%0 Journal Article
%T An Improved Multipoint Relaying Scheme for Message Propagation in Distributed Peer-to-Peer System
%A Zhiping Liao
%A Song Liu
%A Shengfeng Xi
%J International Journal of Distributed Sensor Networks
%D 2014
%I Hindawi Publishing Corporation
%R 10.1155/2014/792814
%X Message propagation is a primary means to locate resources in current unstructured peer-to-peer (P2P) systems and how to reduce effectively the redundant messages of propagation while keeping its high network coverage is what many researchers go in for in this field. In this paper, we propose the algorithm of LMPR, a scheme of improved MPR for message propagation in distributed unstructured P2P system. Based on analyzing the process and message redundancy of MPR, this paper proposes to add to such scheme a mechanism of specified relay-list to reduce further the number of its retransmitting of message. By attaching to each relay-peer a relay-list with peers it will relay message to, the scheme can assure that in the view of each decision-peer a broadcast message can be dispatched and only be dispatched once to every neighbor peer within 2 hops of it. Simulation results show that the scheme of LMPR has better performance than that of MPR in message redundancy, network overhead, and fluctuation brought to the system. 1. Introduction Peer-to-peer (P2P) systems become immensely popular in recent years and they are used in a variety of contexts, from file sharing applications, distributed storage, to content streaming, and so forth [1, 2]. Among them, fully distributed unstructured P2P systems are the most common ones, with the collaboration of all participants and by virtue of the huge number of peers, objects can be widely replicated, providing the opportunity for high availability and scalability. In such systems, there is no centralized coordinator, each peer only maintains a small amount of neighbor links and the locations of resources are unrelated to the topology of network [3]. Therefore in current fully distributed unstructured P2P systems the locating of resources mostly relies on message propagation, also known as message broadcast, which is to send message from a source peer to all other peers in the network [4, 5]. Many protocols have been proposed for message propagation and flooding-based broadcast is the basic idea of them [2, 6¨C9]. Although this classic technique can diffuse a message reliably and robustly in the network, it consumes a large amount of bandwidth as its cost. As we know, in P2P systems, bandwidth capacity is one of the most precious resources and the traffic should be restricted as much as possible particularly for those of wireless and mobile participants [10, 11]. If this constraint of communication traffic is not considered while designing an algorithm, the system may suffer greatly from performance degradations due to the
%U http://www.hindawi.com/journals/ijdsn/2014/792814/