AT&T: We're using WCS C, D Block spectrum for in-flight Wi-Fi because of interference concerns

In a new filing with the FCC, AT&T Mobility (NYSE: T) said that it doesn't believe it can use its WCS C and D Block spectrum for a mobile LTE network because the system would create too much interference with other operations in nearby spectrum bands. As a result, the carrier said it hopes to use the spectrum to provide in-flight Wi-Fi services because pointing the antennas up at the sky would reduce the possibility that the network would interfere with operations in adjacent bands, including Sirius XM radio.

AT&T's efforts in the 2.3 GHz WCS band started in June 2012, when it inked an agreement with Sirius XM to essentially create a 5 MHz guard band between Sirius XM's operations and the WCS band. Then, just a few months later, AT&T acquired more WCS spectrum from NextWave, for around $600 million. At the time, AT&T said it would use the WCS spectrum to improve its mobile LTE network.

In a filing this week with the FCC, AT&T said it has moved forward with plans to use the WCS A and B Blocks for its mobile LTE network. "Nevertheless, AT&T has continued to struggle to develop uses for its WCS C and D Block spectrum given the strict transmission limits to protect adjacent band operations from harmful interference," the carrier wrote. "AT&T now has found a way to put the C and D Block spectrum to productive use without infringing on its spectral neighbors." The carrier will use the spectrum to provide in-flight connectivity services, a plan it first announced in April.

"Not only will this in-flight connectivity service result in a robust, rapid and nationwide deployment of facilities using the WCS C and D Blocks, it will avoid the inference problems that have bedeviled past efforts to use this spectrum intensively," the carrier wrote. "Because base station antennas will tilt up, an air-to-ground service inherently will be less likely to interfere with Sirius XM receivers on the ground than a terrestrial application's downward-tilting base station antennas."

In order to begin building its in-flight broadband network, AT&T said it needs the FCC to change some of its WCS rules to allow for the service.

AT&T's filing provides more clarity on the carrier's plans to provide connectivity to airplanes. The carrier said that, late next year, it hopes to begin providing "robust, uninterrupted service" to all routes within the contiguous United States among 50 or more airports classified as large or medium hubs by the FAA. The carrier said the service would provide in-flight Wi-Fi to travelers as well as connection services to airlines for cockpit communications, maintenance operations and crew services. The carrier said ground-to-air transmissions should occur over the D Block while air-to-ground services should occur over the C Block.

AT&T's plans put it into direct competition with existing in-flight connectivity providers like Gogo, Row 44, Inmarsat and others.

Interestingly, those companies aren't standing still either. Gogo recently requested a "special temporary authorization" from the FCC to perform testing "in the 3650-3700 MHz band as well as the various 5 GHz ISM bands (including 5.725 to 5.825 GHz)." Gogo said the testing is intended to help it provide faster in-flight connection services, though the company didn't provide details of the tests in its filing.

For more:
- see this AT&T filing
- see this Gogo filing

Related Articles:
AT&T looking to buy all of Sprint's 2.3 GHz WCS spectrum licenses, possibly for in-flight Wi-Fi
AT&T targets Gogo, others with plan to launch in-flight LTE by 2015
AT&T scores AWS, 2.3 GHz WCS spectrum for LTE
AT&T to acquire NextWave--and its WCS spectrum--for $600M

Suggested Articles

The WBA is inviting all organizations in the Wi-Fi ecosystem to join WBA OpenRoaming and make Wi-Fi roaming better for everyone.

DSS will first be available in parts of AT&T’s network in North Texas.

NATE issued an advisory to its members Thursday about Global 5G Protest Day activities reportedly planned for this Saturday, June 6.