Signal-to-interference-ratio based capacity analysis for vehicular ad hoc networks

Considering the different quality of service (QoS) requirements posed by the various applications of vehicular ad hoc networks (VANETs), the characteristic of communication capacity is vital for the design of the Intelligent Transportation System (ITS). Although some scaling law-based results had already been obtained for VANETs to describe the general performance changing pattern when the total number of network nodes goes to infinity, they cannot be used directly to estimate the actual capacity of a communication pair or the entire network. To make up with this disadvantage, a interference-based capacity analysis is finished in this paper for the VANET scenario. For representing the unique constrain of inter-vehicle distance, which directly affects both the signal and interference power decaying, the car-following model is used to describe the vehicles´ mobility feature. Based on that, a series of probability characteristics are derived for the worst interfered scenario, which finally leads to the expected VANET capacity. We believe the new results obtained in this paper will provide useful guidelines for the deployment of future VANETs.