Telsiz görevdeş ağlarda kullanıcı işbirliğinin performans analizi

Peer-to-peer (P2P) architectures for file sharing among ad hoc, possibly dynamic, collections of hosts are generating an increasing fraction of the traffic on today's Internet and are reshaping the way new network applications are designed. The idea is to have hosts participate in an overlay network, enabling signaling, routing, and searching among participating hosts. Once a host locates the document(s) of interest, direct connections are established to mediate their transfer. The key principle is to allow, and in fact encourage, participating hosts to play dual roles as servers and clients - thus hosts are considered peers.Recently, wireless peer-to-peer networking has gained attention in the research community, where the peers are distributed over the geography and are capable of cooperation in a wireless fashion. The wireless scenario introduces specific design challenges; the wireless channel is time-varying and hostile, and the system resources, in terms of available transmission power and bandwidth, are scarce. In this study, building on the recent body of work on cooperative networks, we aim to develop an information theoretic framework to assess the performances of various peer-to-peer protocols that may be considered in the wireless regime. Various design criteria will be studied: maximization of the system capacity, minimization of the average download time, fairness among peers in energy utilization, optimal rate allocation to the layers when scalable video transmission is considered.