Gateway Selection Game in Cyber-Physical Systems

Cyber-Physical Systems (CPSs) obtain the information of the physical world and impact the environment through many different kinds of devices. Usually, devices with different wireless technologies communicate with each other and the external networks through gateways placed in the working area. Different kinds of devices in a CPS may not operate with each other for their own benefit, and the competition will be more intense between different kinds of devices. They will contend for bandwidth of gateways to increase their throughput and avoid transmission delay. In this paper, we formulate this gateway selection situation as a noncooperative game. We investigate the actions of devices when they change their gateway and the result of devices' competition. We first give a bandwidth allocation model of gateways and propose a distributed algorithm for clients of gateway selection in order to increase the total bandwidth of their own kind. Then we investigate the migration trends of clients, and three theorems about the condition when clients stop migrating are given. We propose examples of gateway selection game with and without Nash Equilibrium. At last section, we give simulation results of gateway selection game.