population coverage envisioned. This funding will have no direct impact on the national debt, and once the network is built and put into operation there are provisions in S911 that the network will become self-funded through public/private partnerships moving forward. The required funds need to be viewed in the proper context. This is an investment in Public Safety and first responders’ ability to perform the tasks they face every day protecting our lives and property.

Governance

Senate Bill 911 calls for the establishment of a non-profit governance organization known as the Public Safety Broadband Corporation. The board of directors of this organization would be made up of four Federal members and eleven non-Federal members. The non-Federal members would be made up of three members that represent states, localities, tribes, and territories; three Public Safety members; and five members with specific expertise in finance, technology, and other disciplines required by the BOD.

While the Public Safety community would rather see more representation from within the Public Safety community, the organizations making up the Public Safety Alliance believe this is a workable model and will provide for meaningful Public Safety input on the construction and operation of the network. The House bill, on the other hand, calls for a private company that would become the network administrator. This administrator would have the sole responsibility of building and operating the network and would not be required to have any oversight or control from the Public Safety community—the very community that will be using this network for mission-critical data and video applications.

There are a number of issues with this approach. Public Safety would have minimal control over this administrator model and would have to go to Federal District Court to challenge any decisions made by the administrator that ran counter to the needs of the Public Safety community. It is doubtful that any of the firms that typically provide this type of administration and oversight for Federal or local government networks have the qualifications to know and understand the requirements of the Public Safety community, which are different from requirements for non-mission-critical network construction and operation.

The Public Safety community currently has an appointed administrator to oversee the 800-MHz rebanding required because of interference to Public Safety communications by Sprint/Nextel. This arrangement has proven that in many cases the needs of the Public Safety community have gone unmet and that the administrator actually slowed the process down and added $millions to the cost of the rebanding. This rebanding cost is borne by Sprint/Nextel but the cost overrun for the rebanding has added several significant costs to the final price tag for this project and has contributed to delaying completion of the process.

The Public Safety community is not in favor of the administrator approach to network construction and operations. The vision of the Public Safety community is that the proper governance organization modeled after the one contained in Senate Bill 911 is the best way to provide the governance needed as well as oversight of the network funding. This network is being built for use by the Public Safety community, and while it will be nationwide in scope, most of the day-to-day operational requirements will be met at the local level. Having a network administrator dictating how the network will be constructed and operated is not viewed with favor by the Public Safety community.

Conclusions

There is now a bipartisan consensus in both Houses of Congress, the 700-MHz broadband spectrum known as the D Block should be removed from the auction block and reallocated to the Public Safety community. The issues remaining to be settled have to do with the appropriate amount of funding, the governance of the nationwide network, and the fact that Public Safety should not be required to give back spectrum as part of the bill that ultimately passes Congress.

Public Safety is committed to working with Congress and the Federal Communications Commission to discuss spectrum give-backs in the future, after the broadband network is operational and research has been conducted on the feasibility of providing mission-critical voice over LTE. It is too early at this juncture to require that a specific portion of the Public Safety spectrum be given back, especially if that determination is to be made by a network administrator.

More than ten years after the tragic events of 911, tremendous progress has been made by the Public Safety community to provide better interoperability between agencies. It is now time for Congress to act to add mission-critical data and video capabilities to the communications tools available to the first responder community. To that end, the Public Safety community is asking that Congress come together and support a plan that is fair for Public Safety and allocates it the spectrum, funding, and governance it needs to provide these important augmented services to first responders. Enabling first responders to go anywhere and be able to exchange data and video, and letting them retain the narrowband voice spectrum they need to continue to improve voice interoperability more than ten years after 911 is still of concern to those who provide assistance to the citizens of this nation 7 days a week, 24 hours a day.

Andrew M. Seybold

The end-goal of a single network that will provide voice, data, and video services across the nation is also a goal shared by the Public Safety community. However, this is a complex issue and a number of obstacles must be overcome in working toward that goal. In the meantime, those who believe the Public Safety LTE broadband network will soon be able to provide all of these services, making the 700-MHz narrowband spectrum obsolete, need to be aware of these issues and what needs to be done to overcome them.

This requirement that is contained in the bill presently in the House would, in reality, cripple the Public Safety community and negate all of the progress that has been made toward interoperable voice communications over the past ten years. The 700-MHz narrowband spectrum, which has only been available to Public Safety since the sunset of analog TV in June of 2009, has already seen a number of local, regional, and statewide systems built and put into operation. There are also many more agencies in the planning stages of making use of this spectrum for narrowband communications in order to further the ability to achieve voice interoperability, which has been lacking in Public Safety for more than thirty years and was brought to the public’s attention during the attacks on 9/11 and the Katrina earthquake.

The assumption is that when the broadband spectrum supports  mission-critical voice, Public Safety will be able to consolidate voice and data services on the broadband spectrum. While this is certainly the goal of the Public Safety community, it is premature to assume that mission-critical voice will be available on the LTE broadband network. The decision by Congress to include the 700-MHz narrowband spectrum as a “give back” in the House bill is, I believe, based on a lack of understanding of all of the implications this would have on existing and future Public Safety voice communications. While this is a goal that is sought after by both the federal government and the Public Safety community, there are many other factors that must be taken into consideration before definitive dates can be placed on this giveback.

The definition of mission-critical voice services may not be fully understood by those involved in the decision-making process. Public Safety mission-critical voice is vastly different from voice services being offered over traditional commercial broadband networks. Verizon has stated, for example, that it is trialing voice over IP (VoLTE as it is called) and could be ready to deploy it on its LTE network starting in 2013. However, what Verizon will be offering when it is ready for commercial service is traditional voice for those who want to make and receive voice telephone calls. This type of voice service only provides one of many of the features and functions required within the Public Safety community.

Therefore it is important that those crafting legislation that includes the giveback of the 700-MHz narrowband spectrum fully and completely understand the differences between voice and mission-critical voice.

The National Public Safety Telecommunications Council (NPSTC) recently published what is becoming the standard definition for mission-critical voice not only over LTE but also over any wireless interface.[1] The Executive Summary states that the key elements for the definition of mission-critical voice include the following:

• Direct or Talk Around: This mode of communications provides public safety with the ability to communicate unit‐to‐unit when out of range of a wireless network OR when working in a confined area where direct unit‐to‐unit communications is required.

• Push‐to‐Talk (PTT): This is the standard form of public safety voice communications today ‐ the speaker pushes a button on the radio and transmits the voice message to other units. When they are done speaking they release the Push‐to‐Talk switch and return to the listen mode of operation. 

• Full Duplex Voice Systems: This form of voice communications mimics that in use today on cellular or commercial wireless networks where the networks are interconnected to the Public Switched Telephone Network (PSTN).

• Group Call: This method of voice communications provides communications from one‐to‐many members of a group and is of vital importance to the public safety community. 

• Talker Identification: This provides the ability for a user to identify who is speaking at any given time and could be equated to caller ID available on most commercial cellular systems today.

• Emergency Alerting: This indicates that a user has encountered a life‐threatening condition and requires access to the system immediately and is, therefore, given the highest level or priority. 

• Audio Quality: This is a vital ingredient for mission critical voice. The listener MUST be able to understand without repetition, and can identify the speaker, can detect stress in a speaker’s voice, and be able to hear background sounds as well without interfering with the prime voice communications. 

A Comparison of these requirements and those available on today’s 3G and 4G commercial networks is provided in the chart below:

As can be seen from the above comparison chart there are a number of key differences between commercial voice and mission-critical voice today, and the functions that are NOT a part of broadband commercial voice or cellular voice systems today are the most important aspects of mission-critical voice for Public Safety. While it is possible that these functions can be designed into the LTE broadband technology going forward, there remain several issues:

1. What is the timing for these functions to be incorporated into LTE?
• Would they have to be approved by the world standards bodies?
• Would there have to be on-off modifications to LTE for Public Safety only?
2. Would one-to-many voice communications require the addition of what is known as eMMBS or enhanced Multi-Media Broadcast Services? If eMMBS is required, it will add substantially to the cost of the Public Safety LTE Network.[3]
3. Even if LTE can be modified to provide one-to-many push-to-talk, group call, emergency alerting, and off-network or peer-to-peer communications, can the Public Safety broadband LTE network support the number of voice paths that are needed?
• See details on voice paths below.
4. Today there is no definitive design document outlining and detailing all of the Public Safety requirements for mission-critical voice. Therefore, it is not possible to know for certain if all of these requirements can, in fact, be included in the LTE technology and if they can be, how long it will take before these changes could be made and devices become available.
• Will there be non-recurring engineering costs (NRE) associated with the development of these functions? Would these costs be paid by the federal government?
5. If LTE can be modified to meet all of the requirements for mission-critical voice at some point in the future, who will pay for the following?
• The move from 700-MHz narrowband systems to the Public Safety broadband system.
• The replacement of all existing LTE broadband devices in use by Public Safety on the broadband network until the time that mission-critical voice becomes available.
• These replacement costs will run into the multiple $millions. Will these costs be included in the relocation fees that the federal government will pay out from the proceeds of the 700-MHz narrowband spectrum auction?

It should be noted that most of the Public Safety requirements for voice services have little or no value to commercial operators. Thus, unlike the existing LTE standard, changes to the standards to permit mission-critical voice over LTE will have to be incorporated into the LTE standard for the Public Safety community only, or if the standards body elects not in include off-network voice and data communications into the standard, the standard will have to be modified for the Public Safety community, which is counter to the original purpose of making use of a commercial standard to reduce device costs.

There is also the issue of the qualifications of those promoting the use of mission-critical voice over LTE. Are they engineers with a complete understanding of mission-critical voice? Do they have any firsthand experience with Public Safety mission-critical communications? Many people assume that the requirements of commercial voice and mission-critical communications are the same. However, as demonstrated above, there are a number of significant and important differences. When a cell phone is out of range of the network on which it operates or out of coverage, the device is useless to the person holding it. In the world of Public Safety that is not an option. Voice communications is and will continue to be the lifeline for our Public Safety professionals. They need to know that when they need help, they can make a simple push-to-talk voice call or push their emergency button and regardless of where they are within network coverage or outside of it, deep inside a building or simply out of range of the network, that their call for assistance will be heard and acted upon. Therefore, those who are making statements regarding voice over LTE must have a solid grounding in what the definition of mission-critical voice is and how it can be applied to the LTE technology. Unless and until all of the various forms of mission-critical voice communications can be provided by LTE, the need for narrowband spectrum and channels will remain.

There are two sets of issues that need to be considered when making a decision about when and if Public Safety narrowband spectrum can be reallocated. The first set of issues is to fully understand the requirements of the Public Safety community for mission-critical voice. The second is to look at what within the LTE technology will have to be changed, modified, or invented from scratch.

Understanding the requirements for mission-critical voice should be the first priority for anyone seeking to determine if and when voice over LTE will be able to provide all of the different types of voice services required. Again, Public Safety requirements go well beyond the simple use of voice for voice calls. It is, therefore, vitally important that those making statements about the use of mission-critical voice over LTE have a complete understanding of all of the requirements. Below is a list of suggested qualifications that should be used to determine whether those providing the information about voice over LTE are qualified to render their opinions.

1. They have read and understand the National Public Safety Telecommunications Council (NPSTC) document: Mission Critical Voice Communications Requirements for Public Safety (MCV Functional Description). This document is also being presented to ANSI to be certified as the standard definition for mission-critical voice.
2. They understand and can explain
• The use of both on and off-network voice communications.
• Why off-network voice even when within the coverage area of a network is important to Public Safety.
3. The range requirements (distance) of mission-critical off-network voice.
• How this will be accomplished when replacing traditional handheld and mobile narrowband voice devices that operate with a transmit power of from 5 to 100 Watts with LTE devices that are today transmitting at a peak power of ¼ watt.
4.  The terms one-to-one, one-to-many, talk groups.
5. How many independent voice circuits or channels are required for any incident.
• Typically during an incident, each sub-group makes use of its own voice channel so it does not interfere with the others. The Incident Commander normally communicates with each sub-group leader and has a communications path between the incident and the command or dispatch center.

To my knowledge, beyond the NPSTC definition document referenced above, no group or individual has developed a set of specifications or a requirements document that could be provided to potential vendors to obtain feedback on the feasibility of adding all of the requirements of mission-critical voice to LTE before making a determination:

1. That LTE will be able to support mission-critical voice.
2. At what point in time these functions will be available for deployment within the Public Safety LTE network.
3. When devices will be available that will provide all of the functionality required for mission-critical voice over LTE and at what cost.

It is essential that a requirements document be drafted and that input from the chip vendors, device vendors, and software vendors be sought. Statements that are not based on specific requirements are not helpful to those who must make decisions that will impact the day-to-day operation of the Public Safety community.

That brings up the issues that must be understood and for which technical solutions must be found before there can be a determination of the “if and when” of mission-critical voice over LTE. Some of these are:

1)   What are the range requirements for off-network voice communications?

• Today’s narrowband voice devices range from 5-Watt handheld radios up to and including 100-Watt mobile radios. LTE devices today have a transmit power of ¼ Watt.
• Further, narrowband voice devices make use of more efficient external antennas while today’s commercial broadband and voice devices have much less efficient internal antennas.
• What is the range of these devices for in-building communications when required?

2)    How many simultaneous on and off-network voice channels are required?

• Many cities require multiple voice channels for dispatch. Today they normally have one to three citywide channels and then divide the city into districts with each having its own dispatch channel. They need additional voice channels on a district or multiple district basis for the units responding to an incident. The FCC’s guideline for the number of vehicles that can be managed on a single radio channel state that depending on the narrowband technology, between fifty and ninety vehicles can be dispatched and managed on a single voice channel. In many cities the number of vehicles in a fleet runs into the thousands.
• In addition, each incident usually requires multiple off-network voice channels for the various types of responders. These channels are important since they enable the individual groups to work together while keeping voice traffic off the on-network voice channels.
• The number of off-network voice channels will depend on the type of incident. In a major wild land fire as many as eighty or more of these channels are pressed into service as the incident grows in scale.

3)    How the channel is changed on the voice device.

• On a typical LTE network, the network controls the channel assignment of the device. The device itself has no provisions for changing to a different channel.
• In today’s narrowband voice systems, the channel assignments are given to those arriving at an incident and they manually switch their radios to the desired channel. Further, many field devices are set up to receive not only the assigned voice channel but also to monitor several other channels by using a scanning system with priority.
• Therefore when a device is making use of off-network voice some method of channel changing must be provided. Today’s radios are usually multi-channel capable and many have several hundred voice channels pre-programmed into them for use during both local and mutual aid incidents.

