An Energy-Effective Routing Protocol for Mobile P2P Systems

In the mobile environment, effective use of limited energy of mobile devices is ever required. Especially, in a mobile peer-to-peer (P2P) system, if a mobile device uses all its energy up, it can no longer participate in the system. Furthermore, as the number of peers without energy increases, so does the file search failure rate of the system. In this paper we present an energy-effective routing protocol in a double-layered P2P system that consists of peers in the upper level, called super peers, and other peers in the lower level, called subpeers. The double-layered system allows file searches with much less message traffics compared with a 'single-layered' P2P system by forcing the file searches to be taken among super peers and hence can avoid flooding in the entire network. We introduce two schemes to improve the average lifetime of a network. Functionality and performance were evaluated through various experiments, and the results showed that the protocol combining the proposed schemes improved the average network lifetime by up to 146%.