Fairness vs. Performance in Rel-13 LTE Licensed Assisted Access

Wireless spectrum being a valuable resource, a large number of both non-profit and for-profit users rely on its unlicensed parts, usually to provide some sort of local area wireless coverage. When the cellular vendors and service providers expressed interest in the unlicensed spectrum, the incumbent community started to fear that the new technology would not respect the existing users. And although members of the incumbent community strongly influenced the design of licensed assisted access (LAA) in 3GPP, the fear has not dispersed yet. Representing a vendor with stakes in both communities, we attempt to disperse the fear by providing insight on the question of fairness and performance of LAA, openly discussing why it should generate less interference than WiFi and why it could be otherwise. We augment the discussion with insightful simulations, looking how detailed parameters of the channel access mechanism influence LAA's fairness and performance. Our investigations show that in common scenarios LAA is a fair neighbor to WiFi as is, and even in an extreme scenario only small adjustments to the channel access mechanism are needed to achieve the same outcome.