Research On Routing Of WSNs For Mobile Sinks

In traditional Wireless Sensor Networks, sinks are static. The sensor nodes closeto a sink will deplete their energy quickly because they have to forward losts of datapackets from many other nodes. Since the sensor nodes are deployed in harshenvironment area and powered by batteries, it will become difficult to recharge thenodes which runs out of energy, and thus shorten the lifetime of the entire network.Since mobile sinks can move to the source shortening the distance of data packetsforwarded, thus saving a lot of energy and prolonging the lifetime of network. Inrecent years, people began to study the routing based on mobile sink and have putforward a variety of algorithms.Geographic routing has been considered as one of the most attractiveapproaches, since it exploits pure location information instead of global topologyinformation, and it is efficient, simple and scalable routing protocol in WSNs. In thispaper, the thesis focuses on location-based routing algorithm.In location convergence algorithm, a lot of network energy has been saved sincemobile sinks needn’t update their present location to the source directly. If thelocation convergence algorithm has a low packets generations rate in source, andwhen mobile sinks move quickly, the problem of larger average delivery delay andlower success delivery ratio will be caused. For the above-mentioned disadvantagesof location convergence algorithm, an agent-based routing protocol (ABR) isproposed. This algorithm has improved the success delivery ratio with the agent ofsink nodes, made a good balance between the network energy consumption andaverage delivery delay and overcome the shortages of location convergencealgorithm efficiently. The simulation results show ABR protocol has greatadvantages in improving the network performance.When a number of sinks move together, the existing protocols which send datato group will cause excessive energy consumption with frequent informationbroadcast in the group. To solve such problem, a routing algorithm for datatransmitted to group is proposed. In the algorithm, the routing overhead of locationupdate is reduced as the group head is responsible for the communication with thesource and network energy is saved and the lifetime of network is prolonged as thedata is only broadcast to sink nodes. The simulation results show this algorithm canreduce the consumption of network energy and prolong the lifetime of networkcompared with RBDD protocol.