Wi-Fi Alliance: August target for coexistence test plan with LTE-U could slip into September

Wireless operators and vendors looking to deploy LTE-U have expressed frustration in the past about the time it's taking to create a test plan for coexisting with Wi-Fi, and now it looks as though it might get pushed back a little more.

The Wi-Fi Alliance hosted another coexistence workshop last Wednesday in San Jose, California, where stakeholders were given status updates, including the expectation that a final test plan is likely to slip into September, according to Kevin Robinson, vice president of marketing at the Wi-Fi Alliance.

The various stakeholders, including LTE vendors, have expressed some concerns around the schedule, he acknowledged, and he asserted that the Wi-Fi Alliance heard and shared their desire to accelerate the pace of progress. "We are committed to delivering as quickly as possible on this test plan," he told FierceWirelessTech. "We're exploring every possible option" to accelerate the work while ensuring the objectives are met.

"Ultimately, we remain confident that Wi-Fi Alliance and the industry can and will deliver a solution in a timely manner," he said.

Among the big four operators in the U.S., Verizon (NYSE: VZ) and T-Mobile have expressed the most interest in deploying LTE-U. 

In response to a request for comment from FierceWirelessTech, Verizon today provided this statement: "We're disappointed by the Wi-Fi Alliance's lack of progress in finalizing its coexistence test plan. Despite the wireless industry's best efforts, the process is not working as we were led to believe."

A T-Mobile spokesperson said the company had no further comment beyond what CTO Neville Ray said during the company's first-quarter earnings call, when he expressed frustration in terms of not seeing the progress they would like to see with LTE-U. From the standpoint of getting solutions into the marketplace in 2016, the light is "dimming there a little" from a regulatory perspective, he said. LTE-U devices require FCC certification before they can be rolled out commercially.

The Wi-Fi Alliance Coexistence Task Group has been working to develop a plan to test LTE-U devices and ensure they don't interfere with Wi-Fi users. The Wi-Fi Alliance earlier this year said the goal was to deliver a coexistence test plan by summer 2016.

It's important to keep in mind it's a multi-industry effort being led by the Wi-Fi Alliance and something that hasn't ever really been attempted before, Robinson noted. Delivering coexistence for two different industries is no easy feat. Technical challenges exist and creating a testbed that can be reproduced in labs around the world is time consuming, and that's all playing out in the collaboration between Wi-Fi and LTE communities.

A lot of companies have been contributing to the efforts, he said. The primary driver of the schedule is the magnitude of the work involved in validating the test plan. Plugging in real devices and seeing how those devices interact and making sure the test case is repeatable are all part of the process.

According to Robinson, the stakeholders are looking at three levels of testing. There's consensus on two of those levels, but the third level is seeing rigorous debate and they have not yet reached consensus on that.

Back in March, Ericsson complained to the FCC that although the Wi-Fi Alliance final test plan was to have been established in January 2016, and then April, it would not be completed until mid-August at the earliest.

Update: After this article was published, the Wi-Fi Alliance pointed out that while the industry may have been pushing to get a plan in place, there wasn't an expectation that the test plan would be done in January.The industry first came together in late November and the first coexistence workshop took place in early February. 

Related articles:
Qualcomm gets green light to test LTE-U with T-Mobile
T-Mobile warns of delays on LTE-U as regulatory discussions continue
Wi-Fi Alliance says goal is to deliver LTE-U/Wi-Fi coexistence test plan by summer
Wi-Fi Alliance: Work on LTE-U testing regime ongoing, but it's unclear when it will be finished

Article updated June 27 to reflect Wi-Fi Alliance clarification about the timing of the planned rollout of the test plan.