Qualcomm Rips Latest Version of LTE-U/WiFi Test Plan

Qualcomm, Inc., today ripped the latest version of the Wi-Fi Alliance’s test plan to gauge coexistence between Wi-Fi and LTE-U operations, as the alliance held another workshop on the topic in San Jose, Calif. The alliance yesterday released version 0.8.6 of its test plan. The group has said it plans to release the final version, version 1.0, of the plan by the end of next month. Several sources said today said the plan released yesterday will undergo lab testing in the lab, known as a “plugfest,” which could result in changes before the final plan is issued. 

 “As of this writing, the tests within the test plan have not undergone validation for feasibility, correctness, or repeatability,” according to the 47-page version of the plan released yesterday. “It is therefore incomplete and cannot be used to determine LTE-U coexistence until approved in its entirety by the Wi-Fi Alliance board.”

“The latest version of the test plan released by the Wi-Fi Alliance lacks technical merit, is fundamentally biased against LTE-U, and rejects virtually all the input that Qualcomm provided for the last year, even on points that were not controversial,” said Dean Brenner, senior vice president-government affairs for the chip maker. “We saw that a Wi-Fi group yesterday called this new version of the plan a compromise.  In truth, we submitted a compromise proposal which the Wi-Fi Alliance rejected in its entirety and instead issued this plan, which has the clear purpose of trying to keep the benefits of LTE-U away from consumers and off the unlicensed spectrum, which is supposed to be for all of us.

 “The latest version of the plan would require LTE-U to protect Wi-Fi 100 times more than Wi-Fi would protect LTE-U in all environments under criteria that ignore data submitted to the Wi-Fi Alliance, including data from Wi-Fi vendors,” Mr. Brenner added. “Moreover, the plan is not based on any real, commercial Wi-Fi to Wi-Fi baseline, contrary to the WFA’s own guiding principles for this whole coexistence test plan effort.  Instead, it sets a bar for LTE-U that pretends that all Wi-Fi access points are made by a single vendor even using the same chipset and software release, in identical link conditions, communicating with a few cherry-picked Wi-Fi device models.” The statement added that “data we collected during the test validation process with the Wi-Fi Alliance staff, which we presented at today’s Wi-Fi Alliance workshop, shows that Wi-Fi access points, including some of the most popular Wi-Fi access points on the market today, do not share spectrum fairly with one another.  In addition, the plan even contains a test that has nothing to do with spectrum sharing at all and would convert an optional 3GPP feature into a mandatory requirement on an issue that literally has nothing to do with how LTE-U and Wi-Fi share spectrum.  Finally, the latest version of the test plan goes so far as to threaten to cover LAA as well in a future update, even though LAA has already completed a global standards process in 3GPP based upon input from all Wi-Fi stakeholders and even though 3GPP is establishing its own test plan for LAA.”

Mr. Brenner concluded “that the FCC should disregard this latest version of the plan, particularly because the watchword for unlicensed spectrum is supposed to be permission-less innovation, not incumbent protection.”

 In a statement today, the Wi-Fi Alliance said, “The final version of the test plan is still on track to be delivered in September. Any plans that have been released up until now aren’t the final version.” The group planned to release another statement following today’s workshop.

 Michael Calabrese, director of the Wireless Future Project at the New America Foundation’s Open Technology Institute, had mixed views on the plan. “Consumer advocates are heartened to hear the Wi-Fi Alliance has completed its LTE-U coexistence test plan.  However, it is alarming to hear that compromises on the test plan within this industry group could leave 50% of Wi-Fi connections at risk of disruption from LTE-U,” he said.

“It is also unfortunate that cellular industry proponents of using LTE on unlicensed spectrum are now threatening to pull back from Wi-Fi coexistence testing they initially proposed and supported,” he added.  “We call on the FCC to ensure that all implementations of unlicensed LTE devices pass the entire test and coexist fairly with Wi-Fi. The test results will help the FCC decide if LTE-U, which will be controlled from licensed spectrum bands, can coexist with Wi-Fi, the unlicensed technology that has proven critical to schools, consumers and the U.S. economy as it carries 80 percent of all mobile device data traffic.”

Yesterday, WifiForward hailed the release of the latest version of the test plan, and other cable entities have told the FCC that Wi-Fi proponents are willing to make “an extraordinary compromise” because the plan would leave “half of all outdoor Wi-Fi connections vulnerable to LTE-U degradation” (TRDaily, Aug. 2).

But Tom Sawanobori, senior vice president and chief technology officer of CTIA, said today, “Our member companies are eager to provide consumers with faster and more secure wireless services to meet their mobile-first lifestyles, so it is disappointing that cable continues to throw as many roadblocks as possible as evident by its push for unrealistic sharing arrangements.”

Other LTE-U proponents, including T-Mobile US, Inc., have complained about the length of time it has taken for the Wi-Fi Alliance to complete the test plan. For example, the carrier told the FCC recently that it should begin approving LTE-U devices beginning in October (TRDaily, Aug. 1). – Paul Kirby, paul.kirby@wolterskluwer.com

Courtesy TRDaily