Verizon, T-Mobile reviewing LTE-U/Wi-Fi coexistence test plan

The two U.S. operators that have expressed the most interest in deploying LTE-U technology in unlicensed spectrum – Verizon and T-Mobile US – said they’re reviewing the details of the Wi-Fi Alliance’s final coexistence test plan that was released yesterday. They didn't say when they might be able to commercially deploy LTE-U.

“We’re pleased to be moving forward toward putting this important new technology to work for the benefit of customers,” Steve Sharkey, vice president of government affairs at T-Mobile, said in a statement. “There is still significant work to be done, and we are reviewing the details of the Wi-Fi Alliance’s LTE-U coexistence test plan.”

“Verizon is pleased that the Wi-Fi Alliance process has come to an end,” a spokesperson said in a statement. “After more than a year in the making, we look forward to reviewing the final details of their coexistence test plan. We are eager to deploy LTE-U and bring the benefits of this new technology to our customers. We are also pleased that the Wi-Fi Alliance has decided not to extend its test plan to other unlicensed technologies, such as LAA. It is important that unlicensed spectrum remain an open platform for innovation.”

Prior to yesterday’s release of the final coexistence test plan, Verizon called a draft plan “fundamentally unfair and biased” and told the FCC that it proposed an unrealistic and inaccurate Wi-Fi interference baseline. Referring to an earlier version of the plan, Qualcomm also said it lacked technical merit and was fundamentally biased against LTE-U.

But stakeholders continued to work on the test plan, apparently up until the last minute. And as recently as last week, Qualcomm representatives, including engineers Mingxi Fan and Durga Malladi, met with FCC Chairman Tom Wheeler’s legal advisor, Edward Smith, along with the FCC’s Chief of the Office of Engineering and Technology Julius Knapp, to discuss the progress they were making in reaching a compromise.

They told the commission (PDF) that Qualcomm developed the LTE-U, LAA and MulteFire technologies to provide better mobile broadband for consumers while ensuring from the outset that these technologies fairly share the U-NII-1 and U-NII-3 portions of the 5 GHz band, while not having an adverse impact on Wi-Fi.

Qualcomm declined to comment directly on the final test plan this week, referring to other stakeholders such as Evolve, whose members include Qualcomm, AT&T, T-Mobile, Verizon, CTIA, Nokia, Ericsson and the Competitive Carriers Association (CCA).

Shawn Change, spokesman for Evolve, released this statement: “The EVOLVE Coalition members are reviewing the details of the Wi-Fi Alliance coexistence test plan. It’s important that the details support a fair coexistence baseline and a clear path forward for LTE-U devices, and that LAA not be subject to this process at all.” LAA is the version being developed through the 3GPP standards process.

Details surrounding the test plan were still being hammered out in a workshop on Tuesday, where stakeholders in both the Wi-Fi and LTE communities continued to work on a way to include a multi-vendor benchmarking system that all the parties could live with, according to Kevin Robinson, vice president of marketing for the Wi-Fi Alliance.

In the end, “nobody gets everything they want,” in the final coexistence test plan, Robinson told FierceWirelessTech, but making compromises was the only way the industry was going to get a plan in place. All of the companies involved spent a lot of time and effort over the past year to get to the final plan.

The Wi-Fi Alliance is proud that it was able to lead the industry to a plan in the timeframe it did – these types of things typically take about twice as long. And other proposals during the process had real merit but they did not end up in the final plan, Robinson said. Ultimately, the industry was able to deliver a test plan that will provide assurances that LTE will share fairly with Wi-Fi, and there’s no need for regulators to step in, which was a threat that motivated industry to get moving on a compromise in the first place.

WifiForward, whose partners include Google, Broadcom and Boingo Wireless, applauded the Wi-Fi Alliance for developing the plan. “Measuring LTE-U devices for fair coexistence under the test plan is also crucial to protecting the major financial investments made by organizational Wi-Fi users from schools, hospitals and libraries to cities, governments and small businesses,” WifiForward said. “Only by requiring LTE-U equipment vendors to test all proposed devices according to the clear, consistent and comprehensive standards of the test plan can consumers have confidence that their Wi-Fi will continue to work as designed."

NCTA, which represents cable companies, said the final test plan represents a year of hard work by the Wi-Fi Alliance and by a diverse group of industry stakeholders, all of whom made significant compromises to reach a final result “based on sound engineering principles.”

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