T-Mobile makes case for LAA in 3.5 GHz band

T-Mobile US (NYSE:TMUS) wants to make sure the FCC knows the benefits of using Licensed Assisted Access (LAA) technology in, among others, the 3.5 GHz band, saying it's compatible with Wi-Fi and should be considered as the FCC adopts rules for the 3.5 GHz band.

T-Mobile representatives met via phone with members of the FCC's Office of Engineering and Technology staff to urge the commission to adopt rules that are "sufficiently flexible" to accommodate a range of technology platforms, according to an ex parte filing.

T-Mobile announced during Mobile World Congress 2015 that it was teaming up with Qualcomm Technologies (NASDAQ:QCOM) and Alcatel-Lucent (NYSE: ALU) to use LTE in the unlicensed 5 GHz spectrum. Trials are expected to begin this year using LTE-Unlicensed technology, a pre-standard version of the technology.

Earlier this year, T-Mobile and Ericsson (NASDAQ: ERIC) explained that they want to use LAA to make data transmissions in the underused 5 GHz band more efficient while continuing to provide a high level of service. They also promised to share the spectrum fairly with Wi-Fi users.

Neville Ray, EVP and CTO of T-Mobile US, has said that the 5 GHz band is where the most energy is focused and that's where the first solutions will be, but any unlicensed band is open to LTE.

In a presentation titled "Promoting Innovation in the 3.5 GHz Band," T-Mobile makes the case for the FCC to remain flexible in its rules for the 3.5 GHz band, arguing that with respect to LAA in particular, "no additional regulation is necessary" because in many cases, it will be a better neighbor than other General Authorized Access (GAA) technologies.

T-Mobile also said Wi-Fi will continue to be an important technology for carriers for the foreseeable future. T-Mobile has a long history of using unlicensed spectrum. Today, it has 20.5 million customers on its network with Wi-Fi calling capabilities, and nearly 5 million T-Mobile customers use Wi-Fi calling each month. Plus, it handles an average of 6.6 million Wi-Fi-originated calls each day, according to its presentation.

The "uncarrier" isn't  the only one weighing in on the 3.5 GHz proceeding. The New America's Open Technology Institute (OTI) and Public Knowledge (PK) met separately with FCC staff last week. They reiterated their support for an order that ensures a majority of the 3550-3700 MHz band is reserved for GAA and that also permits opportunistic access to Priority Access License (PAL) spectrum until "such time as the licensee reports to the Spectrum Access System (SAS) that it is commencing actual service."

They also expressed concerns about reports that companies, including Qualcomm and Verizon (NYSE: VZ), may be testing pre-certification versions of LTE-U that could be used by licensed operators on the 3.5 GHz to dominate GAA or other unlicensed spectrum users.

OTI and PK said they're concerned that, as noted by other stakeholders, Qualcomm's LAA could potentially crowd out or create consistent interference with other standards such as Wi-Fi that use contention-based protocols such as "listen before talk" to share unlicensed spectrum.

"Although Qualcomm has indicated this technology is most likely to be deployed by carriers in the 5 GHz unlicensed bands, it could readily be used by licensed carriers in the 3.5 GHz band," their filing said.

For more:
- see this FCC filing
- see this New America/Public Knowledge filing

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