在汽車行動網路和網際網路中實作點對點傳輸機制

Abstract

Non-safety related applications of VANET mean for improving driving comfort and efficiency of transportation system are more bandwidth-sensitive. Peer-to-Peer (P2P) approaches can be used to reduce the load of content provider and propagate resources effectively. However, most of P2P systems are originally developed targeting on Interent for wired users. But still, some P2P systems targeting Mobile Ad Hoc networks (MANETs) have been desgined, and consider how to let P2P perform well in wireless environment. However, previous works only consider using P2P in Internet or VANET, it is not sufficient for performing P2P on vehilces. The better method is that vehicles can use peers in Inernet and VANET simultaneously. Peer in vehicles can choose which peer to use according to the environment situation. Since we want to perform P2P over Internet and VANET, peers in our environment will have different properties. We classify peers into Fixed Peer and Mobile Peers. Peer can get resource from both Fixed Peers and Mobile Peers. But not all peers are useful and available for being a content provider. Therefore, we propose to use Connection Lifetime between two peers or between peer and infrastructure as the identification to choose the available peer. By using Connection Lifetime, peer that wants to download file picks up useful peers that can provide enough resources. Also, peer can use Connection Lifetime and bandwidth to estimate how to efficiently download file, and eliminate situation of packet collision. We show through simulation that both our approach can uses Connection Lifetime to search out available peers and download files from those peers effectively.