A Game-Theoretic Framework for Coexistence of WiFi and Cellular Networks in the 6-GHz Unlicensed Spectrum

Abstract: We study the interaction of WiFi and 5G cellular networks as they exploit the recently unlocked 6-GHz spectrum for unlicensed access while conforming to the constraints imposed by the incumbent users. We derive the theoretical performance metrics for users of each radio access technology using stochastic geometry, thereby capturing the aggregate behaviour of the network. We propose a framework where the portions of cellular and WiFi networks are grouped to form entities that interact to satisfy their QoS demands by playing a non-cooperative game. The action of an entity corresponds to the fraction of its network elements operating in the 6-GHz band. Due to the decentralized nature of the game, we find the solution using distributed Best Response Algorithm, which improves the average datarate by 11.37% and 18.59% for cellular and WiFi networks, respectively. The results demonstrate how the system parameters affect the performance of a network at equilibrium and highlight the throughput gains as a result of using the 6-GHz bands. We tested our framework on a real-world setup with actual network locations, showing that practical implementation of multi-entity spectrum sharing is feasible even when the spatial distribution of the network and users are non-homogeneous.