4)    Transmitter power output requirements.

• Today’s handheld Public Safety devices have transmitter power output levels of 2 to 5 Watts and make use of an external antenna. Mobile devices have a transmitter power output of 20-100 Watts and also make use of an external antenna.
• Today’s LTE devices have a transmitter power output of up to ¼ Watt and make use of internal antennas that are less efficient than externally mounted antennas. Further, the power level of the transmitter is controlled by the LTE network depending on the distance from the cell site to the device.
• The requirements for off-network voice communications call for these devices to be able to communicate with each other over a distance of several miles or between devices when one user is on the street and others are located within a building including in basements and other internal areas.

5)    Audio output.

• Today’s voice devices include device-mounted or external speakers and audio output is sufficient for users to be able to hear the voice traffic on the selected channel without having to hold the device in their hand.
• Today’s LTE devices are designed for handheld use or use with a Bluetooth device. Usual operational requirements are that the users hold the device.
• Public Safety voice devices can be listened to without having to pick up the unit. Transmissions can be made by pushing the PTT switch on an external microphone or on the side of the radio. This is very different from today’s commercial devices that require one and sometimes two-handed operation. Public Safety cannot EVER be required to use a device that takes two hands to operate. In many conditions they cannot afford to have a device that has to be held in order to hear the voice traffic on the channel.

Conclusions

The Public Safety community would like nothing better than to have a single, nationwide swath of spectrum that would enable true interoperability for all of its voice, data, and video needs. However, this must be balanced with the amount of spectrum required for day-to-day operations within large metro areas and the amount of voice, data, and video traffic that will ride on the wireless network. Overloading a commercial cellular network, as has happened on numerous occasions, results in blocked or dropped calls and dropped data sessions. This is not an option within the Public Safety community.

Going forward there must be a balance of existing voice spectrum and its usage with that of the new broadband spectrum. The 700-MHz narrowband spectrum is vital in this regard. As we move forward over the next five years and the Public Safety broadband network is built out, it will provide interoperable data and voice communications services. However, to expect it in the short term to also provide fully interoperable voice communications to replace that which is presently on the Public Safety narrowband channels is not realistic.

It is hoped that someday this can be accomplished. The issue is when that day will come, what must be done, and how much money must be invested before we get there. There are many questions and few answers, thus planning the obsolescence of the Public Safety 700-MHz narrowband voice channels is both premature and unwise. Today the best solution for providing as much voice interoperability as possible lies within the 700-MHz narrowband spectrum allocation. To plan now to reclaim it will stop, dead in its tracks, all further development of 700-MHz narrowband voice systems that are of vital importance. Public Safety does not have enough narrowband spectrum to operate on a day-to-day basis. Planning to reallocate the narrowband spectrum at some future time essentially stifles all future development of 700-MHz narrowband systems. Cities, counties, and states will not invest $millions building out new networks that could be taken from them in the next five or ten years. Public Safety systems are built to last for decades, not years, and local governments are struggling to find the resources they need to provide for all of the public services they normally must provide. Even for Public Safety, a vital community function, they won’t invest in a network that will solve an interoperability problem today that will be shut down within a decade.

The optimists believe that mission-critical voice over LTE is just around the corner, the engineers and LTE system planners believe it will be at least a decade, and others are not convinced that LTE, as a broadband technology, will ever be able to replace narrowband mission-critical voice. From my perspective, we are better off revisiting this issue after a set of requirements has been vetted with the technical community and feedback has been provided by those responsible for the design and advancement of broadband technologies.

Further, it should not be up to anyone except the Public Safety community to decide if and when mission-critical voice over LTE will satisfy its requirements. Public Safety personnel are in the field every day to serve all of us, and they are in harm’s way much of that time. They have the right to expect that when they call for help on their radio that call will be heard and help will be on the way. If they cannot trust their communications systems to work all of the time, every time, we have no right to ask them to put themselves in situations that endanger their own lives.

Andrew M. Seybold

This draft report is being circulated and the entire report is below in PDF format. I have written the following document and submitted it to the committee for review.

Note: These comments are being made by Andrew M. Seybold as an individual and do not reflect the views of any Public Safety organization at this point in time.

General Comments

The vision of this report is certainly a vision that is shared by the public safety community: Having complete interoperability on a mission-critical basis nationwide. While this is a worthy goal and one that should be worked toward, this report needs to be viewed in light of a long-term vision and the road to that vision will mostly likely be measured in decades as opposed to years. There will have to be some major and fundamental changes concerning spectrum policy and allocations, there will need to be major advances in both cognitive and software-defined radios, and operational changes. It is not clear from this report that the authors truly understand the complexities of today’s public safety voice and low-speed data systems, nor the implications of adding a single slice of broadband-capable spectrum to these allocations.

Unlike the Internet where bandwidth can be added with routers and additional fiber assets when needed, the wireless spectrum is finite in nature and at present is totally occupied by many different types of communications services. Existing services that now require additional bandwidth cannot simply expand the amount of spectrum they utilize but must rely on other techniques to add capacity, such as adding sites spaced closer together. This is a time-consuming and expensive proposition. In some portions of the United States it can take as much as three years to add a single site because of zoning and permitting issues. The goals stated in this report, therefore, should be considered as goals worth working toward but on a long-term basis and decisions regarding operational considerations and network capacity should be taken completely within the context of wireless spectrum and the constraints placed on capacity growth, which are very different from those within the wired community.

This document is well intentioned but it appears as though the authors are trying to fit the intricacies’ of public safety voice, data, and video communications into a mold that was developed and is known as the Internet, which is based on the Internet Protocol (IP), rather than framing the values of an IP architecture within the constraints of the bandwidths associated with the current spectrum holdings of the public safety community. These spectrum holdings are spread out in multiple small segments of the spectrum from 30 MHz up to 800 MHz, and on narrow voice channels that are often intermingled with other narrowband voice channels for business and industrial radio services. Further, the 700-MHz broadband allocation for public safety at this point in time is only 10 MHz (5X5 MHz). Even when Congress reallocates the D Block to public safety, the new public safety broadband spectrum will only be 20 MHz (10X10 MHz). As noted in the report,[1] during incidents in confined areas this is not enough spectrum in which, today, to operate voice, video, and data.

This report recommends a number of items that are important and some things that are not practical to accomplish during routine but sizeable incidents that occur on a daily basis. For example, the use of deployables, mesh technologies, and replaceable network segments will, indeed, be valuable for incidents such as earthquakes, wild land fires, tornadoes, hurricanes, and other disasters that occur over wide areas and where emergency communications are needed for days, if not weeks. However, none of these capacity increasing capabilities are possible for most local incidents that occur on a daily basis and are of short but intense duration.

Further, unlike the wired Internet, the broadband spectrum currently assigned to public safety using the LTE technology has a spectrum re-use pattern of one-to-one, that is, each site uses all of the broadband spectrum, thus sites can and do cause interference to each other unless they are properly engineered. Even then, adding new sites requires extensive planning in order to minimize this interference and this type of network does not lend itself to ad hoc or mesh typologies that are put up and taken down. Mesh may in fact play an important role in public safety communications over time but must be viewed in the context of the interference it could generate. Using LTE, it is possible to deploy additional devices or nodes and have these nodes cause interference to the existing infrastructure, thereby actually degrading network performance.

The authors refer to the first hour of an incident as the “Golden Hour.” During this time those involved in the incident are busy managing the incident and taking action to prevent it from escalating beyond its current level. They have no interest, time, or ability to manage communications links as part of their tasks. To reiterate a statement made above, the first responders are USERS of communications technologies and do not have the time or the training to make changes to the infrastructure during incidents. The job of those involved with planning, building, and operating these networks is to make sure our first responders have all of the communications capabilities they need, when and where they need them.

The premise that is most important for first responders is that their communications links are invisible to them, they are mission-critical, taken for granted, and designed and implemented by others on their behalf and these links are expected to work wherever the incident is regardless of how many people are on the scene of the incident. Unlike the Internet, which is neither a mission-critical network nor a managed network, these wireless communications networks must be both mission-critical and managed. Management in the case of first responder communications does not mean managing the communications links but rather the traffic across those links. This is normally the purview of the dispatch center but it can also shift to the incident commander or communications emergency van at the scene. It is the job of those who manage the traffic to assign channels of operation that enable each sub-group involved in the response to be able to communicate among themselves and for the system traffic manager to be able to monitor and interact with all of this traffic be it voice, data, or video.

This report seems to expect the first responder community to become conversant in the various forms of communications needed and to be able to ask for what they need when they need it. In the Internet world that this report is based on and that is used as a comparison of the state of public safety communications, those who use the Internet have no involvement with its development or its deployment and do not have the ability to ask for and receive more bandwidth on demand. They are USERS who make use of the Internet to communicate. We must keep in mind that first responders are USERS of the voice and data networks they need and they are not trained communications engineers nor are they communicators. They are users of an infrastructure that has been designed and built to mission-critical standards for them by others who work with the first responder community every day and who are well versed in the needs of this community. Further, when this infrastructure is not available, all of the field devices are capable of one-to-one and one-to-many communications over fairly long distances and deep into buildings. This is not an attribute of either the Internet or commercial broadband networks where connectivity between devices must be managed by the network.

Further, the idea presented in this report that there should be a central “single entity in charge across the entire public safety enterprise” does not exhibit an understanding, as stated elsewhere in the report, that most incidents are local in nature or start as local in nature. Further, this statement does not take into account the fact that those who provide public safety services within a given service area have an understanding and a knowledge of their requirements, which in many cases are unique to their own environs and cannot possibly be transferred to a single entity. Having a nationwide organization to govern the overall network architecture is important going forward, but retaining local control over the day-to-day operations of the public safety community is of paramount importance.

Specific Comments

Observations and Context

1.1  Scope of Public Safety Community

This section states: “At least one commentator observed that achieving public safety is hard because the effort is fragmented across the country. No single entity is in charge across the entire public safety enterprise, and solutions are expensive. Leadership is needed and costs need to be reduced. The classic “name a Czar” solution is not likely to work, either. Frameworks for cooperation that can build on common planning, standards, technology, budgeting and practices seem to be the most productive avenues for progress.”

Are the authors calling for a nationwide public safety force or are they calling for a nationwide body to govern the use of public safety spectrum? It is difficult to tell from this paragraph. If it is the latter they should also be aware that it is the goal of the public safety community to have a nationwide broadband network that is a single license holder, and governance for the nationwide aspects of the network’s deployment and operation. Beyond that the local jurisdictions must have the ability to manage their own portion of the network. A nationwide governance organization cannot know what the local requirements are, what the local coverage requirements are, and how the local jurisdictions are managed.

My view is that it would be almost impossible to place the control and operation of the existing narrowband channels under such an organization. The local, regional, and state public safety agencies have been working diligently to make their voice systems more interoperable and many local jurisdictions are now served by regional and even statewide networks or overlay networks to provide for interoperability. Yet in each case the autonomy of the local jurisdictions remains in place, as it must, now and into the future.

Savings for all can certainly be enjoyed by combining networks and consolidating 911 and dispatch functions, but at the end of the day it is the chief of each service in any given area who is responsible for the actions and day-to-day activities of those who serve beneath him or her. It is the local feet-on-the-street first responders who understand their needs, their terrain, their population, and their problems. Trying to manage them and consolidate them into larger and less autonomous groups is not an option now or in the future. As important as technology is to these departments, local control of their resources is more important. The issues of technology advancements need to take into consideration the politics involved in the public safety community as in every other community. It is necessary to balance technology and achieve cost savings by aggregation of resources with the very real world of resource management and this must be accomplished from the ground up as opposed from the top down if it is to succeed.

1.2  Modern Communications

This section discusses the fact that voice communications is not enough in this day and age and that voice, data, and video are needed. Then it goes on to declare that the world of packet does not care what is being carried inside a packet—in other words, bits are bits. The statement goes on to say that first responders need access to the world-wide-web, which is a true statement. However, the authors do not address the fact that the world-wide-web, which is accessible only via the Internet, relies on a wired network that is neither mission-critical in design nor a managed network. It is a first come, first served network that is subject to not only local but international congestion, and today the Internet is the vehicle being used by hackers and purveyors of malware intended to cripple sites, invade even the most secure of sites, and otherwise wreak havoc with communications. Nor does this statement address the fact that within public safety voice must always have absolute priority during incidents. Data and video are great new enhancements that will assist the public safety community and provide better service for the general public but the first and last line of defense is and most likely will continue to be voice communications.

Even fighter pilots with millions of dollars worth of sophisticated data communications gear, heads-up controls, radar, and other modern day electronics ignore all of this technology when two or more of them are involved in a dog fight. Instead, voice between the pilots is how they communicate, coordinate, and survive a battle. Voice must have absolute priority over all other forms of communications, not only on-network voice but off-network as well. Perhaps in the future IP-based systems will be able to handle all of the requirements of public safety mission-critical voice but the road to the ideal will include a number of smaller steps along the way. It is ambitious and commendable to have an end goal, but voice over broadband for public safety will come in much smaller steps. It will start with non-mission-critical telephone voice and push-to-talk services. It will evolve to include IP bridges between voice over IP and existing P25 and analog networks, and it will continue to evolve over time. The ultimate goal is still in the distant future, not on the horizon.

The following is the last paragraph of this section: “Implicit in these observations is the apparent need for standards that will permit interoperation of communication devices and systems across a broad swath of actors in the public safety landscape. That these standards would benefit from international scope should be apparent, in the interest of facilitating responses to nondomestic emergencies, and taking advantage of larger markets to drive costs down through economies of scale.”

Public safety’s choice of LTE and its FCC-mandated use on the public safety broadband network were made because LTE is based on standards of an international scope. In the realm of existing narrowband voice technologies there are no international standards. Some of the world makes use of a voice technology known as Tetra while in the United States there is a standard for digital voice known as P25, a term used by the authors in other parts of this paper.

It should be noted that LTE as a standard is worldwide and many public safety agencies around the world are seeking spectrum over which to deploy the LTE standard for public safety broadband. It should also be pointed out here that even within the world of commercial LTE deployments, this technology, so far, will be used on more than 41 different portions of the spectrum in both the more common Frequency Division Duplex (FDD) version and the newer Time Division Duplex (TDD) version. Therefore it is doubtful that there will be any LTE devices capable of commercial use on a global basis, let alone within the public safety community. However, several countries including Canada are following the lead of the United States and asking for spectrum within the same band as that which will be used within the United States.

