AT&T, Qualcomm demo carrier aggregation technology for the FCC

As the FCC mulls AT&T's (NYSE:T) proposed $1.93-billion acquisition of Qualcomm's (NASDAQ:QCOM) 700 MHz spectrum Qualcomm had used for its now-defunct MediaFLO mobile TV effort, representatives from the FCC, Qualcomm and AT&T visited AT&T's Innovation Center in Washington, D.C. to witness a demonstration of carrier aggregation technology, which AT&T plans to deploy in the MediaFLO spectrum.

Carrier aggregation technology will essentially allow AT&T to meld together the unpaired MediaFLO spectrum with its existing AWS, 1900 MHz or 850 MHz spectrum holdings to double the downlink speeds of its planned LTE network. Interference problems preclude the operator from bonding Qualcomm's spectrum with AT&T's lower 700 MHz B- and C-block spectrum. Carrier aggregation is a key element in the specifications for LTE Advanced, WiMAX 2 and future iterations of HSPA+.

In an ex parte filing with the FCC, Qualcomm said its demonstration of carrier aggregation technology showed that when the channel sized jumped from 5 MHz to 10 MHz, the multicarrier channel not surprisingly supported more users and faster downloads. The demonstration used  2 x 5 MHz of AWS-1 paired spectrum and 5 MHz of unpaired spectrum at 1.4 GHz.

If AT&T scores access to Qualcomm's spectrum, and if its attempt at carrier aggregation is successful, the move could give AT&T the upper hand in the battle for the fastest data speeds quite early in the LTE game. (AT&T has said it plans to launch LTE this year, and will cover around 70 million people with LTE by year-end.) For example, if 10 MHz of the Qualcomm spectrum is added to a 10 MHz downlink on the LTE network, the network could experience slightly more than a two-fold increase in the capacity available, AT&T pointed out in an earlier FCC filing that the carrier submitted before it announced plans to acquire T-Mobile USA for $39 billion.

"As a result, AT&T will be able to handle a far larger number of customers using mobile broadband services," AT&T wrote in the filing. "Also, user data speeds will increase since peak data rates increase linearly with the bandwidth of the carriers deployed. Thus, where downlink capacity is doubled from 10 MHz to 20 MHz, customers may experience a doubling of peak speed."

In the FCC filing, AT&T said it plans to move aggressively to integrate MediaFLO spectrum into its LTE network if the FCC approves the transaction and after the relevant 3GPP standards are released. While the LTE Advanced standard is expected to be released at the end of this year, the performance requirement specs for each individual carrier supplement downlink scenario need to be developed by the 3GPP. After the standards are released, vendors would need to build the necessary equipment for the MediaFLO spectrum blocks. As such, AT&T estimates it could deploy handsets with carrier aggregation technology as early as 2014.

Interestingly, Qualcomm also pointed out in its demonstration that while the eventual deployment of carrier aggregation technology on the Qualcomm spectrum will be highly beneficial for consumers, it will not solve the spectrum crunch. "Resolving the spectrum crisis will require the allocation of substantial amounts of additional spectrum for commercial mobile wireless services, as indicated in the Commission's National Broadband Plan," the company said.

The comment is interesting in light of the fact that AT&T is pushing hard for its proposed acquisition of T-Mobile USA. The rationale for that acquisition is the solve AT&T's spectrum crunch.

Qualcomm could not comment on the filing by press time.

For more:
- see this ex parte filing

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