Wi-Fi Alliance: Work on LTE-U testing regime ongoing, but it's unclear when it will be finished

LAS VEGAS -- A top executive from the Wi-Fi Alliance said the group is making progress in its efforts to create a testing regime for LTE-U technologies, with the goal of creating some common ground between the Wi-Fi industry and the cellular industry over the controversial technology. However, he said it's not yet clear when the association would finish its work and actually release a testing process for LTE-U; he said the group might announce a due date for that work during its upcoming meeting in February.

"We are working on the test regime now," said Kevin Robinson, VP of marketing for the Wi-Fi Alliance, noting that stakeholders in the proceeding are having weekly meetings on the topic. "There is absolute alignment [in the technology industry] in determining a test regime [for LTE-U technology] and that the work would be done within the Wi-Fi Alliance… We're the forum where they can have these difficult technical discussions."

Importantly, Robinson also provided an outline of what the testing regime will look like for LTE-U. He said the association is working on three main elements for the testing regime:

1.      Basic scenarios: Robinson said work on this portion of the regime is almost done, and that it would cover the basic process to test one Wi-Fi device and one LTE-U device that are nearby and using the same spectrum and network.

2.      Low-energy detection scenarios. Robinson said this testing will look at the connection strength of various Wi-Fi and LTE-U devices, and determine how they will work alongside each other in various stages of weak signal strength.

3.      Complicated scenarios. Robinson said the Wi-Fi Alliance will also create a testing paradigm for more complex situations where Wi-Fi and LTE-U devices might encounter each other, like densely packed sports stadiums and other high-traffic areas. Robinson made his comments here on the sidelines of the CES event, and noted that the Las Vegas Convention Center at the height of the CES show is an ideal example of the complicated scenarios the testing regime will cover. "Those are difficult tests to write and conduct," he acknowledged.

Robinson said the goal of the testing regime, once complete, will be to determine whether there is "fair sharing" between Wi-Fi and LTE users in the same spectrum. He described "fair sharing" as whether one LTE user entering unlicensed spectrum would have "no worse impact" on an existing Wi-Fi user in that spectrum than would the addition of another Wi-Fi user.

To be clear, the testing regime is only the first step in a long process toward smoothing the disagreements between the Wi-Fi industry and the cellular industry over LTE-U, LAA and other such technologies designed to transmit LTE signals in unlicensed spectrum. Instead, the testing regime is only intended to create a common ground for discussions about the potential commercial rollout of LTE-U technology. So far, Robinson explained, some Wi-Fi proponents have cited testing result that they say show harmful interference from LTE-U technologies. Meantime, LTE-U proponents have cited their own tests showing the opposite. Thus, the Wi-Fi Alliance's testing regime, once it is complete, is intended to allow industry players to conduct standardized tests on various LTE-U technologies to see if they do or do not impact Wi-Fi users.

LTE-U proponents last year initially rejected the Wi-Fi Alliance's Co-Existence Evaluation Program for developing a comprehensive coexistence test plan. However, after a November workshop sponsored by the Wi-Fi Alliance that brought together about 100 people from 54 different companies, players ranging from Verizon to Google agreed on the need for additional clarity in the LTE-U specification, as well as broader testing and a commitment from stakeholders to collaborate.

The issue is critical to some wireless carriers: Verizon and T-Mobile have expressed a desire to roll out LTE-U in 2016, and AT&T, Verizon and T-Mobile are among the members of Evolve, a coalition launched in September to promote the benefits of unlicensed spectrum and new technologies like LTE-U and License Assisted Access (LAA). LAA is being developed as a standard through 3GPP.

The Wi-Fi Alliance plans its next invitation-only workshop on Feb. 10 in San Jose, and Robinson said at that time the group expects to announce when it will complete its testing regime.

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