1.3  Resilience, Robustness and Recovery

This section deals primarily with the issues related to major network failures due to such things as loss of power, loss of infrastructure, and lack of operating personnel and recommends the caching of such equipment that is based, again, on standards. The authors are perhaps not aware that today there are already caches of voice-capable radios for the various services across the United States and that they can and are deployed on an as-needed basis, as was mentioned above. However, it takes time to move these caches into position and deploy them. Time is not available for short-duration incidents but these caches are certainly a valuable resource during longer-term incidents due to natural or man-made disasters. Deploying temporary broadband infrastructure when required depends upon many variables, some of which are time consuming. First is the issue of network-inflicted interference if the new infrastructure is not deployed properly and second, there is the issue of the backhaul from the temporary sites. Backhaul for broadband will require between 30 and 50 MHz of capacity from each cell site back to the network core, and this backhaul will need to be low latency connections that, in many cases, rule out the use of satellite services.

Unlike standalone voice communications equipment, the broadband network must be deployed as a network complete with several working databases and other back-end infrastructure. If a new network or network core is deployed to replace one that is out of service, it must either be connected to the nationwide network in order to be populated with the list of approved and authorized devices or such a database must be built in the field at the scene of the incident. This is a long and involved process, yet until it is completed the broadband network is totally unusable in the field. If the Internet were to lose all of its name servers, users would not be able to traverse the Internet without knowing the specific IP address of the device they want to communicate with, and this is also true within an LTE broadband network.

Authors note: During Katrina both the commercial and public safety equipment and service providers quickly shipped equipment and personnel to New Orleans. Within 48 hours of the hurricane most of the wireless communications infrastructure could have been rebuilt, portable radio batteries recharged, and some of the commercial networks placed back into service. However, those in charge of the incident would not permit the equipment or the personnel in attendance to install it into the city because they were not deemed “first responders” and therefore were excluded from the area.[2]

Having deployable caches of equipment is a critical part of public safety communications as long as there is a realization that this equipment will take time to transport and set up. If those trained in its deployment are excluded from the incident it will be of little use to those who need it when they need it.

The last paragraph in this section states: “At least one participant in the public meetings suggested the creation of self-supporting “Regional Resilience Networks” acting as emergency communications utility companies that could be interconnected, possibly through commercial backbones. Such systems in the 25 largest coastal metropolitan areas would cover approximately 100 million of the 330 million U.S. populations. In a related observation, the incorporation of private sector facilities, organizations and resources into national scale planning for public safety could lead to cost sharing and increased coherence.”

It should be noted that this idea was brought forth by “at least one participant in the public meetings” and was not consensus-driven. Using commercial backbones during an emergency has proven time and time again to be an unworkable solution for emergency communications. The public networks and their backbones become overloaded during emergencies, which is one of the reasons cited by public safety as to why it cannot successfully make use of bandwidth on commercial networks. Further, if the Internet is the method of connection, it should be pointed out again that it is not a secure network, it is not a mission-critical network, it is not a managed network, and it has no priority capabilities built into it.

1.4  Security, Authentication and Access Control

I have few comments regarding this section but the authors have previously argued for a nationwide system and here they are saying that, “Again, the need for broadly applicable standards is clear, as are distributed methods for authentication to avoid the potential clumsiness and latency of overly centralized management.” [Emphasis added]

1.5  Cost

This section deals with the costs of equipment for public safety systems. One of the reasons public safety chose to make use of the standard LTE technology was to take advantage of the cost savings because of the volumes of devices that will be built for LTE over the course of the technology’s life. However, it should be noted that the public safety allocation is in the portion of the 700-MHz spectrum known as Band 14, which is not the same as the Verizon allocation (Band 13) or the AT&T allocation (Band 17). The result is that while the basic chipsets are designed to operate across the entire 700-MHz band of spectrum, software, filters, duplexers, and other components are specific to one or two of the bands but not all three.

The ultimate goal of the public safety community is to evolve the LTE broadband network in such a way that it meets most of the goals of the report, but again the operative word here is “evolve.” The first LTE broadband devices are being designed as data modems. Some will support one or two of the commercial portions of the 700-MHz spectrum and some will also include support for both the 1900 MHz and 850-MHz commercial bands for roaming on existing 3G broadband networks. Over time, handheld devices will become available and it is hoped that these will evolve into combination LTE and P25 or narrowband voice units with dual functionality, and perhaps in the future evolve further into devices that will provide both data and voice services over the public safety LTE spectrum. It is certainly the goal of the public safety community to encourage vendors to develop products that move along this evolutionary path.

The comments in this section regarding the adapted and augmented use of commercial off-the-shelf equipment will be address in section 1.6 below.

1.6  Interoperation with Commercially Deployed Systems

Paragraph one of this section discusses the needs for the public safety network to extend beyond the capabilities of the commercial networks and the commercial evolution of LTE. One of these attributes that goes beyond the commercial standards deployed to date has to do with peer-to-peer or off-network (called simplex or tactical communications within the public safety community). If LTE is truly to become the voice, data, and video network of choice for public safety this is one of the critical needs that will have to be solved. Off-network, even when network coverage is available, is one of the most important forms of voice communications used by the public safety community.

There are a number of technical issues that must be overcome before LTE devices can provide this type of communications. Without going into the details, one of the issues concerns the very different transmit power levels between existing narrowband voice systems (5 watts to 100 watts) and LTE devices (typically ¼ of a watt). This difference in transmit power will make it extremely difficult to use LTE devices to provide one-to-one and one-to-many communications over the distances required and within the confines of buildings. In addition, today’s LTE devices are 100% dependent upon the intelligence built into the network with regard to their channel assignment. Finally, there is the issue of how many separate and distinct talk paths are needed during a given incident. Some may require only a handful of separate voice paths and some such as wild land fires may require eighty or more individual talk paths.

The last point made in this section deals with the adaptation of commercial equipment to serve emergency needs for the cost savings if nothing else. This is a good thing to aspire to but consideration has to be given to making the public safety spectrum available on commercial devices. If there are commercial devices in existence that have the capability to make use of the public safety dedicated spectrum, even if that portion of the spectrum is “locked out,” this could give rise to hackers who can and will find a way to unlock the spectrum, access it and, for fun or for malicious purposes, perhaps hack into the public safety network.

1.7  Role of 911 and Other Online Public Safety Systems

This section discusses today’s 911 system and its upgrade to Next Generation 911. There will be synergy between the use of public safety broadband services and NG-911, and the conclusions drawn in this section are worthy of inclusion in the future planning of the entire public safety ecosystem.

1.8  Frequency Allocations

The first paragraph of this section comments on the existing 700-MHz allocations for both broadband and narrowband public safety services. However, the last sentence in paragraph one states, “The use of 700 MHz spectrum for public safety applications is attractive because of its propagation and penetration characteristics.” This is accurate when weighed against the commercial use of 850, 1700, 1900, and 2100-MHz spectrum but is not a true statement when weighed against existing public safety spectrum in the 30, 150, and 450-MHz bands. Replacing existing narrowband voice systems in these three bands will require two to three times the number of radios sites and infrastructure in use today to provide for the same propagation. In reality, the 150-MHz band has become the gold standard for fire communications because of its propagation characteristics.

The balance of this section discusses the use of the public safety licensed 4.9-GHz spectrum as well as the use of the unlicensed 2.4 and 5 GHz or Wi-Fi spectrum. While there is some merit in using the licensed 4.9-GHz spectrum for public safety mission-critical applications, even though it is being used today for point-to-point camera and data services, it would be foolhardy for the public safety community to consider the use of the unlicensed and public 2.4 and 5-GHz Wi-Fi spectrum. This spectrum is already heavily used by many organizations and relying on its availability, especially within commercial buildings or even homes, would have the same result as trying to rely on commercial wide-area networks. Neither band offers any form of priority and the 2.4-GHz band is so heavily used, especially in metropolitan areas, that the range of existing commercial devices has deteriorated over the course of the past few years and indications are that this deterioration will continue.

Television white space, the latest type of unlicensed spectrum to be released for public use, is also discussed in this section. It too should not be considered as an option for any form of public safety mission-critical communications. The portion of the spectrum available for white space use varies from metro area to metro area and therefore defeats the goal of nationwide interoperability. If in order to reclaim additional spectrum in the future the FCC requires TV broadcasters to vacate additional spectrum in the 500 and 600-MHz bands, then availability of TV white space for use by anyone is in doubt. Therefore TV white space should not be considered as a long-term solution for public safety, or the public for that matter.

1.9  The Role of Wired Communication

I agree with this section’s premise that public safety may not have to build out all of the required backhaul but might be able to rely on others for some of it. This is a good concept and one that public safety has embraced. Companies such as AT&T, Verizon, Sprint, Harris, Motorola, and others have existing private broadband networks in place that if previsioned properly could in fact become part of the nationwide public safety broadband network. However, the use of the public Internet by the public safety network for any part of its backhaul requirements should be strictly forbidden.

2.0 Desirable Features of a Public Safety Network Design and System

2.1 Flexible System Architecture

The premise of this section is correct, but I take exception to the authors’ belief that, “One can also imagine the use of packet encapsulation and encryption methods to extend the reach of a secured public safety network across commercial backbones to increase the scope and resilience of the system.” Public safety simply cannot afford to trust the Internet even with the use of packet encapsulation and encryption. The Internet is not a secure network, it is not a managed network, and it has no provisions for priority access or priority traffic routing. Further, it is a worldwide network and millions of users have access to it including those who would bring harm to the United States.

2.1.1 Use of Internet Protocols

This section deals with the Internet and IP and suggests that IP is the solution to all communications issues, thus all public safety traffic should become IP-based so it can be transported in more ways in a more efficient manner.

These statements are all true and correct, but unmentioned is that packets rely on broadband capacity, especially when the packets are carrying video traffic, and that mission-critical voice requires absolute priority all of the time. The vast majority of the public safety narrowband spectrum is in eight different portions of the spectrum. In the spectrum below 512 MHz (for public safety that includes 150, 220, 450, and 470-512 MHz) each voice channel must be converted from a 25-KHz channel to two 12.5-KHz channels by January 1, 2013, and sometime in the future to 6.25-KHz channels. In a world that is enamored with broadband, public safety and other Land Mobile Radio (LMR) customers are being required to reduce the bandwidth of their voice channels. Add to this the fact that these channels are intermingled with channels used by business and industrial LMR systems and you can see that it is not practical, today, to replace these systems with broadband systems. There simply is not enough available spectrum for the public safety community.

The authors clearly show their bias for the Internet and the IP protocol in this section. While it is agreed that IP is the future of communications, there are a number of issues that need to be resolved before public safety can reliably and economically convert its existing narrowband voice systems to IP-based, packet-only systems. As an ultimate goal this is on target, but this paper does not address how a transition from today’s technology to an all-IP system could be accomplished, what the cost of doing so would be, or how the transition could be made in an orderly fashion.

2.1.2 Backward Compatibility

It is unclear exactly what the authors’ point is in this section except to discuss the use of multiple radios within a single device. This type of development is already underway and voice products are available.  Multiple radios in commercial devices are commonplace today. The issue not discussed is how to transition from today’s multi-band environment to an all-IP future vision.

2.1.3 Mesh or Mobile Ad Hoc Networking

This section discusses the use of mesh networks. There is value in making use of mesh networks as extensions of other networks or as standalone networks. Mesh technologies, balanced with the potential of interference, should certainly be part of the long-term vision of the public safety broadband network.

2.1.4 Robustness and Recovery

This section is basically a restatement of section 1.3 and the same comments for that section apply to this one.

2.2 Security and Authentication (entire Section)

A restatement of the issues raised in section 1.4, again the same comments apply to this section.

2.3 Standards Applications and/or Development

I agree with the statements in this section and various organizations within the public safety community have recognized the need for the use of common APIs and the vetting of applications from the development community, both within and outside of the public safety community. However, there is the question of the type of back-end infrastructure that will be employed within the public safety broadband network. If the entire system is based on an IMS core technology then SIP-based applications, including push-to-talk, will be viable on a fully interoperable basis. However, if some of the local or regional networks are deployed without IMS in the core, in order to save money, there will be compatibility issues across the network. SIP-based applications require IMS in the core to function properly.

2.4 Ruggedization

I concur with the comments in this section.

2.5 Sensor and Location Systems

For the most part I concur with this section. However, I question the use of commercial Wi-Fi as a method of in-building location. There is research underway today that could provide a more robust solution than relying on unlicensed spectrum devices for in-building location.

Further, while the use of sensors will be very helpful within the public safety community, care needs to be taken and if these sensors need to “talk to” the network then perhaps an aggregation of sensors within a location with a common connection to the network should be explored.

2.6 High Density Radio Operation

It is well known within the public safety community that incidents usually occur within confined areas and that the number of first responders can place a capacity burden on any communications network in use within this confined area. This is one reason off-network voice communications is so important in public safety. Moving off the network, even when within the range of the network, provides relief for the main network while permitting those on the scene to communicate as needed. In this case, multiple voice paths and/or data paths for peer-to-peer communications will be necessary.

No matter how robust networks are or how much spectrum is available to them, there will remain a need for off-network communications for precisely that reason. As the incident grows in size, the need for additional off-network channels for voice will also grow. Data services should also be able to operate off-network in the same manner. However, congestion must be managed. Congestion on a voice network is managed by the person assigned to the incident as the incident commander; in the case of off-network communications it is handled by the head of the group on that channel. It is unclear how off-network data capacity issues will be handled in the future and they should be taken into consideration during the long-term planning stages.

2.7 Next Generation 911 Emergency Services IP Networks

This section states the fact that both NG-911 and the public safety broadband network are based on broadband technologies and that there are probably some (or many) synergies developing between these two. I agree with these statements.

3.0 Prototyping, Collaboration and Testing

It is the view of the authors in this section that test beds must be employed in order to prove concepts and operational requirements and that the public safety community must be privy to these test beds and be able to provide their input. I concur, though some of the examples cited are from the military, which so far has been unwilling to share its findings and its research with members of the public safety community. I would assert that much of the work done for the benefit of the military has a direct correlation to public safety and that closer cooperation between the two groups would prove to be of great value.

4.0 Multiple Stakeholders

This section of the report acknowledges that there are many different public safety-related stakeholders and this is a correct statement. It goes further to point out that funding cycles are different and that many of the decisions made regarding communications do not take into account the need for interoperability. I would contend that now, more than ever, interoperability provisions are being included in system designs around the nation. Even so, more needs to be done. The key issue here is funding and its availability to provide the basis for more interoperable systems.

