RLHOR: Reliability-aware location and history based opportunistic routing

Recently, routing in Vehicular Ad hoc Networks (VANETs) has found significant attention. Besides, since these networks are highly dynamic and their topologies change rapidly, design of routing algorithms suitable for an urban environment is extremely challenging. Appropriate algorithms for urban environments could be opportunistic routing algorithms in which traffic transmission from source vehicles to destination vehicles is performed using the store-carry and forward mechanism. Most of the existing opportunistic routing algorithms use the flooding mechanism for increasing delivery ratio without considering the overheads of flooding. Thus, in order to reduce the overhead in these methods and improve the performance of routing in VANET, choosing an appropriate node to send messages and determining priority of messages for transmission will be very important. An efficient opportunistic routing (OR) mechanism, called Reliability-Aware Location and History Based Opportunistic Routing (RLHOR) is proposed in this paper for improving overhead. The RLHOR searches for a stable path by evaluating the stability of intermediate links based on lifetime of links, location and direction of intermediate vehicles, and history of intermediate vehicles in message delivery. Using the ONE simulator, our performance evaluation results show that the RLHOR operates better than conventional opportunistic routing algorithms. The RLHOR not only increases delivery rate, but also reduces network overhead, traffic loss, and number of aborted messages in sparse scenario.