Research On Transmission Control And Routing Protocols In Wireless Sensor Networks

Sensor network, which is made by the convergence of sensor, system-on-chip and networks technologies, is a novel technology about acquiring and processing information. Through the real-time collaboration of the integrated micro-sensors, it can be used for sensing and processing information, and then can provide a large amount of reliable information. It has broad application prospects not only in military applications, environmental monitoring but also in disaster rescue, space exploration and so on.The event-driven nature of wireless sensor networks (WSNs) leads to unpredictable network load. As a result, congestion may occur at sensors that receive more data than they can forward, which causes energy waste, throughput reduction, and packet loss. In this paper, we propose a rate-based awareness-fair congestion control (AFCC) protocol, which controls congestion and achieves approximately fair bandwidth allocation for different ?ows. In AFCC, we categorize intermediate relaying sensor nodes into near-source nodes and near-sink nodes. Near-source nodes maintain a per-?ow state and allocate an approximately fair rate to each passing ?ow. On the other hand, near-sink nodes do not need to maintain a per-?ow state and use fairness of the stateless queue-management mechanism. Our simulation results and analysis show that AFCC provides better performance than previous approaches in terms of throughput, packet loss, energy ef?ciency, and fairness.Mobile sensor networks utilize the communication opportunities arising from node movement to forward messages in a hop-by-hop way, and implement communications between nodes based on the"store-carry-forward"routing pattern. In this study, we consider five types of non-collaborative behavior, namely free rider, black hole, supernova, hypernova and wormhole behavior, in mobile sensor networks. We also evaluate the impacts of the five types of behavior on the data transmission performance of three widely used routing schemes. Simulation results of experimental network show that the data forwarding performance degrades significantly as the number of non-collaborative peers, except wormholes, increases.