July 9, 2015 — There is still trouble in the unlicensed LTE (LTE-U) camp. So far, LTE-U testing results indicate mixed results as to its ability to co-exist fairly with Wi-Fi. Mixed results may mean different things to different people, but the fact that there is controversy and technical issues is enough to infuse some doubt into the technology.
Granted the tests “favor” the testers — Google, Qualcomm and Broadcom — but the fact remains that there are co-existence issues, even if they are under unique or unusual conditions. Often times such conditions can become the norm as the proliferation of integrated networks proceeds. If LTE-U and Wi-Fi do interfere with each other, even at the edge, not doing something about it is asking for trouble.
And, along with its Wi-Fi issues, the LTE-U specifications developed by the industry consortium LTE-U Forum and the version being standardized by 3GPP, Licensed Assisted Access (LAA), are substantially different, because of requirements that differ from region to region.
The best scenario is that egos get put aside and unbiased tests show the real situation. It shouldn’t be a marketing or market share issue. There is plenty of room for both Wi-Fi and LTE-U.
Next there is LTE Wi-Fi link aggregation, known as LWA, whick is a way for carriers to integrate Wi-Fi and cellular. LWA uses LTE for the uplink and both LTE and Wi-Fi for the downlink. It requires a software update for devices so they can engage their Wi-Fi radios to handle some LTE traffic, which is collected at Wi-Fi access points and then sent to an LTE small cell. It also allows integration of LTE and Wi-Fi in the RAN because the system can optimize the way traffic is split between the two interfaces.
So far, there isn’t a lot of traction for LWA but there should be. Wi-Fi is taking an ever-increasing share of the mobile traffic. Once it expands to include voice calls, operators should integrate Wi-Fi with their core networks, and LWA is an ideal vehicle for this. That opens the possibility that carriers could eventually bill subscribers for time spent on partner Wi-Fi networks. So finally, a business case for Wi-Fi?