Performance analysis of unstructured peer-to-peer schemes in integrated wired and wireless network environments

Concurrent with the development of wireless equipment, the development of P2P (peer-to-peer) file sharing schemes for integrated wireless and wired networks is also needed. However, research on P2P file sharing has mainly been done only for wired environments or only for ad hoc networks. In this paper, we evaluate existing P2P schemes and propose unstructured P2P caching schemes for integrated wired and wireless network environments. We analyze existing unstructured P2P schemes and propose two kinds of extended Freenet caching schemes: WDC (wireless dependent caching) and HNS (half node storing). We evaluate the performance of the proposed schemes through simulation. The performance of WDC is similar to wired Freenet, however it can save bandwidth of wireless links significantly by replicating files only at wired nodes. With the HNS scheme, although it utilizes more bandwidth than WDC, nodes keep only half of the files of wired Freenet, and both the number of hops for success and the failure rate decrease. Therefore, the WDC scheme is appropriate for bandwidth-limited wireless links or integrated environments with a low proportion of wireless nodes, while the HNS scheme can provide a smaller number of hops to success and higher success rate as compared to wired Freenet.