Research On Energy-efficient Routing Protocol In Wireless Sensor Networks

Wireless sensor networks(WSNs) have been much concern at home and abroad in recentyears. The Sensor nodes can monitor and collect the environment information. By composing themultihop and self-organization routing, the nodes can send the sample data in monitor area backto the Sink node. Wireless sensor nodes are usually powered by limited batterie, as a result,constrained energy is a prominent feature for WSNs. Optimizing the energy consumption ofsensor nodes to prolong the network lifetime is one key step to make wireless sensor networksinto practical applications. Routing Protocol takes charge of per hop transmission of data fromsensors nodes to sink，which is one of key technologies of WSNs and has significant impact onthe network performance. Since the radio transceiver typically consumes more energy than anyother hardware component onboard a sensor node, designing energy-efficient routing algorithmsis of great importance to prolong network lifetime.This thesis focuses on WSNs energy-efficient routing protocol. Based on efficiency andbalance of the node energy consumption, it uses some methods such as energy and distanceprediction function, multipath mechanism, ant colony optimization and event clustering to designenergy-efficient routing protocols.The main work and achievements of the thesis are as follows:1. An EDP-AOMDV protocol based on AOMDV is proposed. The path setup phase createsa number of good paths between source and destination, indicated in the routing tables of thenodes. When a node has multiple next hops for the destination of the data, it will randomly selectone of them with probability according to the energy values of the entries. The probabilisticrouting strategy leads to data load spreading according to the estimated minimum residualbattery energy of the paths. Through energy and distance prediction function, Nodes in networkcan send warning message before the route link failure, thus source node can switch route orsearch new route in time. In particular, EDP-AOMDV reduces the packet loss and achieves aimprovement in the end-to-end delay. With the probabilistic routing strategy, the protocol alsoprolongs the lifetime of the wireless network. 2. In this paper, we use the ideas of naturally occurring ants’ foraging behavior and based onthose ideas, we design an multipath energy balance routing protocol ABMR, which not onlyincorporates the effect of power consumption and congestion in routing a packet, but alsoexploits the multipath transmission properties of ant swarms, and, hence, a number of good pathsbetween source and destination are created with different pheromone values. On the other hand,an improved pheromone update formula is adopted, the pheromone deposits of each link becomemore balance.When a node has multiple next hops for the destination of the data, it willrandomly select one of them with probability according to the pheromone values of the routeentries. Simulation results show that ABMR has better delivery ratio, achieves a improvementin the end-to-end delay and expands the lifetime of the network.3. This thesis presents An Energy-Efficient Ant-Based Multipath Routing Algorithm forWireless Sensor Networks. Since one of the main concerns in WSNs is to maximise the lifetimeof the network, which means saving as much energy as possible. To implement these ideas, thememory of each forward ant is reduced to just two records. The packet structures for forwardants and backward ants are designed independently. To save energy, the source node doesn’t sendout proactive forward ants according to the data sending rate. While a data session runs, thetraversal of each data packet decreases the pheromone values of each link. On the other hand,Search ants travel from the destination node and add pheromone on the paths which they havepassed by so as to supply some prior knowledge to the forward ants. Finally, our schemes minifycommunication loads and maximize energy savings, contributing to expand the lifetime of thenetwork.4. In order to design a routing protocol that is applied in the event-driven and queryenvironment, an improved CAEMP protocol based on the clustering and improved ant colonyoptimization is proposed. CAEMP can divided into three phase, which is cluster formation,constructing multipath and data transmission. Firstly, a cluster head is competed among nodeslocated in the event area according to some parameters, such as residual battery energy, thenumber of node’s neighbor and the signal strength. The backup cluster head algorithm is adopted.If destination node wants to check some information, search ants travel from the destination nodeand add pheromone on the paths which they have passed by so as to supply some priorknowledge to the forward ants. Secondly, a number of good paths between the cluster head anddestination are created with improved ACO algorithm. Finally, the aggregate data from clusterhead will randomly select one of route with probability according to the pheromone values of the route entries. The simulation results show that CAEMP can prolongs the network lifetime, andreduces the average energy consumption effectively.5. In the reasearch of vehicular ad-hoc network protocol, the protocol GPSR based ongeographic information is a hot research. An improved protocol based on GPRS is proposed, itcan reduce the impact of routing void, using the ant colony routing algorithm to search for a newrouting. On the other hand, in terms of theintersections in urban area, the proposed protocol addsa predictive mode topredict the forward angles and positions of vehicles at the intersections toimprove the efficiency of routing protocol. The simulation results show that the proposedprotocol improves the performance in urban area.A number of illustrative simulations are given to show the effectiveness of proposedprotocols. Finally, the conclusion and future work are presented.