An enhanced connectivity aware routing protocol for vehicular ad hoc networks

Abstract

Vehicular Ad Hoc Network (VANET) is a self organized and self maintained communication network that is spontaneously and wirelessly formed by moving vehicles to provide safety, entertainment and information to its users. To tap these benefits, efficient and reliable routing protocols are needed. Designing routing protocol in VANET is challenging as the result of high vehicles’ mobility that result in frequent network disconnections. This is why existing routing protocols include route error handling to cater for the disconnection problem. Most of these solutions are variations of keep and carry strategy with or without a feedback mechanism to the source node. These strategies are sometime unnecessarily prolong the packet delivery and worst even if they failed, a new path discovery process is re-launched and that create more control overhead that waste the useful bandwidth. Even with Preferred Group Broadcast re-initiating route request creates additional control overhead. In this research, an Enhanced Connectivity aware routing (ECAR) protocol is proposed. The protocol utilizes an alternative backup route anytime the primary route to destination fails. It also uses control broadcast to further reduce the number of broadcasts needed to find routes to destination by allowing only the furthest node that receives a route request packet to rebroadcast it further in the network. NS2 simulation experimental results show that the performance of ECAR protocol outperformed the original connectivity aware routing (CAR) protocol by reducing the average packet delay by 28%, control overheads by 27% and increased the packet delivery ratio by 22%.