Mobile Wireless Sensor Network Routing Protocol Research And Design Opportunities

In mobile sensor networks, node mobility enables network topology tochange dynamically, the network is not stable due to the fact that end-to-endtransmission path is changeable, while traditional wireless sensor networkrouting protocol is based on a stable network transmission path of thisassumption, therefore it is not suitable for mobile sensor networks. In addition,the limitation of node energy also brings difficulty to the design of routingprotocols and optimization. As compared with traditional wireless routing,Opportunistic Routing (OR)[1][2]takes full advantage of the broadcasting natureof wireless channel, as well as the time-varying characteristic of wirelesschannel. Thus, OR has effectively improves the throughput and transmissionreliability of wireless multiple hops network, has become one of hot topics in thestudy of wireless sensor network routing. However, Opportunistic Routing isstill facing many urgent problems, such as forwarding-candidate selection,spatial reuse, and so on. To solve these problems, this thesis mainly focuses onthe designing of Opportunistic Routing for Mobile Wireless Sensor Networks．According to the mobile wireless sensor network, opportunistic routingOR-MWSN for mobile sensor networks was introduced and based on RSSImechanism. The OR-MWSN without the need for additional equipment support,move through the path loss and node vectors to evaluate the link quality andestablish the nodes forward the candidate set depend on the broadcastcharacteristic of the wireless link and node mobility. OR-MWSN uses themechanism of the four-way RTS-CTS handshake to coordinate, and based onpath loss rate to allocate candidate forwarding node priority, Ensures that thenodes, which have a small path loss rate and a good quality links, become thebest forwarding nodes. The OR-MWSN does not need a large number ofinteractions between nodes message, at the same time, it can largely reactionchannel quality. We have implemented OR-MWSN in NS2. In term of packetdelivery ratio and network throughput, compared with AODV routing, TheOR-MWSN routing is suitable for mobile sensor networks. To solve the problem of spatial reuse and redundant copy packets, we haveproposed an Opportunistic Routing based on Partial Network Coding, namedOR-MWSNPNC. In OR-MWSNPNC, forwarding candidate nodes randomlychoose received packets to encode new packet with random length and thedestination node can decode original packets randomly. OR-MWSNPNC usesthe non coordination mechanism based on coding technology, while using aportion of the network coding, reducing network latency, but also solves theproblem of repetitive redundancy. We have implemented OR-MWSNPNC inNS2. Simulation results show that: The packet average delay ofOR-MWSNPNC is commonly smaller than that of MORE. At the same time,compared with OR-MWSN, the OR-MWSNPNC improves the network averagethroughput.