Researches On Vanet Middleware For Service Sharing Based On OSGi

Vehicular Ad-hoc Network(VANET)realizes the communication on vehicle-to-vehicle,vehicle-to-road,makes data communication on traffic system faster and more convenient,enabling intelligent traffic management and information services.The VANET middleware is the link of information exchange between automotive embeded devices and VANET applications,providing unified and common interfaces to manage and invoke automotive basic services.How to decouple applications from devices,improve the flexibility and scalability of the system,and access to heterogeneous devices and resources transparently,have become the main problems need to be solved in the VANET middleware.This paper proposes a service oriented middleware for VANET,called VANET middleware for service sharing based on OSGi.This middleware platform using the OSGi service oriented advantage,various kinds of functions provided by sensing devices in vehicles are virtually abstracted as services in network,which decouples VANET applications from devices and provides a unified platform for data exchange among vehicles.The main contributions of the paper are as follows:Through the study of the methods such as SOA,OSGi and service discovery architecture,VssOSGi is presented to solve the problems of heterogeneous devices which can not achieve service sharing.To find and invoke services provided by vehicle in VANET,a service sharing mechanism based on distributed service directory is proposed.Through establishing service directory dynamically and binding services dynamically,VssOSGi can get access to the resource and services in VANET easily and realize sharing services among vehicles.Through demand analysis for VANET applications,there are a large number of based location service scenarios for VANET.This paper studies and designs a location-based service discovery protocol LbSDP.LbSDP is designed for location-based service.Through building service and location relational model,we associated service request with geographic information.In order to reduce service discovery time and network overhead,LbSDP aggregates service reply messages in a best-effort way in predetermined time.Simulation results show that LbSDP can improve the efficiency of service discovery and help users to discovery required services in the region of interest quickly.Finally,we simulates service sharing scene among vehicles using VssOSGi and evaluates in terms of the response time,the number of request messages and the success rate of service discovery.