AT&T Buys MediaFLO Spectrum

AT&T says it will use the spectrum for one-way delivery of content, which makes the most sense to me, and gives AT&T a leg up against its competition. LTE, 4G broadband is more efficient the more spectrum you have.

On October 19, 2010, an article I wrote about Qualcomm’s MediaFLO demise and what I thought it should do with the spectrum appeared in FierceWireless. My idea was for Qualcomm to wholesale its network to commercial network operators that could then reroute their customers’ larger data files and streaming video downloads over the FLO network, thus freeing up bandwidth on their own wireless broadband networks.

Instead, in a deal worth $1.925 billion, AT&T agreed to buy the spectrum licenses held by Qualcomm for the MediaFLO spectrum in two blocks in what is called the “lower 700-MHz band.” The original MediaFLO spectrum (replacing UHF TV channel 54) is 6 MHz of unpaired spectrum and Qualcomm’s licenses provide coverage to more than 300 million people. Later, Qualcomm went back to the auction block and bought an additional 6 MHz of spectrum in the top fifteen U.S. metropolitan areas. This spectrum covers an estimated 70 million people including those in New York, Boston, Philadelphia, Los Angeles, and San Francisco. This additional 6 MHz of unpaired spectrum is adjacent to the original spectrum AT&T purchased, giving it 12 full MHz of unpaired spectrum in these major metro areas.

This was a bold move by AT&T and while it has not announced specific plans for use of this spectrum AT&T stated that they would be it inot operaton after LTE Release 10, which adds support for multi-casting. This means that AT&T will be able to use this spectrum in a variety of ways, all different from how Qualcomm had deployed it. The MediaFLO system used very-high-power transmitters covering large areas, in some cases about the same power and coverage as a TV station would have. For example, the FLO system in Las Vegas consisted of three high-power transmitters located on mountaintops surrounding the city (Las Vegas sits in a bowl surrounded by mountains). Its signal for the mobile TV offering was great. Even inside most of the casinos and in the elevators, it was possible to receive the TV signal from the MediaFLO system.

AT&T has indicated that it only purchased the spectrum and not the Qualcomm system. To me this means AT&T is not interested in following this model for content distribution as it would require sending data streams over large areas simultaneously, which makes sense when you are delivering a number of TV channels to many different customers, but it does not make sense to use this same network topology if your goal is to be able to provide different data or different video streams to individuals or groups of people.

Therefore, my guess is that AT&T will design its system one of two ways:

It will remain an outbound-only system, tied into the LTE two-way network on 700 MHz, but built in a more cellular-type approach with many radio transmitters in a given area. This will enable the company to deliver more, large-content files to its customers than over its two-way LTE network. Further, AT&T could design the network to be used to download files, videos, and other large content on a scheduled basis. This would spread out the traffic load during the day and the company would still be able to deliver content on a real-time basis without affecting the loading on its two-way system. This makes the most sense to me, especially since Qualcomm is already building a 700-MHz receive-only chip that could be included in many different types of devices.

The second thing it could do is to build out the spectrum as a two-way system, using Time-Division-Duplex (TDD) technology instead of the much more traditional Frequency-Division Duplex (FDD), which is the most common way to build commercial networks. The Clear/Sprint WiMAX network uses TDD technology and LTE will support TDD. In fact, Qualcomm’s new LTE chipsets will support both FDD and TDD so they can be used in devices regardless of what technology the network operator has chosen. My opinion is that AT&T will not take this approach for a number of reasons. First, it would have to have wireless devices that supported both FDD and TDD in the same device, and I am not sure this is even possible although our wireless design engineers have become very good at doing the impossible. The second is that while it would give AT&T more capacity in both directions (to and from the wireless device), it would not be as effective a use of the spectrum as using it for one-way, heavier data delivery options.

AT&T says it will use the spectrum for one-way delivery of content, which makes the most sense to me, and gives AT&T a leg up against its competition. LTE, 4G broadband is more efficient the more spectrum you have. Verizon’s system is built out on 10X10 or 20 MHz of spectrum (although it does have some other LTE spectrum available in major markets). While AT&T’s system will be limited to 5X5 in many areas, it has 6X6 adjacent spectrum in major metro areas putting it on a par with Verizon. The difference is that now that it has 6 MHz and in some areas 12 MHz of spectrum it will use for download services, it will have an advantage over Verizon in some areas.

Wireless broadband is all about trying to meet the demand for broadband access—which is virtually impossible since demand will outstrip capacity in the next few years—but AT&T has found a solution that will provide an edge when downloading data and streaming video. It will still have to be careful with managing its spectrum, but this appears to be a good purchase on AT&T’s part.

It will be a few years before this spectrum is placed into service, but by then demand for wireless broadband services will have continued to expand and those offering broadband services will have to deal with the issue of providing their customers with the best possible experience. The FCC’s recent Net Neutrality ruling enables wireless operators to continue to manage their networks wisely and provide the best possible experience for all of their customer, but it does place some limitations on wireless operators which will make it harder for them truly manage their networks in an effective manner.  However, the rule of the day is still that those with the most spectrum will have an advantage over the other operators.

Andrew M. Seybold

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