Peer-to-Peer Data Dissemination for Deadline-Sensitive Streaming in VANETs

In this paper, a mechanism of Peer-to-Peer (P2P) data dissemination for distributing deadline-sensitive streaming files in Vehicular Ad-Hoc Networks (VANETs) is proposed. In a multi-media application sensitive to deadline, the data requested by the peer needs to be received before its playback deadline. For the purpose, we adopt different strategies from the previous works, as follows. First, a distinct lookup function is designed by just collecting the part information of data distribution to reduce the network overhead. It is executed simultaneously with the task of requesting data to take advantage of the timeliness of collected information. Second, in order to utilize the limited bandwidth of VANETs efficiently, the function in requesting data schedules only data sufficient to meet the playback rate requirement of the service. Third, a method is designed to provide deadline-sensitive segment dissemination and alleviate the problem of the highly mobile hosts in VANETs. It interactively uses the estimated and actual historical values of the transmission time between two neighboring hosts and the period of two neighboring hosts remaining connected. Fourth, to further alleviate the mobility problem, a route recovery function is designed to recover a disconnected route timely, and a system parameter can be set according to host speed. Fifth, the setting of the system parameter can be a trade-off between the playing quality of the service and the capacity of the network. Compared with a very recently related work, the effectiveness of this mechanism has been verified by a lot of simulations. When the hosts in the network are static, the admission peers of the mechanism increases by 18% compared with the recent work. On the other hand, when the hosts are dynamic, the mechanism improves 10-25% and 0-14% in admission peers and timely received data over the recent work, respectively.