AT&T does an about-face, will support 700 MHz interoperability

AT&T promises to modify LTE network to Band Class 12, will work with chipset companies to add Band Class 12 to devices
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In a surprising move, AT&T (NYSE:T) said it supports 700 MHz interoperability and will begin adding Band 12-capable devices to its portfolio. Until this point, the company had adamantly refused to support Band 12, saying that it was unnecessary and would add costs to its devices.

In a blog post from Joan Marsh, the company's vice president of federal regulatory, she said that the company "has committed to investing considerable time and resources to the modification of its 700 MHz LTE network through the implementation of a newly-standardized software feature. That effort will allow AT&T's network to support Band 12 capable devices." She also said the carrier will work with chipset partners and OEMs to add Band Class 12-capable devices to its portfolio.

In a filing with the FCC, AT&T provided some additional details about the modification to its network. Specifically, the company said it must develop, implement and deploy throughout its network multi-frequency band indicator, or MFBI, capabilities that will let its network operate simultaneously in both Band 12 and Band 17 and support devices in both bands. The feature was recently standardized but will require lab testing and field testing, the carrier said. The field testing will have to use existing Band 17 legacy devices with carrier aggregation capabilities operating with the MFBI feature. 

In addition, AT&T will have to field test the MFBI feature with Band 12 devices, which it cannot do until deployment is complete. The operator also said that since it does not own any 700 MHz A Block licenses it cannot test Band 12-capable devices on the A Block network. Instead, it will have to test it on the 700 MHz Lower B and C block spectrum. The company did not provide a time frame for how long this deployment and testing would take. 

AT&T's decision will be a big boost to Lower A Block licensees such as C Spire Wireless and U.S. Cellular (NYSE:USM), which have argued that they could not use all of their Lower A Block 700 MHz spectrum because equipment makers would not make devices to support Band Class 12 without having commitments from larger Tier 1 operators. C Spire and others argued that OEMs like Apple (NASDAQ:AAPL) will make equipment for AT&T's Band Class 17 and Verizon Wireless' (NYSE:VZ) spectrum in Band Class 13, but not for those smaller companies that hold 700 MHz A Block spectrum in Band Class 12.

The about-face by AT&T is also a big win for Acting FCC Chairwoman Mignon Clyburn. Since March 2012, the FCC has been pondering a proposed rulemaking that would promote interoperability in the Lower 700 MHz band, and the issue has been kicked around in the wireless industry for almost four years.

In a statement, Clyburn said: "After many frustrating years, wireless carriers have finally reached a voluntary industry solution that will resolve the lack of interoperability in the Lower 700 MHz band in the most efficient manner. This is a big win for consumers, especially in rural areas, who will see more competition and more choices."

The Competitive Carriers' Association, which worked with operators such as C Spire and U.S. Cellular on 700 MHz interoperability, praised Clyburn for her efforts. "Chairwoman Clyburn was willing to roll up her sleeves and get in the middle of dispute between carriers that had escaped resolution for over four years, until today," said CCA President and CEO Steve Berry.

For more:
- see this AT&T blog post
- see this FCC statement
- see this FCC filing

Related Articles:
Apple opposed to strict FCC 700 MHz interoperability mandate
AT&T: We're committed to finding 700 MHz interoperability solution
U.S. Cellular spectrum partner bewails absence of Band 12 in Apple's iPhone
Lower 700 MHz A Block licensees gain more time to build networks
Entner: Forcing 700 MHz A-Block interoperability is not the answer
Execs: 700 MHz interoperability will unleash investment, jobs
AT&T: 700 MHz interoperability proposal unnecessary, unprecedented
Qualcomm at work on chip to support multiple 700 MHz bands

Article updated Sept. 11 to include more details on the changes AT&T must make to its network and the testing that must happen to ensure the interoperability is working.