5.0 Programmatic Considerations

5.1 Public Safety Network Interoperability Panel (PSIP)

This section recommends that a PSIP be established to promote better public safety interoperability. It does not address the issue that interoperability is made more difficult because existing voice systems are spread out over eight different portions of the spectrum. For example, typically, in California the highway patrol operates in the 30-MHz portion of the spectrum while most fire agencies operate in the 150-MHz spectrum. Fire, police, and EMS are also assigned spectrum in the 450-MHz band, 700-MHz narrowband, and 800-MHz narrowband spectrum.

While a PSIP could probably help solve some of the interoperability issues, public safety has taken its own steps to rectify the situation. The use of 700-MHz narrowband networks as overlays for use by all agencies has been successful where they have been deployed, but again, funding these networks is a major issue. The idea that a panel of experts can solve problems created over thirty years of diverse frequency assignments is not a practical solution to the problem. There are others that are more viable, including additional funding for 700-MHz overlay systems. While these systems are not ideal, they are better than what is in place today.

5.2 Coordinated Research, Development and Testing

I agree that coordinated research and development and testing are required as we move forward. However, not one of the agencies mentioned in this section is qualified or has the knowledge of what the public safety community really needs to be able to perform its tasks. So far these test beds have been long on spending funds and short on accepting input from those who will benefit from the technologies.

In addition, between and among the agencies mentioned there are ongoing turf wars that impede progress and the desire to understand the requirements of the public safety community. One lesson that should have been learned by the Federal Government is that there needs to be input from those being served by these agencies. Instead they seem to be intent on building their own empires and moving forward to obtain funding which, frankly, could be better used by the public safety community.

Further, some of the tasks identified in the report should be the purview of the public safety community and NOT various organizations within the Federal Government. I would like to ask how many of those involved in this research have ridden along with police and fire units on a Friday or Saturday night. Perhaps I should also ask that of the authors of this report. Until those involved have a real understanding of the day-to-day issues that need to be resolved, they cannot, even with all of the testing in the world or all of the money in the world, be successful in developing standards that will provide the type of communications services needed by the public safety community.

The public safety community goes in harm’s way every day. The most dreaded call that can be given to a police officer working a beat is a domestic violence call. Why? If you have never been in the field or talked to those in the trenches you won’t understand why that is the case but it is true. Public safety communications is not about the nation. Yes, we need to be able to move people and equipment anywhere in this nation at a moment’s notice and have the communications systems work. On a daily basis it is about the cop, the firefighter, or the EMS paramedic who needs help and needs it right away. That is who we should be addressing in our plans for this next generation of networks, not a group of theorists who suddenly embrace IP and the wonders of the Internet.

5.3 National Incident Management System (NIMS)

I am in full agreement with the statements made by the authors in this section.

5.4 Training and Evaluation Program

Training must happen on a local level. Yes, there should be input from the nationwide network organization but different levels of training are needed in different areas. One size fits all training will not be sufficient in this case.

Repeating my comment regarding the network and public safety communications in general, the USERS of these communications networks are public safety professionals. Communications is one tool they have at their disposal. They do not need to be, and should not be required to be, experts in communications technology. The most important thing to remember is that the MOST IMPORTANT type of communications begins with the emergency button on the radio. If that button is pushed, the request for help MUST be heard and must be acted upon.

6.0 Conclusions and Recommendations

For this final section of the report my comments are below each of the recommendations.

1. A Public Safety Capability organization should be selected or created to orchestrate the detailed design, development and coordinated operation of a new, national public safety communication system. It should include a Public Safety Interoperability Panel and resource management capability.

A “new” network? Public safety has legacy voice systems that will be in operation for many years. 10 MHz or even 20 MHz of LTE spectrum is not sufficient to provide all of the voice, data, and video services required by public safety.

It would be better to involve the public safety community in the EVOLUTION of its existing systems into the future than to try to design a “new” communications system. It is not possible to build such a network and simply declare that on a certain date everyone will suddenly move over to the new network. Even the Internet evolved over many years into its present form and it is still evolving.

2. The architecture of the new public safety network should:

a. Incorporate commercial technology where appropriate.

Agree at least for the broadband portion of the network.

b. Extend commercial technology to achieve robustness.

Agreed except that traffic on the commercial networks should be relegated to non-mission-critical traffic along the lines of administrative or logistical support of an incident. Mission-critical traffic should never be routed over a commercial network.

c. Provide for backward compatibility or interoperability through standards adoption and/or development where feasible. Including interoperation with existing and new 911 systems.

Within reason, broadband and the Internet and IP is not always the best technology available for voice traffic, at least in the near future. Technologies can be intermingled to provide the best of all worlds for the first responder community, but the most important criteria is that it works every time regardless of where they are.

d. Give high priority to cost-effectiveness and affordability.

Agreed but NOT to the point of short-changing the requirements of the public safety community.

e. Take advantage of Internet and other packet-based technologies to support multi-media communication and mobile ad hoc network formation.

Agreed that IP is the future of SOME communications systems but not all, and with the caveat that NO public safety mission-critical communications ever use the public Internet for transport.

f. Incorporate assigned public safety spectrum and other data communication spectrum assignments and include opportunity for sharing where feasible.

Because the spectrum below 512 MHz assigned to public safety is intermingled with other Land Mobile Radio users this is neither always practical nor achievable. Sharing of public safety spectrum with others is not a good idea. Would the Secret Service be willing or should they share the spectrum they use to coordinate the protection of the President and other Government officials? Public safety needs dedicated spectrum; they never know when the next incident will occur or the magnitude of the incident. Perhaps they should be able to share spectrum in use by others on a non-mission critical basis but they should NEVER be required to share their spectrum even when not in use with others unless public safety has full pre-emptive authority to override non-public safety users.

g. Incorporate strong, federated authentication and other security technology to positively identify and authorize personnel and equipment permitted in the system.

Agreed, this is important for the public safety community.

h. Incorporate advanced position location capabilities, including indoor and underground location.

Agreed but NOT by making use of unlicensed consumer-grade Wi-Fi or other types of networks.

Conclusions

I attended and participated in the session conducted by the authors of this report in Philadelphia in August of 2011. It was obvious to me and others who attended that those leading the session were Internet and IP-centric and were not conversant in the intricacies of public safety communications. During this session we tried to convey the points that there are differences in spectrum assignments, that mission-critical voice is a necessity, and that off-network or peer-to-peer and peer-to-many peer communications is vital within the public safety community.

This report is a reflection that we failed to convince the authors that:

1. Public safety had already embraced a commercial technology in the form of LTE.
2. That network capacity is and will remain an issue.
3. That mission-critical communications requires a different set of criteria than the Internet, which is not a mission-critical network.
4. That IP is the future for all broadband communications, but narrowband communications is and will remain needed for a long time.
5. That the public safety community is willing to adopt new technologies and move into the 22^nd century but cannot sacrifice the attributes that are critical to its success and safety.
6. That a grounded understanding of the requirements of public safety is vital to the success of any new technology deployment.

It is difficult for those who created the Internet and grew up with its influence to understand that there are several types of communications with needs that cannot be met simply by embracing the premise that the Internet and IP-based packet systems can solve everyone’s needs all of the time.

I would like to recommend to the authors of this report that if they are to change the way public safety communications are implemented today for the better, that they immerse themselves in the day-to-day operations of the first responder community. They should ride along with a metro police agency on multiple Friday and Saturday nights. They should also ride along with a fire unit responding to countless EMS and fire calls, and with paramedics who are often rerouted from one incident to another deemed more life threatening.

It is not possible to understand the unique and complex nature of public safety communications in any other way. You cannot simply host a number of meetings nor can you simply listen to a few first responders. You have to live it in real time. You will come to understand that in many instances the radios first responders wear on their belts are their only lifeline to safety.

I have provided my comments and narratives in the hopes of assisting the authors in moving forward. Public safety communications is not about P25, it is not about IP or the Internet, and it is not about today versus tomorrow. It is about a lifeline between those who go in harm’s way every day and those who can ensure they remain safe and who support them in their efforts.

Andrew M. Seybold

Now Public Safety wants the D Block reallocated to Public Safety control and is perfectly willing to work with private partners in order to build out the network. These partnerships will be different from the ones envisioned by the FCC as they will most likely be regional in nature but they will accomplish the same thing in different ways. The result will be the same for the commercial partners but it will be far better for Public Safety, which will actually control the network and the assignment of priority access.

Different Types of Partnerships

It has always been the vision of the Public Safety Community to work with commercial wireless network operators to provide off-loading of non-emergency traffic onto commercial networks when needed, and to further work with commercial network operators with cell site sharing and even network backhaul and perhaps back-end services sharing. All of this is possible once the D Block has been reassigned to Public Safety and the nationwide (as opposed to national) governance organization is in place.

In the meantime, other partnerships are being formed between Public Safety vendors and commercial network operators and between Public Safety land mobile radio vendors and broadband infrastructure companies. The first of these vendor/network partnerships to be announced was between Motorola Solutions and Verizon Wireless. It is a non-exclusive agreement for the two companies to work together to provide better interoperability between Public Safety and commercial networks. Under this arrangement, Motorola provides network infrastructure and devices, and Verizon serves as a roaming partner when a user leaves the Public Safety network RF footprint, and cell site and back-haul partner for Public Safety.

More recently, AT&T and Harris formed a non-exclusive partnership that will provide a closer relationship between these two companies while better serving their Public Safety customers. This alliance is different from the Motorola-Verizon partnership as AT&T is taking the lead in LTE network build-out, leveraging its commercial LTE domain vendors in the construction of dedicated Public Safety networks that would be provided as a managed service. Unfortunately, some who read the press release announcing this partnership read it as a statement from AT&T Wireless that it considers its existing commercial network as being mission-critical. When I heard these comments from a few concerned Public Safety officials I contacted AT&T and asked about this partnership and, more specially, if it considers its network to be mission-critical. The answer was no, AT&T does not believe that its commercial network is mission-critical as defined by the needs of the Public Safety Community but that its new partner, Harris, did build mission-critical Public Safety land mobile radio equipment and that together their vision is to enable Public Safety customers to easily move from the Public Safety mission-critical broadband network to the AT&T broadband network(s).

Sometimes those who write press releases and those who try to explain what the release should convey to the world are not talking the same language. I have worked side-by-side with both AT&T and Verizon Wireless in the effort to have Congress reallocate the D Block and both of these providers have made it clear that while their wireless networks are as robust as they can possibly be in order to serve their commercial and consumer clients, neither provider believes that its network is up to the standards required by the Public Safety Community. They understand the differences and are offering their networks for use while the Public Safety broadband network is being built and after it has been deployed but ONLY to off-load non-essential, lower priority traffic in order to relieve potential congestion on the Public Safety broadband network.

Neither network provider offers Public Safety pre-emptive priority access to their commercial networks. In truth, no network operator would want to displace its own customers in favor of Public Safety during emergency incidents. There is always the possibility that the person whose call is terminated is trying to call 911 to report another emergency. It is unfortunate that the AT&T press release left a doubt in anyone’s mind that AT&T knows the capabilities and the limitations of its network (as do the other operators) when it comes to providing Public Safety voice and broadband services.

At the same time, the commercial network operators can work closely with their Public Safety equipment vendor partners to help make the move from the Public Safety network to the commercial network and back as seamless as possible. They can also assist the Public Safety vendors with a better understanding of the world of broadband wireless. While both worlds are basically the same, they are also very different. For years, the Public Safety Community has relied on voice-only systems that provide many voice capabilities that cannot be provided by commercial network operators, and the commercial network operators have, for a number of years, been providing business and consumer customers with wireless broadband access that has never before been available to the Public Safety Community.

During the past 2+ years that Public Safety has been trying to gain control of the 700-MHz D Block by asking Congress to reallocate it to Public Safety, several commercial broadband network operators, namely AT&T and Verizon, have helped educate both the Public Safety Community and the Public Safety vendors about the differences between land mobile radio voice and wireless broadband services. While both use the radio spectrum, they are based on different technologies. Simply because a person is conversant with one does not mean he/she will also be conversant in the other. Even the technical language used within each of these wireless communities is different, and it is always interesting to me to watch a commercial network engineer and a Public Safety communications engineer try to talk about wireless and fully understand what the other is saying.

Partnerships in General

The Public Safety Community has always been self-sufficient to a point. However, partnerships with federal government agencies, vendors, and those who assist Public Safety in its day-to-day activities and during emergencies (utility companies and even towing companies) have been important partners for Public Safety. Now that broadband for Public Safety is upon us, these partnerships are broadening. Commercial broadband operators, new vendors, existing vendors, private rural telcos, rural power companies and others are working together with the Public Safety Community to help make their jobs easier and safer, and to provide an even better level of service to those they serve.

Recently at the IACP conference in Chicago, I saw a demonstration of some great applications for the Public Safety Community. One was to help identify missing and exploited children, and another was to create a database of gang-related tattoos. The software vendor that is developing these applications is the FBI, and it is doing so for the good of the entire Public Safety Community.

Going forward, many different types of partnerships will be needed and welcomed by the Public Safety Community. Those who fight terrorism and crime, put out our fires, and treat and save our relatives when they are sick or injured need all of the support they can get through partnerships: Broadband is different from land mobile radio services. I applaud all of the organizations and companies that are forming such partnerships. They are doing so to increase their own business but they are also doing so because they know there are major differences between LMR and LTE and they are partnering with those who can help deliver both sets of services to the Public Safety Community. This is as it should be.

Andrew M. Seybold

The D Block, (758-763 MHz and 788-793 MHz) is the 10 MHz of spectrum (5MHz X 5 MHz) that sits next to the Public Safety 10 MHz of spectrum (5 MHz X 5 MHz) presently licensed to the Public Safety Spectrum Trust on a nationwide basis. On the other side of the D Block is a guard band that is 1 MHz wide. This guard band is licensed for itinerant use and was included in the 700-MHz band plan in order to provide a buffer zone between the C Block (licensed to Verizon Wireless on a nationwide basis) and the Public Safety spectrum.

The question before Congress at the moment is what the value of this 10 MHz of spectrum is to various stakeholders. In reality, this translates to what is the highest and best use to which this spectrum can be put and who will benefit from this decision. There are presently two options on the table for the D Block:

1. Auction the spectrum and apply the proceeds to reduce the national debt.
   a) Although the current law requires the money to be deposited directly into the U.S. Treasury. If it is to be used for deficit reduction a revision in the law will be required.
2. Auction the spectrum and use the proceeds to help build out the Public Safety network on its existing 10 MHz of spectrum.
   a) This too would require a change in the current law.
3. Reallocate this spectrum to Public Safety so it has 20 MHz of contiguous spectrum available on a nationwide basis.
   a) This also requires a change to existing law and is part of the current S 911 bill waiting to reach the floor of the Senate for a vote.

