A Delay Sensitive Bus-based Routing Technique for Urban Vehicular Networks

Vehicular Ad Hoc Networks (VANETs) allow the share of various sorts of information between vehicles in a collaborative way. High delivery ratio and low latency are two main objectives of VANET routing schemes. Unlike other types of vehicles, Public Buses (PB)s that constitute the Bus Rapid Transit system have wide coverage, fixed routes, and regular services. Inspired by these unique features, several bus-based backbone protocols have been proposed. In this paper, we present an enhanced version of the Bus-based Routing Technique (BRT). BRT uses a learning process to determine the required time (the temporal distance) for each data transmission to RoadSide-Unit (RSU)s. As a routing strategy, BRT nodes (buses) use the previously learned temporal distances as a metric when selecting the next-hop. In the absence of a better candidate toward the destination, nodes switch into the store and forward DTN mechanism. In this work, we present a new variant of BRT that we call the Delay Sensitive Bus-based Routing Technique (DSBRT). Our technique suggests an enhanced learning process to optimize the latency. The performance of BRT and DS-BRT has been evaluated using the network simulator NS-2 and SUMO. The simulation results show that our improved BRT version outperforms BRT in terms of end-to-end delay and packet delivery ratio.