Optimization and non-cooperative game of anonymity updating in vehicular networks

In vehicular ad-hoc networks, a large number of vehicles in mix-zones can increase privacy but at the expense of losing communication quality. Thus, it is necessary to harmonize these two conflicting goals for privacy protection. In this study, we propose an internal optimization model and an external anonymity updating game to cross-layer joint the physical layers transmit power and MAC layers delay into a two-step non-cooperative game model, by which the communication and privacy players respectively enjoy one utility function. The first step is to establish an internal optimal model aiming to balance privacy and delay, where we can obtain the optimal transmit power. The optimal number of neighbor vehicles can be obtained by selecting the transmitting power, which can be used as the input of the second step. For the second step, we present a non-cooperative external anonymity updating game model to analyze the non-cooperative behavior of vehicles, all of which together strive to maximize the utility function at the minimum cost. We analyze the Nash equilibrium in n-player complete information game, we also derive the pure strategy Nash equilibrium. Extensive numerical calculations are conducted to comprehensively investigate the reaction of the Nash equilibrium to various combinations of parameters. The results show that the two-step non-cooperative game of anonymity updating is capable of self-adapting to the vehicular context and improving the privacy without compromising on communication quality. (C) 2019 Published by Elsevier B.V.