Those who favor auctioning the D Block point to the fact that this spectrum, at auction, is expected to generate between $2.6 and $3 billion in revenue for the Federal Government. (The Congressional Budget Office set the price for the D Block at $2.75 billion in its scoring of Senate bill 911.[1])  They also believe that auctioning this spectrum will create another broadband competitor in the 700-MHz band, most of which (but not all) is licensed to AT&T and Verizon Wireless.

Those who favor the reallocation of the D Block to Public Safety point to a number of reasons this should happen:

• The existing 10 MHz of spectrum is not sufficient to provide first responders with the broadband capabilities they need on a daily basis.
• The D Block is contiguous to the existing Public Safety spectrum and the cost of adding this additional spectrum to the Public Safety spectrum would be minimal whereas adding additional spectrum in the future in a different portion of the spectrum would be very costly.
• If Public Safety is, ultimately, to move voice onto the broadband spectrum and give back some of its existing narrowband spectrum, the additional bandwidth provided by the D Block will be needed on a daily basis. Without it, it will not be possible to migrate mission-critical voice to the broadband network.
• It is an investment in Public Safety communications and will provide the first fully interoperable nationwide broadband network for Public Safety communications.

This paper looks at both sides of this equation and sets the true value of the D Block if it is auctioned in order to provide a clear picture of the two choices presently under consideration. It is important that those in a position to make this decision have all of the facts on both sides of the debate available in order to be able to make the correct decision moving forward. On the one hand is the extreme need to reduce our national debt and on the other hand is the issue of providing the first responder community with all of the tools it needs to protect the citizens of this nation and itself.

Realities of Spectrum and Broadband

Before attempting to place a monetary value on the D Block, it is important to understand exactly how much of this spectrum is really available for use by the winning bidder(s), the capacity of that spectrum, the implications of building out a commercial network, and the cost of doing so. It is also important to look back at the previous 700-MHz auction in which the D Block was first offered as part of a public partnership with Public Safety and the reasons it failed to attract any serious bidders.

When deploying broadband for either commercial or Public Safety use, the broadband radio signals cannot be deployed to occupy the entire portion of the allocated spectrum. Broadband networks have to be designed so there is some unused spectrum on either side of a broadband carrier in order to protect the spectrum user in the adjacent portions of the spectrum. This is the same premise that was used when first deploying TV stations across the nation. There could not be two TV stations using channels adjacent to each other in a given area since they would interfere with each other and the TV sets would not be able to receive either signal without interference.

Knowing this, when the FCC first defined the various blocks within the 700-MHz band it did so in a logical fashion making each block—with the exception of the D Block and the Public Safety spectrum—large enough so each block that was carved out for auction was wider than the broadband signal that would be used in that portion of the spectrum. Therefore, the Lower A and B Blocks are each 6 MHz X 6 MHz or 12 MHz, and the Upper C Block is 11 MHz X 11 MHz or 22 MHz wide. This permits a network operator to deploy a 5 MHz X 5 MHz broadband system within each Lower A and B Block and a 10-MHZ system within the Upper C Block and still provide their own buffer zones of ½ MHz on either side of their block of spectrum.

However, the D Block and the Public Safety spectrum were each allocated 5 MHz X 5 MHz or 10 MHz total of spectrum because it was envisioned that the system built on these two portions of the spectrum would be a combined public/private system and therefore the FCC inserted two 1 MHz X 1 MHz bands between the C Block and the D Block on one side and between the Public Safety Block and the D Block on the other side. This spectrum was sold at auction and is to be used for itinerant communications systems across the United States, which would have made it easier for the entire 20 MHz of spectrum to be available for broadband services. However, if the two networks are separate, that is a commercial network on the D Block and the Public Safety network on the existing Public Safety allocation, then both networks will have to reduce the size of their broadband signals in order to provide for their own guard band between the two systems just as commercial network operators have had to do.

The chart below depicts the 700-MHz spectrum blocks and the amount of usable spectrum within each one:

Existing 700-MHz Band Spectrum Blocks

Note: D Block and Public Safety maximum data capacity is calculated at 20% reduction over 5 MHz X 5 MHz spectrum numbers. 

If the D Block and the Public Safety allocation are combined, the total available spectrum and the capacity available on a per cell sector basis is as follows:

Combined D Block and Public Safety Spectrum

Note: Because the A1 and GB1 spectrum guard bands are already in place the full 20 MHz of spectrum could be available for Public Safety broadband communications.

Impact on Spectrum Value

Because the D Block did not receive a qualifying bid it was not awarded to any operator and the concept of a public/private partnership did not come to realization. This leaves us with two 10 MHz (5 MHz X 5 MHz) portions of the 700-MHz spectrum directly adjacent to each other. This means that if this spectrum continues to be divided into two separate allocations, one for commercial use and one for Public Safety, the amount of spectrum available for use on each of these segments will NOT be 10 MHz but will be only 8 MHz (4 MHz X 4 MHz instead of 5 MHz X 5 MHz), which means that the available spectrum for both the D Block and Public Safety will be reduced by 20% from what should have been available.

This 20% reduction will do a number of things to both the value and usability of this spectrum:

• It will reduce the value of the D Block by at least 20% if not more.
• In order to regain the lost capacity, both networks will be required to build out many additional cell sites (20% or more).
• The overall cost of a network on the D Block will be higher than a similar network built on the A and B Blocks (6 MHz X 6 MHz). Therefore, the price any commercial entity would be willing to pay will be substantially less.

If we compare a 20% reduction in spectrum value with the expected revenue of $2.8-$3 billion, then the D Block is now worth no more than $2.24-$2.4 billion at auction. In reality, since additional cell sites and infrastructure costs will be incurred by the successful D Block bidder(s), and this cost will be substantial, the probability is that the D Block, if auctioned as a standalone portion of spectrum, will be won for less than $2 billion. Meanwhile, because Public Safety will not be able to use all of the 10 MHz already allocated to it and will also have to reduce the broadband bandwidth to 4 MHz X 4 MHz, the cost of the Public Safety network will increase by at least 20% if not more AND with only 8 MHz of spectrum available for data, the ability to employ this spectrum for video services during routine incidents will be greatly diminished as well. Further, with only 8 MHz of spectrum available on a nationwide basis, it will not be possible to migrate mission-critical voice to this network while still retaining the ability to use it for broadband services.

The results of auctioning the D Block and reducing the overall available bandwidth in the Public Safety portion of the spectrum will have additional implications both for the commercial and Public Safety side. On the commercial side, the overall network, even with additional cell sites being added to make up for the capacity, will not have sufficient capacity to provide commercial broadband services to the number of customers needed to provide a decent return on investment (ROI) for the commercial network operator. Those that would be interested in bidding on the D Block will factor this into their calculations of the value of the D Block if it is offered for auction.

On the Public Safety side, the additional costs will be significant. Today, the FCC and others have stated that in order to provide Public Safety broadband communications to 96% of the U.S. population, between 41,000 and 44,000 cell sites[2] will be needed. If the D Block is not available to Public Safety then the number of sites—each of which adds several hundred thousand dollars in capital costs as well as additional network operation costs—will have to grow to between 49,200 and 52,800 sites. This will result in a network that will cost taxpayers more, take longer to construct, and will still not provide the Public Safety community with enough broadband spectrum for its day-to-day needs[3] or to be able to be used for both mission-critical voice and data. The result is that any spectrum that might have been made available by migrating the Public Safety community to broadband for mission-critical voice will still be required by Public Safety. Therefore, any auction income from this spectrum will not be available. It is conceivable that the revenue lost to the Federal Government would be two or three times the value of the D Block auction price.

It should also be noted that the cost to build out either a 10 MHz or 20-MHz Public Safety nationwide broadband network are identical. However, the cost to build out a 10-MHz Public Safety network and then, within a few years, augment it with additional spectrum in another portion of the spectrum will double the total cost of the Public Safety network AND will require all Public Safety entities to discard their broadband devices and acquire new broadband devices that will cover both portions of the spectrum.

Conclusions

There is a perception among some within the Federal Government that the benefits of auctioning the D Block make this an obvious choice. However, the reality is that putting the D Block up for auction will, within a few years, have the following results:

• Cause the costs to build and maintain the Public Safety network to climb by at least 20% if not more.
• Cost the auction winner(s) more to build out their own networks making it more difficult for them to be competitive in the commercial market.
• Provide less capacity for both a commercial operator and for Public Safety than on other portions of the 700-MHz band.
• Would not meet the needs of either a commercial network operator or the Public Safety community in terms of broadband capacity.
• Would preclude Public Safety from migrating mission-critical voice to the broadband network when it becomes available, which in turn will result in none of the existing Public Safety spectrum being available to be reclaimed for future broadband expansion of commercial services.
• Cost taxpayers much more when in a few years Public Safety must return to the FCC and ask for even more spectrum allocations in order to provide the types of services it needs to function on a day-to-day basis.

It has been demonstrated that even the broadband capacity provided by a full 10 MHz of spectrum (5 MHz X 5 MHz) is insufficient for day-to-day Public Safety broadband communications.[4] Reducing the available network capacity by 20% as detailed above will only acerbate the issues surrounding the lack of capacity. As has been shown many times, the idea of having priority access to the commercial networks is unworkable and not reliable.[5] Therefore, Public Safety must have sufficient broadband capacity available to it on a daily basis. The use of broadband for video, data, and at some point in time mission-critical voice[6] demands that Public Safety have sufficient broadband capacity available and under its control.

The idea of auctioning the D Block, which is directly adjacent to the Public Safety broadband spectrum, might seem attractive to some in the short term, but in the long term the financial implications are that it will cost much more, over time, in taxpayer funding to build a second network for Public Safety broadband use because the spectrum presently allocated is not sufficient. Commercial broadband demand is growing exponentially and once the Public Safety network is in place this same type of increased demand for broadband services will occur within the Public Safety community as well.

The Congressional Budget Office has provided its estimate of the amount of money from auctions for the spectrum identified by the FCC. Its estimate is that it will generate $24 billion[7] in revenue and after incentive payments to TV license holders, and deducting the cost of the Public Safety broadband network, the net funds available to reduce the deficit will only be in the $6 billion range. (It should be noted here that the CBO also projected revenue from Auction 73, the 700-MHz spectrum auction, to be about $10 billion and the actual amount raised was more than $19 billion.) However, based on the last two spectrum auctions, the AWS-1 and 700-MHz spectrum auctions, industry estimates put the total value of the spectrum already identified, without the D Block, at between $40 and $54 billion. Using the same costs for incentive payments and funding the Public Safety broadband network, these numbers will yield between $20 and $30 billion for deficit reduction purposes.

Therefore, the perception that auctioning the D Block is the right way to proceed is contradicted by the realities outlined above. The true benefit to the United States as far as economic growth, job growth, and providing Public Safety with the advanced broadband tools it so badly needs to do its job and protect all of the citizens of the United States lies in the reallocation of the D Block to Public Safety and for the Federal Government to fund some of the cost of building the nationwide network from funds that will be realized from the upcoming auctions of spectrum already identified by the FCC. It should also be pointed out that in the FCC’s broadband plan[8] it has stated that it will find and make available a total of 500 MHz of additional spectrum over the next ten years. Therefore, these first auctions will be followed by others that will result in more money with which to continue to reduce the national debt.

Reallocating the D Block is logical, it meets the highest and best use criteria for spectrum allocations, and for the first time it results in providing nationwide interoperability for the first responder community from coast to coast and border to border. It will also result in broadband for rural America faster and less expensively than any other proposal presented so far by any branch of the Federal Government.

Andrew M. Seybold

The East Bay Region is one of 21 jurisdictions that received waivers from the FCC to operate a broadband network on the 10 MHz of 700-MHz spectrum already allocated to Public Safety. The license is currently held by the Public Safety Spectrum Trust (PSST) and the waiver recipients not only have a waiver from the FCC to build and operate their portion of the nationwide network, they have all entered into lease agreements with the PSST for use of the spectrum.

The San Francisco Bay Region came together and formed a joint powers authority, the BayRICS Authority, to develop and operate the broadband network. The BayRICS Authority is currently negotiating an agreement with Motorola to provide the system. Motorola received a $50 million grant from the broadband stimulus funds (BTOP grant) to build out the network. A previous grant funded Project Cornerstone as a proof of concept for the larger LTE network planned for the Bay Region, and this was the network we tested. The report goes into detail about the network, test procedures, actual tests, and results. We have also included more details on all phases of the testing in seven appendices.

The tests were based on real-world incidents that are typical in both metro and suburban areas on a daily basis. The number of first responder personnel assigned to each incident and their functions at the incident and in the command center have been vetted by many within the Public Safety community and, in reality, the number of first responders assigned to the incident for our tests represents a conservative set of personnel on the scene.

It should also be pointed out that these tests were made under ideal conditions. There was no other network traffic, each test was conducted at the center of a single cell sector, multiple times, and the mobile devices were mounted in vehicles using roof and trunk-mounted outside antennas. The backhaul between the cell sector and the network was 30 Mbps and cannot be considered as a choke point in the network. Further, the testing server was physically located at the network center or core so there were no additional data links that could have skewed the results.

A paragraph taken from the conclusions section of the report sums up our findings:

“Based on these real-world tests, we strongly recommend that public safety be provided with at least 20 MHz of contiguous spectrum (10 MHz by 10 MHz). The only way to accomplish this is to reallocate the 700-MHz D Block to public safety and this should be done prior to the build-out of the waiver recipients’ portion of the nationwide network. The cost to build out 10 MHz of spectrum and 20 MHz of spectrum is identical at the time of construction. Later, the addition of this spectrum would add to the cost of the network and require device redesign, adding to the cost of the user equipment. The entire premise of providing public safety with broadband spectrum using a commercial technology is to provide public safety personnel with capabilities they do not have presently at a lower cost than its existing voice communications equipment.”

The full report, as it was submitted to the FCC, is attached to this column in PDF format and will also be posted on our website for future reference. We believe our testing methodology is solid and that the tests, which were repeated multiple times for each incident, were conclusive. In addition to our own findings, Anritsu America was taking off-the-air measurements with its test equipment to verify the total traffic being sent over the network. We thank Anritsu for its support and assistance. I would also like to thank Motorola, the provider of the network, for its cooperation in working with us on this project. Finally, a big thanks to Panasonic, which provided us with seven identical Toughbooks running Windows XP. These units are identical to thousands of Toughbooks that are installed in police, fire, and EMS vehicles around the United States.

