Tsinghua Science and Technology


urban vehicular delay tolerant networks, geocast routing, node forwarding capability, connection time


Nowadays, both vehicular active safety service and user infotainment service have become two core applications for urban Vehicular Delay Tolerant Networks (uVDTNs). Both core applications require a high data transmission capacity over uVDTNs. In addition, the connection between any two vehicles in uVDTNs is intermittent and opportunistic. Intermittent data dissemination over uVDTNs is a stringent and challenging issue. In this paper, we propose Intermittent Geocast Routing (IGR). For the first step, IGR has to estimate the active connection time interval via the moving directions and velocities between any two vehicles. Second, the throughput function for uVDTNs is fitted by building a wavelet neural network traffic model. Third, the throughput function within the effective connection time interval is integrated to obtain the forwarding capability estimation of the node. Fourth, a high-efficiency geocast routing algorithm using the node forwarding capability for uVDTNs is designed. Finally, IGR is simulated on the opportunistic Network Environment simulator. Experimental results show that IGR can greatly improve the packet delivery ratio, transmission delay, delay jitter, and packet loss rate compared with the state of the art.


Tsinghua University Press