Battle emerges over LTE-U and wifi coexistence

Major players from the North American telecoms industry have written to the FCC in staunch opposition of a recent Wi-Fi Alliance request for stringent testing on coexistence regulations between LTE-U and wifi devices.

It would appear as though a war is brewing between the wifi industry standards body, and operators and equipment vendors. The Wi-Fi Alliance recently wrote to the American communications regulator effectively demanding authority over the testing and approval of the use of unlicensed LTE spectrum (LTE-U). The standards body appeared to have concerns over a conflict where LTE devices and protocols may exist in the same spectrum frequencies traditionally reserved for domestic wifi. In its letter to the FCC, the Wi-Fi Alliance stated it needs to determine appropriate standards for LTE-U before the Commission can consider any regulations over its use.

“To advance the constructive collaboration that is required in order to potentially permit use of LTE-U technologies in unlicensed spectrum, and particularly in the 5 GHz band, WiFi Alliance is taking several significant actions in which it hopes the LTE-U Forum and equipment manufacturers will readily join,” it said. “First, we are developing a comprehensive coexistence test plan aimed at assessing the level of fair sharing between LTE-U and Wi-Fi for equipment supporting a range of applications. Second, we will work with LTE-U vendors as soon as possible to test their products to determine if they pass the Wi-Fi Alliance co-existence tests across all allowable configurations.”

It then went on to infer the only hold up will come from reluctance from LTE-U proponents.

“Of course, the success of these two steps will be dependent on collaboration with LTE-U product vendors, and so we are hopeful that they will fully participate in these testing efforts,” it said.

Verizon and T-Mobile, meanwhile, were cosignatories on a letter submitted to the FCC in response which argued that a dangerous precedent will be set if the standards body for one technology is given the right to impose limitations on another.

“Allowing an organization that certifies interoperability for one particular technology to become the gatekeeper for another technology to use unlicensed spectrum would jeopardize the Commission’s entire framework that has made unlicensed spectrum so successful as an open platform for permissionless innovation,” it said.

Verizon, T-Mobile, Alcatel-Lucent, Ericsson and Qualcomm, all of whom are members of the Wi-Fi Alliance, then claimed the Alliance ignored invitations for collaborative testing of LTE-U and wifi coexistence before it wrote directly to the FCC. They then stated the Wi-Fi Alliance didn’t consult with any of the five organisations regarding its own testing, laying claim to further self-interest and bias in the outcome.

“The LTE-U Forum gave a second all-day technical briefing to the Wi-Fi Alliance and twenty eight other associations and companies,” it said. “Both workshops included extensive technical presentations, robust question-and-answer sessions, and live LTE-U/Wi-Fi coexistence demonstrations in Qualcomm’s test-lab. In fact, immediately after these workshops Qualcomm invited the Wi-Fi Alliance to do their own LTE-U/Wi-Fi testing in Qualcomm’s lab. Qualcomm had previously made a similar offer to others in the WiFi community. These offers were not accepted.

“Instead, the Wi-Fi Alliance—three months later—filed its August 14 letter announcing its own initial workshop on coexistence in early November and plans for its own coexistence evaluation program. Although we belong to the Wi-Fi Alliance, they did not approach us or seek our input on this proposal; rather, we learned about its announcement when the Alliance filed its letter.”