An Efficient Routing Protocol in a Bus-Based Vehicular Ad Hoc Network

Routing is one of the most challenging open problems in Vehicular Ad hoc NETworks (VANETs) because of the short-lived wireless connectivity environment. Store-carry-and-forward approach using buses on regular routes is considered as one of the most promising emerging routing policy that can significantly improve delivery performance and reliability in VANETs. While none of existing solutions considers the option of buses rather than only focus on forwarding data to any bus. Consideration on bus routes' non-uniform distribution in VANETs, we propose to use the Expected Min-Max Delay (EMMD) as a new select relay node metric in VANETs, and develop the optimized select relay nodes protocol (OSRP) based on the metric to forward data between buses. Simulations show the effectiveness of our method that it has similar delivery ratio and delay to the Epidemic routing, but can significantly reduce the data forwarding cost measured by the number of relays used.