The bottom line: Public Safety needs the D Block and the funding to build out the nationwide Public Safety network. If the D Block is not reallocated, Public Safety will end up with a network that will not provide the types of information and videos it wants and needs on a daily basis for incidents that occur multiple times a day in both major metro areas and their surrounding suburbs. Senate bill S.911 provides both the spectrum and the funding that is needed by the Public Safety community. This bill passed through committee with a strong 21-4 bipartisan vote and it needs to be introduced on the floor of the Senate as soon as possible. This will put pressure on the House of Representatives to pass a similar bill and send it to the President for his signature.

Ten years after 9/11, there is no excuse for not providing the Public Safety community with the tools it needs to better serve all of us. This becomes even more important when the Public Safety community has seen layoffs at a local level because of a lack of funding. Doing more with less takes the right tools, and in this case the right tool is a robust Public Safety-only broadband network that has 20 MHz of spectrum available.

Andrew M. Seybold

Cornerstone09-14-11FNL

My view is that our channelized voice systems will be around and needed for at least the next 5-10 years, therefore, continued investment in these systems not only makes sense, it should be a requirement. Progress is being made as you will see below, but even with the definition of mission-critical voice in place I know of no work being done to determine the specific requirements regarding the number of dispatch, coordination, or simplex, talk-around, or peer-to-peer voice channels or circuits that will be required. It is possible that there will be mission-critical voice capabilities on LTE and other broadband networks but that these broadband technologies may not be able to provide the number of voice channels that are used today for major incidents such as wildland fires, etc. It is also possible that broadband voice will not be able to support the number of dispatch areas or zones in use today in major metropolitan areas. It is also possible that the combination of voice and data services will give Public Safety the ability to make changes in the operations to streamline the dispatch and tactical aspects of incidents as well as to operate as it does now.

Where We Are Today; Where We Are Going

As the 700-MHz waiver recipients begin building out their portion of the nationwide 700-MHz broadband network, and as the various committees of the various Public Safety organizations meet and discuss issues, one that keeps coming up is the use of the broadband network for mission-critical voice. I have been saying for a long time now that mission-critical voice (as defined by a recent NPSTC document) is still a long way from becoming real over the LTE broadband network.

However, some progress has been made in recent months. One of the most important elements of Public Safety-grade mission-critical voice has to do with off-network or tactical communications, sometimes referred to by the IT world as peer-to-peer communications. Simply stated, this means the ability for two or more field devices (mobile or handheld) to communicate with each other without having to use a cell site or radio tower system. Many who have discussed this include it as a must-have for times when field units are out of coverage of a network. However, in most cases this type of off-network communications is also a requirement of field units even when they are within network coverage.

Call it what you will—tactical, simplex, talk-around, peer-to-peer—it is the ability for units in the field to be able to communicate directly with each other without any infrastructure required. Today’s Public Safety voice devices all include this feature as standard, but cell phones do not support this mode of operation. I have been skeptical that commercial network operators or others within the LTE broadband community would get behind this mode of communications, but recently, simplex mode communications was introduced at the 3GPP standards body and has been endorsed by some commercial network operators including AT&T, as well as by the U.S. National Institute of Standards and Technology (NIST). In other words, now at least the beginnings of this function are being incorporated into the 3GPP standard for LTE and other broadband wireless technologies. BUT, and this is a big but, it may take years for this to work its way through the 3GPP and be voted on by the membership.

Several federal agencies have funded development work on mission-critical voice over LTE and broadband in general, and several of the bills to reallocate the 700-MHz D Block to Public Safety include additional funding for this type of research and development. However, to date there is no real specification that outlines the number of voice circuits that are or will be needed going forward. If we look back at past major incidents and add up the number of voice circuits that were used at a given incident, is this really the number of voice circuits that will be needed when combined with broadband data services?

For example, if we look at one of the major wildland fires in Southern California over the past few years it is possible to determine how many incident and non-incident voice channels were in use during the incident, but does that translate to how many voice circuits will be needed when we add broadband capabilities into the mix?

The Incident Command System (ICS) clearly defines the roll-out of both the ICS management system as well as the Communications Structure. During a major incident today, the communications leader or someone appointed by him usually completes an ICS form 205, which is the Incident Radio Communications plan that lists the incident name and then radio channel utilization. In most cases, this form is filled out by hand, usually at the staging area where vehicles arriving at the incident report to receive their assignments.

The number of voice radio channels used depends on the size of an incident. During the Tea Fire in Santa Barbara that started on November 13, 2008, burned 1,940 acres, destroyed 210 residences (130 in Santa Barbara, 80 in the county), and caused 30 firefighter injuries, the total number of radio channels in use at the height of the fire was 18 command-and-control channels and 72 tactical or simplex channels used for the fire and by police and other first responders directly involved with the firefighting efforts. Normal operations used an additional 4 dispatch channels and 6 tactical or simplex channels.

The good news is that in California almost all of the fire units that responded from federal, state, and local agencies had multi-channel VHF radios so there was a good amount of interoperable communications available. However, this did not include police, sheriff, highway patrol, and other agencies that were also involved in the firefighting. Coordination between these agencies and the fire command was handled via the dispatch centers and/or the emergency operations center. As you can see, there were a large number of radio channels in use and of these, some of the channels were federal, some state, and others local channels. One of the questions that need to be answered as we add broadband services (data and video) to these types of incidents is how much of the traffic on these channels would be reduced and could a future incident get by with fewer voice channels. Another question is that since this fire covered a large area, could some of the voice channels, in the future, be reused in different sectors? These are questions that can only be answered by those who plan for these types of major incidents and it is their input that will be critical to the development of the requirements for mission-critical voice over broadband systems.

One of the reasons so many voice channels are required during major incidents has to do with the fact that each group assigned to the incident has its own specific task to complete. Since each of these groups must have instant and complete communications capabilities, each group is generally assigned its own voice channel with the commander of each group monitoring both the local working channel and the channel on which they then talk to the next higher ranking officer at the incident. This system has worked well for many years and has provided a highly reliable way of ensuring that anyone who needed help could get on a radio and ask for it, and that someone else, either local to them or within radio range, could hear the call and respond accordingly. Without this type of reliable communications there might have been more injuries or even deaths as a result of someone calling for help and that call being unanswered.

In an ideal world it would be wonderful if every first responder had all of the capabilities needed to do their job and protect themselves and the public in a single device. Such a device would give them all of the voice, video, and data capabilities they need, when they need it. But we don’t have this type of device today. First responders cannot take the time to dial a phone number, and many times they do not have two hands available to change the status of the wireless device or make a menu selection. They need to know that simply by pushing an emergency button or calling for help their location and their need for assistance has been heard and that help is really on the way.

Technology is advancing rapidly and the first responder community, for the first time ever, is embracing a commercial and readily available technology for broadband (LTE). Hopefully, Congress will give the first responders the spectrum they need to build out a nationwide broadband network that will provide fully interoperable communications from border to border and coast to coast. Broadband will provide video for those responding to an incident, which is like giving sight to the blind. It will enable a swat team commander to see, on a mobile device, exactly what his snipers are seeing through their high-powered rifle scopes, all of which translates to better protection for both the citizens they serve and for themselves.

In the future, there is no doubt in my mind the Public Safety community will be able to have a single device that will permit voice, data, and video, but when will that future be? There are, at the moment, about 100 different answers to that question. The general consensus from those working with the technology is that some level of mission-critical voice can and will be available over LTE broadband networks. The remaining questions are how many of the mission-critical voice requirements can actually be met with LTE broadband or future broadband technologies, and how long will it take to be able to prove to the Public Safety community that LTE broadband can provide both voice and data services?

The bottom line is that today’s mission-critical channelized voice systems, and the new systems being deployed, developed, and planned, need to continue to be funded to ensure that when the time comes, the capabilities of LTE broadband can be weighed against the needs of the Public Safety community. If there is a perfect fit, the transition from channelized to broadband mission-critical voice should begin. Perhaps some of the channelized spectrum could be returned to the FCC for reallocation to others but this process should not, today, be viewed as something that will happen overnight but rather that it could take years to accomplish.

Is voice coming to LTE broadband? Yes, it’s the when that is in question. Is mission-critical voice coming to LTE broadband? I hope so, but in the meantime, not maintaining or building new mission-critical Public Safety voice systems should not be an option considered by any local, state or federal agency!

Andrew M. Seybold

LTE or fourth-generation (4G) wireless broadband was designed and implemented primarily as a data over broadband technology. Voice in the form of Voice over IP, which is being designed to implement voice calls in the traditional cellular fashion of dialing a number and completing the call using the LTE network as transport, is being developed. The issue is whether LTE can and will support other types of voice services, specifically Push-To-Talk (PTT) voice and most importantly, PTT off-network, when units are out of coverage of the network or when they need short-range communications in buildings and in other areas where the network does not provide coverage.

The standards for LTE are largely controlled by the 3GPP, an organization made up of hundreds of commercial members including chipset companies, infrastructure vendors, network operators, handset companies, software developers, and others. In order to add mission critical voice requirements to the LTE standard, the Public Safety community must petition the 3GPP for its inclusion AND there must be a number of other members of 3GPP that concur. Once (if) this happens, the amendment to the standard is assigned to a future release of LTE and when that release is being worked on, the amendment will be considered.

In order for the amendment to the standard to be considered, all of the requirements must be defined and support must be garnered from members of the 3GPP. At present, there is no incentive for network operators that largely drive the direction of 3GPP, to embrace mission critical voice, especially the part of mission critical voice that is of paramount importance to Public Safety: The ability to communicate between devices without having to make use of a network. Commercial network operators are not inclined to agree to this type of voice communications because they won’t have control of their customers and the minutes of use cannot be billed to the customer.

Therefore, Public Safety will have a difficult time convincing the 3GPP to address the issue of mission critical voice. If a non-standard workaround can be and is developed, it would mean that the devices used by Public Safety would not be nearly as standard as the devices being envisioned today for data and video, thus the cost of these devices would be considerably higher.

However, voice over LTE will happen. It might take longer than many people believe, and it will certainly be implemented in stages. The first voice over LTE smartphones will be available on commercial networks by the end of this year, and the first PTT LTE devices will be tested. Initially, neither of these voice services will meet all of the voice requirements of the Public Safety community. The first PTT service will probably be PTT over LTE for non-mission critical voice communications that will be bridged to existing narrowband P25 voice systems in order to provide for interoperability between narrowband voice and LTE PTT services.

For those trying to plan upgrades to or expansion of their existing narrowband voice networks, it is possible that voice over LTE, both on and off-network, will eventually be developed to provide all of the voice requirements for mission critical on and off-network services. If there is funding for research and development available from the federal government, the time frame will most likely be shortened. In either case, it will take time to first build out the nationwide broadband network, then it will take time for Public Safety to learn how to incorporate data and video into their everyday incidents and then how to integrate voice over LTE into their systems over time.

It is imperative, therefore, that those making decisions about the existing narrowband voice spectrum now available for Public Safety realize that this process could take many years. The commercial community is deploying its forth generation of wireless technology in thirty years while Public Safety is deploying its second generation of voice (P25) in fifty years. One advantage to Public Safety moving to a commercial standard for the first time is that it can piggyback on the standards developed for the commercial community and follow rather than lead the commercial networks with new and upgraded technologies, features, and functions. When it comes to voice over LTE, some of the requirements may not be relevant to the commercial network operators and vendors, thus the development of this functionality may take longer than functions driven by the commercial network operators.

LTE will be able to provide some of the voice capabilities needed by the Public Safety community. The questions remaining are how long will it take to implement the rest of these requirements, how much will it cost, and whether it is better in the near future to integrate voice and data services in the back-end network but not necessarily over the airlink. There is a lot of work to be done to transition from traditional narrowband voice to voice over LTE, and at this point no one knows how long it will take or even if all of Public Safety’s requirements can be fully met on a broadband network.

What Is Mission Critical Voice?

At the moment, there is no “official” definition for mission critical voice; both SAFECOM and NPTSC are in the process of flushing out a number of definitions. But the two below, one developed by Motorola and one by me, are pretty close to what is necessary to provide true mission critical voice communications that are Public Safety grade.

From Motorola http://ezine.motorola.com/government?a=99

“Mission critical voice communication reflects the harsh realities on the emergency management scene: when every other commercial system is down, you expect mission critical voice to be there. The exacting standards for mission critical networks and devices disqualify many nascent technologies and devices in favor of proven, reliable standards. In a mission critical environment, all aspects of a device or technology must achieve interoperability, reliability, coverage, capacity, control and instant, real-time communications.”

“In an emergency, mission critical voice remains the single most powerful tool public safety and government agencies have at their disposal to ensure the safety and well-being of first responders and the citizens they protect,” says Thomas Quirke, director of Solutions Marketing at Motorola.

And the one I have developed is as follows:

1)   Mission critical communications

1. Communications between two or more parties that must be conveyed no matter what the circumstances and it must be delivered in a timely (immediate) manner with clarity.
2. These communications must be 99.999% reliable regardless of the conditions.
3. This applies primarily to voice services but should also include data and video services during emergency situations
4. An emergency is any event or incident where life and/or property is in danger, and includes the safety of the responders.

Mission Critical Voice Today

Today, mission critical voice is provided to the Public Safety community using narrowband voice channels in one of eight different portions of the spectrum. These channels are dedicated to Public Safety and the larger an agency is, the more area it has to cover, or the denser the population in its area of responsibility, the more channels it will have licensed to a given agency, city, county, or region. For a more complete explanation of the way in which mission critical voice communications is used today, please refer to Appendix A.

There are those who are working toward the goal of having the Public Safety broadband nationwide network replace today’s mission critical narrowband voice networks. There are many who believe that this will be possible to accomplish in only a few years, while others doubt it can be accomplished within the next decade, and some who believe that voice over broadband won’t be able to replace the need for narrowband voice channels beyond a decade, if ever.

The first thing that is required in order to determine whether broadband networks will be able to replace narrowband voice systems for mission critical voice is a common set of system requirements based on the needs of the Public Safety community. Many of those who are proposing the use of broadband for all of the Public Safety community’s needs for voice services do not fully understand the vast differences between Public Safety voice and voice over an existing cellular system and how different the requirements are for each. Working toward the goal of voice over broadband is fine but only with the understanding of exactly what is required by the Public Safety community and then developing hardware and software that may be able to meet all of these requirements at some point in time.

Mission Critical Voice Over LTE Impediments

The following is a partial list of the impediments that will present challenges to the development of mission critical voice over LTE including off-network, one-to-many communications:

1)     LTE is the fourth-generation standard for wireless broadband and voice over IP (VoIP) will be added for typical cellular phone calls.

