With multiple wireless operators pursuing voice over Wi-Fi as well as the ongoing, often-heated debate over using LTE in unlicensed spectrum, 2016 will see the relationship between Wi-Fi and LTE continue to tighten. For LTE-U in particular, the year holds emergence of finalized standards, trials and even actual deployments of LTE over unlicensed spectrum in various forms. Here are three key developments to watch in 2016 for LTE-U.
Multiple LTE-over-unlicensed strategies
Mike Schabel, VP of small cells for Alcatel Lucent, noted there are three possible approaches for leveraging Wi-Fi as part of an LTE network. The two most commonly discussed are license-assisted access, which is being finalized for LTE Release 13 in early 2016 and includes “listen-before-talk” as a mechanism for coexistence with Wi-Fi; and the LTE-U Forum’s LTE-U spec, for North America and other regions where LBT is not required. LTE-U relies on Qualcomm’s carrier sensing adaptive technology and duty cycling for coexistence.
A third option that would allow carriers to utilize existing Wi-Fi nodes (with a software update), run Wi-Fi in unlicensed spectrum and LTE in a licensed band and aggregate the two. This approach is called LTE Wi-Fi aggregation and is also expected to be part of the finalized Release 13. Ruckus Wireless, for one, has called LWA “potentially the best of both worlds,” and Alcatel-Lucent demonstrated the technology at last year’s Mobile World Congress event with Qualcomm’s Snapdragon 820 chipset.
Continued testing and scrutiny of the technology in the lab and field
Verizon Communications’ CFO Fran Shammo told investors on the company’s third-quarter results call the carrier was lab-testing LTE-U and expected to deploy in 2016. As LTE-U moved into trials and deployments, commercial equipment will become more widely available for testing purposes by organizations such as CableLabs, which has been very focused on LTE-U/Wi-Fi coexistence testing.
However, the contention over whether LTE-U coexists fairly with Wi-Fi is expected to continue as well, as mobile operators, cable operators and players such as Google keep a watchful eye on one another and on the performance of LTE-U under various lab and field conditions. Bloomberg recently reported lobbying efforts are continuing. Some Wi-Fi proponents have made clear they wish to see LTE-U work through a formal, collaborative standards process – and the LTE-U Forum has made some efforts to concerns, but on its own terms.
The Wi-Fi Alliance has taken the lead in bringing together its members (including LTE-U Forum participants) and trying to coordinate communications as well as establish testing procedures to determine coexistence fairness. An initial workshop has already been held, and the LTE-U Forum specification updated in late 2015; that work is sure to continue in 2016.
Will federal regulators step in?Â
Looming over the LTE-U debate, of course, is whether the Federal Communications Commission will decide to intervene in any fashion. So far, the FCC has been content to gather information and comments, and observe the industry tussle over LTE-U. If coexistence proves out successfully in 2016, that may continue – but if Wi-Fi vendors can prove a consistent, significant, negative impact to unlicensed spectrum, it could be enough to prompt the FCC to take action.
