Enabling a Win-Win Coexistence Mechanism for WiFi and LTE in Unlicensed Bands

Abstract

The problem of WiFi and LTE coexistence has been significantly debated in the last years, with the emergence of LTE extensions enabling the utilization of unlicensed spectrum for carrier aggregation. Since the two technologies employ com-pletely different access protocols and frame transmission times, supporting coexistence with minimal modifications on existing protocols is not an easy task. Current solutions are often based on LTE unilateral adaptations, being LTE in unlicensed bands still under definition. In this paper, we demonstrate that it is possible to avoid a subordinated role for WiFi nodes, by simply equipping WiFi nodes with a sensing mechanism based on adaptive tunings of the ambient noise thresholds (as indeed considered by several commercial cards). Under this assumption, we propose a win-win coexistence mechanism between the two technologies, that does not require modifications on legacy WiFi access operations. We model the interactions between the two technologies in terms of a game and demonstrate the feasibility of the approach in simulation and in real experiments.