1. Neither the existing release nor future releases address the issue of mission critical voice over LTE or the issue of off-network, one-to-many direct voice communications.

2)     LTE, while a worldwide standard for broadband services, will not be using a common portion of the spectrum.

1. Today, LTE is being deployed in more than fourteen different portions of the spectrum worldwide with many different off-sets between transmit and receive frequencies and as a time-division-duplex (TDD) technology using the same transmit and receive portions of the spectrum. This makes it even more difficult to develop a standard for off-network communications.

3)     Today’s LTE devices are controlled by the network and NOT only at the device level.

1. If off-network communications is required, then additional intelligence will have to be built into the devices in order for them to be able to select an LTE voice channel manually or in some other fashion

4)     LTE commercial devices have an output power of 200mw as opposed to handheld LMR radios with power levels of 5 watts or more.

1. Therefore, the difference in in-building communications will be substantial unless LTE devices are designed with increased power levels for off-network communications.
2. However, the power levels will have to be different for on-network and off-network voice since higher-powered devices (with the current LTE specifications) will simply shut down a standard LTE network.

5)     How many voice channels can be supported by LTE both on and off-network?

1. If LTE is to be used for voice dispatch, it will have to provide multiple, separate one-to-many on-network voice channels in order to replicate existing Public Safety narrowband voice systems.
   1. Many cities and counties make use of multiple dispatch channels as well as city or countywide channels (see appendix A). The number of channels required in major metro areas or large counties could run as high as fifteen to twenty separate dispatch channels. When using off-network voice communications, if it is possible to accomplish this, the number of off-network channels will have to be substantial.
2. In a major incident such as a wild land fire, upwards of seventy discrete one-to-many, off-network voice channels will need to be deployed during the incident.

6)     How many voice channels will be available in a given metro area for one-to-many voice communications?

7)     What impact will adding PTT and voice communications have on the network’s ability to handle data and video at an incident?

1. Most daily incidents will take place in a confined area within a jurisdiction and will usually be covered by only a single cell sector. Therefore, the total bandwidth available for the incident will have to be shared between voice and data/video services. Using Voice over IP, voice must have priority on the system.
   1. Further, if thirty or forty PTT users are registered within a single cell sector, the amount of data/video capability at the incident will be limited because of the requirement for voice within the same cell sector.

8)     What additional infrastructure will need to be added to the Public Safety LTE network in order to implement one-to-many voice services?

1. eMBMS (Enhanced Multimedia Broadcast Services)?
2. Other?

9)     Since LTE’s transport layer is based on UDP (User Datagram Protocol) rather than TCP/IP, this means that packets that are not delivered or that are delivered with mistakes in them are not re-sent and are basically thrown away.

1. How will LTE’s Quality of Service (QoS) and Priority features ensure that
   1. Voice packets have priority over data packets
   2. Voice packets arrive in the proper sequence and with no errors or
   3. The user devices are capable of error correction to ensure intelligible voice being received?

10)  How will voice traffic, specifically PTT voice, be routed when a user is out of his/her prime area of operation?

The above list is only a partial list of the issues that must be dealt with and solved prior to LTE being able to support what is defined as one-to-many voice services for Public Safety.

Conclusions

IF LTE broadband can meet both the voice and the data requirements of the first responder community, a single device could be deployed that would provide not only data/video interoperability, but voice interoperability as well. This would be an ideal situation and one that is worth pursing. However, existing narrowband spectrum should not be reallocated for other uses until such time as LTE broadband can and does meet all of the requirements for Public Safety mission critical voice as well as data and video services.

Organizations such as NPSTC are working on defining the specific requirements for voice over LTE for Public Safety and there are those both within the federal government and within the vendor community that believe Public Safety will soon be able to use a single device for both mission critical voice and data on the common LTE broadband system. Others believe that some form of PTT over LTE, perhaps P25 digital PTT, will be able to be used over LTE but in conjunction with existing narrowband P25 voice systems.

Whatever the case proves to be, it is imperative that Public Safety not lose any of its meager spectrum holding for narrowband voice until voice over LTE is proven and readily available. As important as data and video are as new services to the Public Safety community, in the end, voice communications are the most critical form of Public Safety communications and it must remain mission critical, easy to use, and available on a moment’s notice. If it is not, Public Safety agencies will not be able to perform their tasks efficiently and will, in fact, place themselves and the public in harm’s way.

The most sensible approach for the short term is to work with vendors to develop dual-mode devices capable of LTE data/video services as well as narrowband P25 capabilities on both the 700 MHz and 800-MHz bands currently assigned to and licensed by Public Safety agencies. Such devices should become readily available within the next few years, and while they will still cost more than commercial wireless devices such as smartphones, these devices can and will provide both broadband data/video and voice over P25 using the narrowband channel capabilities. There will still be issues regarding voice interoperability with systems on other portions of the spectrum, but for the next few years there are workarounds that can be implemented to minimize, but not eliminate, the issue of voice interoperability.

LTE may be able to meet all of Public Safety’s requirements for fully interoperable voice and data services but that has not been proven yet and I believe if it happens at all it is many years in the future. In the meantime, LTE for data and video should be deployed as quickly as possible, and workaround solutions for interoperable voice should continue to be implemented on a local, area, regional, and statewide basis. To stop the drive for voice interoperability on the existing narrowband voice channels while waiting to determine if LTE can, in fact, be effectively used for both voice and data mission critical applications would be dangerous not only to the first responders but to the people they serve.

Andrew M. Seybold

Appendix A:

Mission Critical Voice Use

Voice channel requirements for Public Safety include the following:

1)     One or more one-to-many, on-network voice channels for dispatch.

1. Dispatch channels must be capable of one-to-many communications since it is imperative that not only the units required for the dispatch are notified but that those in proximity to the incident be made aware of the incident and that the field commanders be aware of the dispatch and the incident as well.
2. After the dispatch is made, either the units responding are directed to use a different one-to-many, on-network channel for unit coordination or they remain on the primary dispatch channel until the first unit(s) on the scene report the status of the incident.
3. Usually fire and EMS personnel are dispatched on one set of dispatch channels while police agencies are dispatched on a different set of radio channels.
4. In large populace and metropolitan areas, there need to be multiple dispatch channels. Normally they are assigned by geographic area within the agency’s jurisdiction.
5. In addition to the dispatch channels, each agency normally has one or more jurisdiction-wide command and control channel for incident coordination.

2)     On-scene communications

1. The first unit arriving on the scene of an incident will give both the dispatcher and the other units responding to an incident a report of the situation as visually observed upon arrival.
   1. This message needs to be heard by ALL of those responding, the dispatcher, and those within the area and/or line officers responsible for manpower and equipment allocations.
   2. In both police and fire incidents, if the incident involves additional responders, the incident is normally assigned to an off-network channel to free up the dispatch channel and to provide on-scene communications for those at the incident. Again, fire and EMS will normally operate on one or more off-network channels while police will operate on others.
   3. As the incident grows, additional off-network channels are assigned so each group at the incident has its own working channel. For example, in a hostage situation, the SWAT team may be assigned one discrete channel, uniformed officers on the scene another, detectives yet another, and fire and EMS support yet additional channels.
   4. The larger an incident becomes, the more off-network channels need to be assigned.

3)     Off-network communications on different channels are a necessity for Public Safety. Oftentimes there are multiple incidents in progress at the same time, separated by some distance, and even more off-network channels are required in the day-to-day operation of Public Safety agencies.

Narrowband Voice Channels Currently Licensed to Public Safety Agencies:

Note: Cleveland, Buffalo, and Detroit are using shared NTIA channels in the 421-430-MHz band
Note: There are a few 220-MHz systems in use in other areas such as Long Beach, CA.

As the chart above illustrates, today’s Public Safety mission critical voice channels are spread across seven vastly different portions of the spectrum. It should be noted that except for the 700 and 800-MHz voice allocations, all of the other portions of spectrum allocated to Public Safety are shared with other services. It should also be noted that a radio system operating on the 30-MHz band, 150 MHz, 450 MHz, or 800 MHz will have different coverage capabilities on each; the higher in the spectrum that you operate a system, the more infrastructure is required to cover the same given geography.

Different types of narrowband voice services and technologies available and in use in the various segments of the spectrum are as follows:

One-to-many voice communications, available on multiple on and off-network channels, is a prime requirement for Public Safety communications but is not a requirement for commercial wireless networks.

Public Safety Voice Interoperability

Some in Congress and on the House Energy and Commerce Committee are pointing to a March 18, 2011 memo from the Congressional Research Service (CRS)[1] to assert that the Public Safety Community has wasted more than $13 billion in federal grants for radio communications systems since 2001. In reality, the grants have totaled less than $4 billion and they have, in fact, provided for a higher level of Public Safety interoperability than ever before. In order to fully understand the impact of these grants, it is important to understand the many and varied issues that must be addressed if the ultimate goal of nationwide interoperability is to be achieved for both voice and data services for Public Safety.

Interoperability between various Public Safety agencies had been an issue long before it was brought to public attention during 9/11, Katrina, and other disasters. Articles dating back several decades have pointed out both the need and the issues that must be overcome in order to provide the Public Safety community with interoperable voice and data.[2] Indeed, Public Safety and the Big 7 state and local government associations initially secured the 24 MHz derived from digital TV transition in the wake of the communications failures first responders experienced at the site of the domestic terrorist bombing of the Alfred Murrah building in Oklahoma City in 1994. At that site, firefighters and police officers conducting search and rescue could not speak to each other on their radios within different floors of the building and had to resort to talking to dueling command centers set up outside the site, and couriers running back and forth between the two command centers.

Three major factors have significantly hindered Public Safety’s efforts to achieve mission-critical voice interoperability:

1. Public Safety’s currently allocated spectrum is in small segments spread out over at least seven different portions of the radio spectrum.
2. Because this spectrum has been in use by Public Safety for many years, interoperability must start at the local level, then the regional, state, regional interstate level, and finally at the national level (and at international borders as well).
   • Most of the money expended to date has resulted in better interoperability on a local, regional, and state level, interstate regional, and on international borders, but because of the lack of enough spectrum in any given FCC allocation, this process is slow, tedious, and expensive.
   • The Public Safety broadband network will be built on greenfield, that is, unused spectrum. Therefore, it will be possible to design and implement this new network as a fully interoperable network from the beginning, something that has never before been possible for the Public Safety community.
3. Within each portion of the allocated spectrum, different Public Safety departments make use of different types of radios and radio configurations to meet their own individual coverage requirements.

The main reason for a lack of Public Safety voice interoperability is the fact that while the FCC has continued to allocate more spectrum over the years for use by the Public Safety community, these new allocations have been in very different portions of the spectrum. Today, Public Safety voice communications are authorized in small segments of the spectrum from 30 MHz up to 800 MHz, and except for the spectrum in the 700 and 800-MHz bands, the Public Safety channels are comingled with channels used by business, taxi services, truckers, paging services, and others. In short, there has never been an allocation of enough spectrum in a common radio band to permit all of the various Public Safety agencies to migrate to a single portion of the spectrum and be able to interoperate between all agencies.

Note: Cleveland, Buffalo, and Detroit are using shared NTIA channels in the 421-430 MHz band
Note: There are a few 220-MHz systems in use in other areas such as Long Beach, CA.

As the chart above illustrates, today’s Public Safety mission-critical voice channels are spread across seven vastly different portions of the spectrum. It should be noted that except for the 700 and 800-MHz voice allocations, all of the other portions of spectrum allocated to Public Safety are shared with other services. It should also be noted that a radio system operating on the 30-MHz band, 150 MHz, 450 MHz, or 800 MHz will have different coverage capabilities on each; the higher in the spectrum that you operate a system, the more infrastructure is required to cover the same given geography.

When those outside the Public Safety community look at the spectrum allocations already made, they oftentimes do not take into account that the 4.9-GHz spectrum (50 MHz) is not suited for wide-area broadband service. In reality, it is designated for low-power, local communications just as today’s unlicensed Wi-Fi bands are allocated for citizens’ use. The average coverage of a single 4.9-GHz access point is 300 feet or less, and in most systems today, this spectrum is used for point-to-point communications for video transmissions from fixed-location cameras, or for on-scene local broadband services. This spectrum is not available or useful for Public Safety as part of the nationwide broadband network that is being planned to provide wide-area coverage across the nation.

Today, in many urban areas there are not enough radio channels in a given portion of the allocated spectrum to meet the requirements of Public Safety. Radio signals do not stop at city, county, or state (or international) boundaries, therefore the channels in use in a given area must be coordinated with adjacent users to prevent or minimize interference between systems. In many areas this means, for example, that the police departments will operate in the 450-MHz portion of the spectrum while fire and emergency medical services (EMS) units will operate in the 150-MHz portion of the spectrum. Providing interoperability between police, EMS, and fire in these areas requires either specialized equipment in the dispatch centers to patch channels together or the installation of two or more radios in each vehicle; which is an expensive and ineffective method of obtaining interoperability between systems.

If Public Safety had been allocated sufficient spectrum in any one of these bands to satisfy the number of radio channels required for true nationwide interoperability, the result would have been twofold:

1. We would, today, have a truly interoperable voice system nationwide.
2. The cost of Public Safety radio equipment would be at least 50% less than what it is today because it could have been built to operate on a single portion of the spectrum, providing[3] economies of scale and reducing per unit price for Public Safety radios. Today, equipment vendors must build radios for a specific portion of the spectrum, and therefore the quantities they produce for each portion of the spectrum are less.

Other Factors Hindering Mission-Critical Voice Interoperability

Because the narrowband voice spectrum is already heavily used, nationwide interoperability cannot be achieved until it is first made available on a local, regional, and then statewide basis. Much of the funding that has been granted to Public Safety since 2001 has in fact resulted in better regional and statewide interoperability. From 2001 until today, the number of new regional and statewide systems constructed and operational has grown rapidly as the various jurisdictions have sought out their own ways of providing mission-critical voice interoperability.

For example, in California, technology advances have provided fire service with the ability to purchase and install radios capable of more than 300 channels in the 150-MHz band. There is a standard plan in place so that most of the fire departments can and do have interoperability not only between city, county, and state fire units, but also with federal government fire units. However, in major cities such as San Diego, Los Angeles, and San Francisco, there are not enough of these channels to provide for day-to-day fire operations, so fire departments are operating on other portions of the spectrum. During major incidents, agencies responding from out of the area are not able to directly communicate with fire equipment from the large cities without either a second radio in each vehicle or some other form of non-automatic channel sharing equipment.

