Study On Routings Of Large-scale WSN For Event Monitoring Applications

In wireless sensor networks, the energy resource and processing capacity of sensornodes are so limited, which impose restrictions on a further development and expansionof the applications of wireless sensor networks. An effective and applicable routingprotocol can make up for the limitation of sensor nodes and then make for a good workof the wireless sensor network.The wireless sensor network has various requirements for the routing protocolaccording to different application scenes. As one of the important applications ofwireless sensor networks, event monitoring has more requirements on energy efficiencyof routing protocol due to the large-scale networks, the wide areas and the randomnessof events. Based on this point, this paper makes lots of related research and analysis oftypical routing protocols, and obtains some effective strategies for event monitoringapplications of large-scale wireless sensor networks, and then designs reasonable andapplicable routing protocols according to the characteristics of this application. Themain works are as follows:①Making a systematic study on the system and applications of wireless sensornetwork, the common characteristics and requirements of wireless sensor networkrouting protocols design. Researching the details of several typical routings such asLEACH, AEEC and ARPEES, and analyzing their advantages and shortages withrespect to event monitoring application of large-scale wireless sensor network, and thenobtaining some effective routing strategies.②Proposing a routing protocol for emergency monitoring of wireless sensornetwork which is based on event-driven clustering and delay grades tree. In order tosave and balance energy consumption of the whole network, the protocol takes severalfacts of the node such as the residual energy, the hops to the sink node, the connectivitywith neighbor nodes and the number of father-nodes into account when electing clusterheads. In addition, the delay grades tree and multi-path selection guarantee the real-timeand reliable data transmission. Comparing with the existing routings, the proposedprotocol can reduce the delay of data transmission, improve the energy efficiency andincrease the lifetime of wireless sensor network.③As the effective working time of wireless sensor network decreased due toearly dead nodes with the existing clustering routings, an improved protocol is proposed to increase the effective working time of network by maintaining a high proportion ofliving nodes, which takes connectivity into account in cluster head election procedure.Furthermore, according to the residual energy of current nodes, a back-propagationrouting strategy is proposed to properly select relay nodes as well as prevent the currentnodes with less energy going to dead too early. Numerical results show that theproposed protocol prolongs both the lifetime and the effective working time of thenetwork. Even in enlarged areas, the proposed protocol displays an obvious advantagewith respect to the existing protocols as well.