Application-value-awareness cross-layer MAC cooperative game for vehicular networks

Abstract

In vehicular ad-hoc networks (VANETs), numerous safety related applications have a stringent requirement for the upper latency limit for transmission of messages between vehicles. Thus, it is necessary to design a high-efficiency medium access control (MAC) method that can ensure the allowed upper limit of message delivery delay is satisfied. In this study, we propose the concept of application value (i.e., the value of a conveyed packet), and correlate it with the waiting time of a packet determined by the delay of each concerned message. Subsequently, we design an inter-vehicle cross-layer cooperative game model taking into account the global optimal utility of the participants. Next, we theoretically prove the existence of an equilibrium using a Markov decision process (MDP), and provide a concrete approach to obtain the channel access probability of a node according to the best response method. Finally, we present the results of a partially observable MDP (POMDP) and of the extensive numerical analyses of the performance indicators such as the access delay, throughput, and packet delivery rate (PDR). These are compared with the IEEE 802.11p protocol in saturated and unsaturated states. These comparisons show that the proposed cross-layer MAC cooperative game method guarantees the message transmission delay when the channel is nearly saturated, enabling a successful delivery of the messages within the time limit and providing a strong support to delay-sensitive safety related applications.