Reliable Transport Protocol Of Wireless Sensor Network In Wide Area Event-monitoring Application

As the rapid development of wireless communication and sensor technique, wireless sensor network is stepping from research into practice. For its bright future in the area of military, science and commercial, it has become a hot point that attracts the attention of academe and industry. Wireless sensor network are different from traditional networks for its simple nodes, weak wireless communication ability and limited energy, which makes its protocol design highly dependent on applications.Event detection in wide area is one of the main applications of sensor network. Placed in wide area, the sensor network that made up of amount of nodes can exactly monitor the critical condition and report to sink node for purpose of alerting. This application requires the routing protocol to be reliable, fault-tolerant and low latency. Under the conditions of long average transport path and weak channel, what is the most important problem is how to reliably and efficiently transport the packets.Addressing this problem, in this thesis we present a hierarchical reliable event-driven protocol ECRT. In ECRT, the packets are intermediated to sink node between clusters. The Local Path Found mechanism can quickly build a local path through this cluster by using routing-by-demand strategy, and the local paths among different clusters can be connected together to form a complete path to sink. The Cluster-by-Cluster Packet Recovery mechanism can greatly reduce the transport latency and power consumption when using hop-by-hop packet recovery, at the same time guarantee the reliable transport between clusters. ECRT uses Self-adapted Cluster-head Electing Strategy to reset the cluster head inside the cluster without changing the cluster members. This can save the large energy cost when periodically clustering the whole network, especially suitable to the network that is not load balanced。We made theoretic model analyze and implement the simulation on NS-2 platform, proving that ECRT protocol has a better performance in wide area event detection application.