Push-To-What?Thursday, March 27, 2008
Let’s start with a quick history refresher. Push-To-Talk (PTT) has been used since the first police radios were installed in the 1930s and was deployed by the armed forces during the First World War. With PTT, the talker pushes a button on the radio to turn on the transmitter so he or she can speak over the airways. During this transmission, the talker cannot hear anyone else on the radio channel, but everyone on the same channel can hear him or her. This is called one-to-many communications and it is a vital form of wireless communications for first responders and others who need to know what is happening around them.
For many years, Nextel was the only commercial wireless provider to offer PTT services. Many of its customers had converted from two-way radio to cellular on the Nextel network, but they wanted, and in some cases needed, to be able to continue using PTT and one-to-many communications. As Nextel’s customer base grew, a number of first responder organizations used the network but not as their primary communications channel, rather, as a way to off-load their existing dispatch channels.
Over time, other network operators became interested in PTT for their networks and tried various methods to compete with Nextel. CDMA network operators tried VoIP on the data channel and GSM networks tried various VoIP solutions, but these did not work well enough to satisfy their customers. The issue was one of time delay. From the time a customer pushes the PTT button to turn on the transmitter until they can begin speaking is called set-up time, and the time it takes from when they release the PTT button to turn off the transmitter so another user’s voice can be heard as they respond is called volley time. For comparison purposes, a true two-way radio network has a set-up and volley time of less than 100-300 milliseconds, and Nextel’s Direct Connect achieved a set-up time of less than a second with volley times in the 500 millisecond range. In contrast, VoIP systems, which were touted as being true PTT, had set-up times in the 4-8 second range and volley times in the 3-5 second range, making PTT communications with VoIP very frustrating.
In late 2003, Kodiak Networks launched a PTT technology that used existing wireless voice channels and was not based on VoIP. While the set-up time was a couple of seconds longer than Nextel’s, once a PTT session was set up, volley time was faster than Nextel’s system at 150 milliseconds. Thus was born the first real competitor to Nextel’s PTT. In the United States, AllTel was the first commercial CDMA network to deploy the Kodiak system and, at the same time, Kodiak PTT was launched by Orange, a European GSM operator. Then, in 2005, Cingular (now AT&T Wireless) deployed Kodiak’s nationwide PTT system.
When Cingular (AT&T) launched this PTT system, it was marketed by both its business-to-business sales organization to be sold directly into the Nextel installed base and by its consumer sales channel as well, because AT&T believed this type of one-to-many voice communications would appeal to teenage wireless customers who favor group communications, as demonstrated by their Instant Messaging usage. AT&T was right and many groups of teens now use PTT on a regular basis.
But the service AT&T deployed was not confined to PTT—it had other new voice capabilities as well. For example, it offers push-to-conference, a feature that enables a PTT session to be converted to a full-duplex conference call (where everyone can talk at once) with a single push of a button. My favorite is AT&T’s push-to-voice message, where I can select one person or group of people and, without ringing their phones, I can push out a voice mail to them that will show up in their voice mailbox.
For awhile, things in the PTT marketplace seemed to go quiet. When Nextel and Sprint merged, they announced plans to migrate their Nextel PTT customers to Sprint’s CDMA2000 1xEV-DO network using a technology developed by Qualcomm with input from both Nextel and Motorola (making it a proprietary solution only for use by other operators where Nextel’s iDEN technology was not deployed). The issues here are that the migration from Nextel to Sprint has been delayed for several reasons including a lawsuit between Broadcom and Qualcomm that directly impacts the use of the Q-Chat technology, and the slower than expected ability to migrate Nextel customers to the Sprint network.
PTT Evolves to Push-To-X (PTX)
Meanwhile, several vendors including Nextel realized that there are more ways than simply push-to-talk to add value to the most widely used technology in wireless—voice. When AT&T deployed its PTT service, it launched additional “push-to” voice services. Nextel countered with its own new push-to services and in February of this year, Sprint Nextel, in a effort to hang onto its PTT customers, introduced what is being termed Push-To-X services. What does this mean exactly? According to Nextel, this means it has launched a number of other push-to services including push-to-send voice mail and push-to-send pictures.
With push-to-email, Nextel users can send voice mail to someone’s email address by setting up the address and using the PTT button to send the message. With push-to-picture, customers can send pictures to compatible phones that also have direct send capability. Finally, there is push-to-contact, which enables users to send contact information from their address book to another Nextel device.
Well, AT&T was not sitting on the sidelines while Nextel was developing its push-to enhancements and it has come up with more PTX services. For example, AT&T’s PTX provides for converting a PTT session into a standard wireless call, push-to-voice message and push-to-conference as mentioned above, push-to-send contacts and groups and, using 3G MMS technology, push-to-email, push-to-video and push-to-picture.
This week, the competition grew more intense as Kodiak rolled out new applications that make using wireless voice and text even more user-friendly and productive. Some of these features will work on phones that do not require a separate client, so, in essence, they can be deployed on any phone and on any network. Kodiak introduced some new conferencing products that enable users to initiate or schedule a conference call directly from their handset. My favorite feature is designed for all of us who have tried to dial into conference calls from our cars, entered the call-in number, then the PIN and joined the call only to be dropped and have to enter everything all over again. SMS conference invitation enables users to join and rejoin conference calls with a single click. Now when I want to join a conference call, I can simply click on the dial-in number in the SMS message, my number is auto-authenticated in the background and I’m put into the bridge. With the SMS interface, I can also see a list of who is on the call.
Kodiak has added yet another important capability to its client-based and clientless group text and voice messaging applications. You can reply to a single message sender or reply to all of the message recipients directly from the original message.
The last product I’d like to mention is something we could all use: Quick Reach. Instead of calling someone’s mobile, then their office and maybe even their home to reach them, you can set up a contact profile that has all of an individual’s numbers saved. For example, I would create a profile for one of my partners called “Find Bob.” When I call “Find Bob,” all of his phone numbers ring simultaneously, and after the first of the phones is answered, the other calls are immediately disconnected.
With Nextel pushing its PTX services and Kodiak rolling out additional voice services that can be but don’t have to be tied to a specific client, things will be heating up in the PTT/PTX arena once again!
Andrew M. Seybold