Performance Analysis of Random Access Strategies for Short Message Exchange in VANETs: A Social Approach

Major applications of Vehicular Ad Hoc Networks (VANETs) are strongly related with safety applications like emergency warning, rescue operations, information about road conditions and accident alert. However, little attention has been given to the design of comfort applications with social approach, such as the connecting of people with common interests (like twitter or SMS services). Most of the work reported in the literature in VANETs is focused on clustering and routing schemes for the dissemination of queries in the network, however, the impact of the media access control (MAC) protocols has been largely overlooked. In this work is studied the transmission of short messages and different MAC strategies for social network applications, to operate in VANETs and pedestrian environments, are proposed. Specifically, a comprehensive study of two main random access protocols: CSMA/CA and S-ALOHA and two of the most common back off algorithms: Uniform Back off (UB) and Binary Exponential Back off (BEB) is presented. As an additional feature, the proposal of a MAC hybrid strategy to improve the system performance in terms of the success probability and delay is developed.