Many regions have built and installed regional radio systems that are used as interagency communications systems during mutual aid situations. Many of these serve as overlay systems since very few have the channel capacity to serve all of the various local entities. This also requires multiple radios in each vehicle. Several states such as Wyoming, Florida, Vermont, Montana and others have recently built or are in the process of building statewide interoperable mission-critical voice systems in order to provide statewide interoperability, but in many cases, these systems augment rather than replace the local systems that are still needed on a daily basis to meet the capacity requirements of each local Public Safety agency.

In a recent memorandum from the Congressional Research Service (CRS)[4] dated March 18, 2011, the data used as a baseline was taken from a survey conducted by the National Emergency Management Association (NEMA).[5] This report was, in fact, based on Emergency Management Association directors’ estimates of funds thought at the time to be necessary for states to achieve full statewide interoperability and did not, as portrayed in the CRS report, reflect actual amounts of funding received by the states and local agencies. Further, specific grant programs put requirements on accessing the funds that led to an emphasis on local, regional, and statewide interoperability (as opposed to nationwide), and there were conflicting requirements among and between grant programs causing a lack of greater interoperability.

When working toward the goal of both voice and data interoperability as is the desire of the Public Safety community, it should be stated again that trying to provide interoperable voice services when the agencies are already using spectrum spread out over seven different portions of the spectrum and on which, today, during peak hours, there is already severe network congestion that must be approached from a local, then regional, then statewide basis. However, the opportunity, with the 700-MHz broadband network is to design and implement it on spectrum that is unused, therefore, the network can be constructed from the ground up based on the requirement for nationwide interoperability.

Different Types of Systems

In addition to the shortage of radio channels in any given portion of the allocated Public Safety narrowband spectrum, there is yet another issue that makes mission-critical voice interoperability even more difficult. Namely, over the years, each local city, county, and region has built out different types of radio systems using differing technologies. Therefore, even two agencies in the same geographic area operating within the same portion of the spectrum are not always able to communicate with each other. Mission-critical voice communications systems, today, make use of two very different air interfaces. Many are still using the 30-year-old voice technology referred to as analog or FM voice communications. Newer systems have moved to the digital voice standard known as P25 or APCO project 25, which is a standard for digital voice systems. However, even within these two different types of voice systems, there are many variations of how they are deployed. Small rural areas might use a simple radio base station and radios in vehicles. Larger departments might elect to repeat all of the traffic on a given channel using repeater stations, while others have tied a number of repeaters together in what are called simulcast systems. Still others are grouping between five and twenty radio channels together into what is known as a trunked radio system. Not many of these radio systems are compatible with the other types, and, in many areas, the common way to provide interoperable voice communications is to use unit-to-unit, direct, or off-network voice channels so those on the scene of an incident can communicate with each other (provided they are all operating in the same portion of the spectrum).

The chart below reflects the complexities of working toward the goal of providing full interoperable mission-critical voice communications. As it shows, there are many variables that must be considered, and the grants have been provided on a city, county, regional, or state basis with no substantial coordination between grants or agencies receiving the grants. The reality is that the grant funds already provided to Public Safety have advanced the state of interoperability with an emphasis on local-to-statewide interoperability, and so only achieved on a local, regional, and statewide basis.

Possible Combinations of Systems that need to be Interoperable:

Public Safety needs the D Block spectrum and it needs federal funding in order to accomplish this goal. If enough spectrum is not made available this time, or if funding is lacking, the only option is to duplicate the mistakes that have resulted in the lack of nationwide interoperable voice and the problem and issues described above.One reason Public Safety must have enough contiguous spectrum on a nationwide basis for broadband services is to make sure that systems being built adhere to nationwide standards, use the same technology, adhere to the same system design and, therefore, provide for full interoperability from the very beginning.

Public Safety can never again be placed in the position it has been in over the last thirty or more years where spectrum is not contiguous, there is not enough to handle the demands in major metropolitan areas, and there is a lack of financial resources to build the nationwide interoperable broadband network that will, for the first time, provide Public Safety with the resources it needs to accomplish the goal of true interoperability while realizing the cost savings of using a worldwide air interface standard (LTE) to provide Public Safety with economies of scale for the first time.

Given (1) the number of different portions of the spectrum in use today for Public Safety mission-critical voice communications, (2) the insufficient amounts of spectrum within each portion of spectrum provided to Public Safety, (3) the multiple types of systems in use within each portion of spectrum and throughout all of the different portions, and (4) the focus on interoperability for mission-critical voice on local, then regional, then statewide, and only recently on a nationwide level, the funds provided to Public Safety have been used wisely and have achieved much improved interoperability within and among voice systems in most localities in the United States.

Conclusions

The Public Safety community has neither wasted the grants allocated since 2001, nor wasted any of the valuable and very limited spectrum provided. The Public Safety community has accomplished much with the little it has had to work with over the years. Today, more regions of the country have interoperable mission-critical voice communications than ever before, but full nationwide mission-critical voice interoperability is not achievable over the course of the next decade or two given the multitude of spectrum allocations, the differences in technologies being deployed, and the lack of a nationwide long-term plan.

We also believe that given enough broadband spectrum (20 MHz) and funding, Public Safety can and will build out a nationwide, mission-critical broadband network that will provide the level of interoperability needed on a daily basis for data and video services. Over time, this network will serve as a model to solve the nationwide voice interoperability issues that remain.

Andrew M. Seybold
CEO and Principal Consultant
Andrew Seybold, Inc.

[1] Congressional Research Service, Memorandum to Congressional Distribution, March 18, 2011 from Linda K. Moore
[2] Volume 1, No. 5, December 1980, Andrew Seybold’s Report on Mobile Emergency Communications. A Limited Natural Resource
[3] Tetra radio prices in Europe are approximately 50% of P25 prices in the United States because they are on a common portion of the spectrum and one radio can be built and shipped to all European Countries
[4]Congressional Research Service, Memorandum to Congressional Distribution, March 18, 2011 from Linda K. Moore
[5] Letter from NEMA to CRS: http://www.psafirst.org/uploads/documents/CRS_Letter_FINAL_05_27_11.pdf

Some of you have used 3G data services from commercial operators so you already know the advantages of having wireless broadband capabilities available to you, even though you also learned that during incidents it is not always possible to make use of broadband due to network demand from civilians and the press. Those who have not yet tried wireless broadband will also find how valuable a tool it can be. For all branches of Public Safety, it is like giving sight to the blind (video) and providing better information to those responding to and at an incident. The idea of having a common broadband network available to Public Safety on a nationwide basis will change the way Public Safety responds to and handles incidents. It will end up saving first responders and citizens lives, and can even help keep an incident in check that could easily have escalated into a larger one.

Public Safety Broadband Spectrum

At the moment, Public Safety has access to 10 MHz of broadband spectrum in the 700-MHz band and the Public Safety community is lobbying hard to have an additional 10 MHz of spectrum allocated to Public Safety in order to have enough broadband spectrum to meet its needs. This additional spectrum will only be made available if Congress and the Executive Branch can pass and sign into law, a bill that will take the D Block (the 10 MHz of spectrum adjacent to the Public Safety spectrum) off the auction block and make it part of the Public Safety-only spectrum allocation. A lot of hard work is going into making this happen and the Executive Branch as well as many in Congress are headed in this direction but it will still take additional effort to ensure that a bill passes in both houses of Congress and is sent to the President for signature.

Meanwhile, some in the commercial community, and within the FCC, still maintain that the D Block should be auctioned to the highest commercial bidder and that this bidder should work with Public Safety to build out a nationwide system that would be shared between the commercial auction winner(s) and the Public Safety community. This is not practical for a number of reasons including the fact that during incidents demand for broadband services peaks for both Public Safety and commercial customers.

In the meantime, the FCC has granted waivers to some jurisdictions to begin building out portions of the nationwide broadband network in the existing 10 MHz of spectrum already allocated. Recently, we ran exhaustive tests on one such system in the San Francisco Bay area and determined, as was predicted by ourselves and many others, that 10 MHz of spectrum is not sufficient to provide Public Safety the broadband capabilities it needs at most incidents, and certainly not enough for a major, localized incident. I say “localized” because during these types of incidents the resources of Public Safety responders are usually confined to small geographic areas and the need for broadband services within and around the incident will be high, especially if video is used to help manage the incident. While we are not prepared to release our test results at this time, I will state that we found that within one-quarter to one-half mile from the center of a cell site, the maximum data rates available were in the order of 10 Mbps down to devices in the field and 6 Mbps from the devices back to a command center. When we moved one to two miles from the cell center, the data rate dropped to 6 Mbps down and 4 Mbps up, and by the time we were three-and-one-half to four miles from the center, the data rates had dropped to 4 Mbps down and 2 Mbps or less up.

This is lesson one for Public Safety: The further you are from a cell site, the slower the data rate, and at the edge of a cell, the data rates drop off dramatically. Another lesson from these tests is that when the network was overloaded, that is, we tried to push more data and video over the system than it could handle, not only was the last data or video unusable, it also rendered existing data and video transmissions that were already in use unusable or at least unstable.

LMR and LTE: Some Differences

LMR systems for Public Safety are designed to be one-to-many voice systems (some slow-speed data), usually with high-powered tower or mountain-mounted base stations, high-power mobiles for vehicles and even HT’s have what, by cellular standards, is considered to be high power. In addition, simplex, talk-around, or tactile channels are widely used and the HT to HT range is sufficient to penetrate into buildings or talk over distances of several miles. A typical HT has a power output of about 5 watts. Now compare that to an LTE device with a power output of 200 milliwatts. That is a BIG difference in power and therefore, LTE systems cannot be designed in the same way as LMR systems.

Let’s look at some of the differences:

LMR Base Station   / LTE Broadband Cell Site

• High-level sites   /   Low-level sites
• High-power transmit   /   Low-power transmit
• Transmit as needed   /   Transmits 24/7 (all the time)
• Coverage 20-40 miles   /   Coverage 1-3 miles
• Omni-direction antennas   /   Sectored antennas (3 sectors per site)

Obviously, there are many different types of LMR configurations; I have chosen to use a plain vanilla configuration for the example here. One way to visualize the LTE system is that each tower and each sector on the tower transmits on the same portion of the spectrum and receives on another portion of the spectrum (FDD), and every cell site uses the same spectrum. This might equate to a sophisticated simulcast system with many different sites, and since all cell sites are using the same spectrum, there can be interference between two or more cell sites and this interference has to be managed. This is done in both the design and operational phases of building a network and this has to be factored in when building adjacent to Public Safety systems. Say, for example, City A built out a system and then the County built out its own. The areas of concern would be the overlap areas where the cell sites of the County system and the City system both cover the same area. Careful engineering is required to minimize this interference because it will result in even less data throughput.

Something that must be considered in the budget process is the fact that the electric bill for each site will be $200-$500 per month depending on the complexity of the installation. So if your system is to make use of 50 sites, you should expect to see electric charges in the area of $10,000 to $25,000 per month.

LMR Mobile   /   HT LTE Devices

• High power (5 to 100 watts)   /   Low power (200 milliwatts)
• External antennas   /   Mobiles external, handheld built-in antennas
• Talk around/simplex   /   Must be in range of a cell site
• Battery life: at least one shift   /   Depends on data usage
• Channel change by user   /   Channel change by network
• External spkr/mic   /   Built-in screen/display

You can already compare LMR and LTE-like devices by comparing your own HT to your own cell phone. Your HT has a large battery, an external antenna, and speaker and microphone. Your cell phone’s antennas (multiple) are built in, the battery is very small compared to your HT, and while most commercial devices have speakerphone capabilities, they do not have the same audio output as your HT since they are designed to be held up to your ear when talking.

Other Differences:

LMR /   LTE Broadband Backhaul

• Wireline/control station   /   Fiber/microwave
• Low capacity (voice slow-speed data)   /   High capacity (+30 Mbps per site)
• Dumb networks (exception: trunked)   /   Smart cell sites/smart network core
• Set and forget (routine maintenance)   /   Modify network perimeters on a real-time basis

There are many more differences but I have included the major ones here. In more urban areas where data capacity requirements will be heavier, more cell sites, closer together will be required.

One example of this is Santa Barbara County, which uses six high-level sites on VHF and simulcast for the County Fire Department. Verizon covers the same area with sixty to eighty cell sites, some of which are used to increase capacity in the City of Santa Barbara. My estimation is that an LTE system for Santa Barbara County will require between fifty and sixty cell sites in order to provide the required broadband coverage.

LTE broadband networks will cost more to build and to operate than LMR systems covering the same areas. However, these added costs will prove to be worthwhile by opening up a whole new way of sending information to and from the field and incidents. Video cameras will be an important tool for Public Safety as well as building plan downloads, and even routine license plate checks. In addition, field personnel will respond to incidents better prepared for what they are heading into, and more resources can be more quickly added to an incident, preventing it from escalating. Another advantage will be the ability to bring in outside expertise by sending video and audio to experts remotely from a scene. For example, suppose you are faced with a device that could be or is a bomb and your bomb squad has no experience with the type of device. There are bomb experts around the country and around the world that could be added to a live video feed and perhaps recognize the bomb type and assist your bomb squad in the proper way to handle the device.

LTE broadband will change the way Public Safety does business. The changes won’t be instantaneous; they will be gradual over time. The Public Safety community will also have to learn how to manage the bandwidth available during an incident. There will be plenty of applications available to assist, but no matter how much spectrum is available, it is still shared spectrum and priorities as to the type and amounts of data that can be used will have to be managed on an incident-by-incident basis.

I expect initial deployments to become overloaded at first as departments try using lots of video and data services over the network. There will be a learning curve, and it will take some time. However, just as using our smartphones for Internet access, texting, and voice are second nature to us (with others managing the network resources on our behalf), so, too, will Public Safety’s use of LTE. In my presentation, I showed several pictures of today’s command centers and mobile command vehicles and then pictures of what these centers and mobile command posts will look like in the future. To get an idea, visualize a TV studio or an ESPN vehicle parked next to a stadium where there is a ball game in process. The operators are constantly choosing which camera angle to provide the viewers, cueing up other scenes and even having instant replays available for viewers. The difference here is that the viewers will be those involved in the incident command structure who will want to see what is going on in real time to help them make better decisions faster.

Wireless broadband services for Public Safety will transform many things, giving personnel more information than they have ever had before. However, broadband will not replace voice. Voice is and will remain the mission-critical lifeblood of the Public Safety community. There is a truism that a picture is better than a thousand words and this will be the case in our LTE broadband future, but LTE broadband will not replace a voice radio when the message to be transmitted is, “Officer needs assistance!”

Andrew M. Seybold