A Beaconing-Based Opportunistic Service Discovery Protocol for Vehicular Networks

In the future, wireless access in vehicular environments (WAVE) will provide the foundation for a broad range of intelligent applications in transport, related to safety, comfort and, traffic management, to mention a few. Opportunities to instantaneously advertise and disseminate services arise with the technological advances of the vehicular networks. Points of interest (POI) to drivers and passengers, e.g, shops and gas stations, will broadcast advertisements with local services and facilities to the nearby vehicles by exploiting the road-side unit (RSU) infrastructure and comfort applications. However, RSU access coverage limitation or packet losses can prevent users (drivers or passengers) who are genuinely interested in services from finding them, even with a short distance from the POI. To improve the service discovery, we propose OSDP (opportunistic service discovery protocol), a protocol based on opportunistic vehicle contact and a store-and-forward technique to discover and advertise services in vehicular networks. OSDP is a lightweight and alternative protocol intended for location-aware applications. It supports distributed services fully independent from Internet access. In this paper we describe the key design concepts of OSDP and demonstrate its feasibility by a concept proof test bed. We perform two experiments evaluating the success rate of: i) capturing and storing service messages and ii) searching for a service of interest and receiving reply messages containing it. OSPD feasibility was demonstrated for different vehicle densities and for very short time connections. Results indicate that a vehicle can capture 100% of messages under the coverage of seven POI sending advertisement messages every second, with a contact time of 1.2s. Moreover, a user can find a service with 95% of success rate by querying one neighbour vehicle.