P2p Overlay Network And Sensor Network Routing Protocols

Modern Peer-to-Peer(P2P)networks present several unique aspects that distinguish them from traditional distributedsystems.Networks comprising hundred of thousand or even millions of peers are not uncommon.As a consequence of such scale,they are characterized by extreme dynamism,with a continuous flow of nodes joining or leaving the network.The concept of superpeer(SP)has been introduced to improve the performance of popular filesharing applications.A superpeer is a node in a P2P network that operates as a server for a set of clients,and as an equal with regard to other superpeers.By exploiting heterogeneity, the superpeer paradigm allows P2P networksto run more efficiently,without compromising their decentralized nature.However,the current constructing protocols are inefficient.A wireless sensor network(WSN)is a collection of wireless sensor nodes forming a temporary network without the aid of any established infrastructure or centralized administration. Efficiently locate data is a fundamental problem for future applications of wireless sensor network.It is known that Distributed Hash Table(DHT)based Internet P2P protocols provide near-optimum data lookup times for queries made on networks of distributed nodes.Using a DHT based network protocol to serve queries in WSNs becomes an important problem to study.However,a generic mapping of DHT based Internet protocols to WSNs is considered difficult as these protocols typically interconnect nodes independently of their proximity in the physical network topology which is not suitable for energyconstrained sensor networks as neighbors in the DHT logical identifier space may actually be far apart and each logical hop within a DHT may cost energy of many packet transmissions.Furthermore,in the energy-constrained WSNs environments,particularly in large scale WSNs,maintaining routing information among all pairs of nodes becomes expensive.One important issue when designing WSN is the routing protocol that makes the best use of the severely limited resource presented by WSN,especially the energy limitation. Clustering provides an effective way for prolong ing the lifetime of a wireless sensor network. Current clustering algorithms usually utilize two techniques,selecting cluster heads with more residual energy and rotating cluster heads periodically,to distribute the energy consumption among nodes in each cluster and extend the network lifetime.In additon, there is the strategy to make use of the energy of base station(BS)as soon as possible. That is,BS does everything,from broadcasting control packets,routing paths selection and maintenance.Sensor nodes are only responsible for basic functions,such as sensing data, forwarding packets on behalf of other nodes and sending sensing data to BS.This thesis mainly is divided into five chapters.In the first chapter we illuminate back- ground of our study and put forward of the problems,the work we do and the structure of the theis.The second chapter we propose an efficient and robust adaptive superpeer P2P overlay network ERASP.A novel two-tier Chord based network protocol for serving efficient queries in wireless sensor networks(C2WSN)is proposed in the third chapter.In the fourth chapter we propose an energy-efficient multi-hop routing protocol for wireless sensor networks(EEMR). The fifth chapter mainly presents the future work.