Network Design and Routing in Peer-to-Peer and Mobile Ad Hoc Networks

Routing;Overlay topology;Mobile ad hoc networks;Peer-to-peer

Merugu, Shashidhar ; Computing

University:Georgia Institute of Technology

Department:Computing

关键词: Routing;    Overlay topology;    Mobile ad hoc networks;    Peer-to-peer;   

Others  :  https://smartech.gatech.edu/bitstream/1853/7219/1/merugu_shashidhar_200508_phd.pdf

美国|英语

来源: SMARTech Repository

【 摘 要 】

Peer-to-peer networks and mobile ad hoc networks are emergingdistributed networks that share several similarities. Fundamentalamong these similarities is the decentralized role of eachparticipating node to route messages on behalf of other nodes, andthereby, collectively realizing communication between any pair ofnodes. Messages are routed on a topology graph that is determined bythe peer relationship between nodes. Although routing is fairlystraightforward when the topology graph is static, dynamic variationsin the peer relationship that often occur in peer-to-peer and mobilead hoc networks present challenges to routing.In this thesis, we examine the interplay between routing messages andnetwork topology design in two classes of these networks --unstructured peer-to-peer networks and sparsely-connected mobile adhoc networks.In unstructured peer-to-peer networks, we add structure to overlaytopologies to support file sharing.Specifically, we investigate theadvantages of designing overlay topologies with small-world propertiesto improve (a) search protocol performance and (b) networkutilization. We show, using simulation, that "small-world-like"overlay topologies where every node has many close neighbors and fewrandom neighbors exhibit high chances of locating files close to thesource of file search query. This improvement in search protocolperformance is achieved while decreasing the traffic load on the linksin the underlying network.In the context of sparsely-connected mobile ad hoc networks wherenodes provide connectivity via mobility, we present a protocol forrouting in space and time where the message forwarding decisioninvolves not only where to forward (space), but also when to forward(time). We introduce space-time routing tables and develop methods tocompute these routing tables for those instances of ad hoc networkswhere node mobility is predictable over either a finite horizon orindefinitely due to periodicity in node motion. Furthermore, when thenode mobility is unpredictable, we investigate several forwardingheuristics to address the scarcity in transmission opportunities inthese sparsely-connected ad hoc networks. In particular, we presentthe advantages of fragmenting messages and augmenting them witherasure codes to improve the end-to-end message delivery performance.