A hybrid communication architecture for intelligent shared vehicle systems

There has been a large degree of activity in the communications arena of intelligent transportation systems. Various communication linkages are being developed for a variety of ITS applications for different purposes. Shared vehicle systems, as a relatively new transportation paradigm, are very well suited for the application of ITS technology, including advanced communication techniques. In general, a shared vehicle system typically consists of a fleet of vehicles that are used several times each day by different users. They offer the convenience of the private automobile and more flexibility than public transportation alone. There are many potential advantages to shared vehicle systems, including improved transportation efficiency, lower transportation cost, an energy/emission benefit, and increased use of existing transit systems. In this paper, we focus on the application of wireless communications to shared vehicle systems. In particular, we describe the design and development of a unique hybrid data communication architecture for a multiple-station shared vehicle system. This hybrid architecture is composed of vehicle-to-system communications using both DSRC (Dedicated Short Range Communications) and CDPD (Cellular Digital Packet Data) methods. Based on the communication needs within a multiple-station shared vehicle system, the hybrid communication system has been designed and optimized in terms of data packet loss, message latency, and system cost. Several experiments have been carried out, examining these measures of performance.