Research on Methods for Prolonging Wireless Sensor Network’s Lifetime
|School||Shandong Normal University|
|Course||Computer Software and Theory|
|Keywords||wireless sensor network the energy-hole problem lifetime of network payofffunction NS2|
As with the wireless sensor network (WSN)’s continuous progressing andbooming, its application range and prospects are increasingly expending. But still,there are several problems that severely restrict and limit its applying and developing.Because the fact that the network always generates different amount of data atdifferent region, thus leads to the problem of uneven load of transmitting. Nodes thatare in charge of more transmitting work have to consume more energy, especially fornodes in the areas that are near the base sink. Therefore, they are more inclined to beout of use. This is the Energy-Hole (EH) problem. Sensing data could not be sent tothe Base Sink and there would be a sensing blind spot in the WSN when EH appears.The Energy-Hole problem shortens the lifetime of WSN critically. When the EHfirst appears, it would lead the WSN to an unstable state which means that there maybe many transmission delay problems and security problems and so on. When the EHproblem lead to the invalid of the WSN, there still much energy left in nodes thatbelong to other regions. This shortens the lifetime and reducing the quality of service,meanwhile this is quite a waste of WSN’s application and leaves a lot of E-waste.In this paper, the cause of the Energy-hole (EH) problem and its adverse effectsare stated in the first place. During the investigation, we did a lot follow-up studies,and then summarized methods and solutions to the EH problem. After this wededucted the energy consumption of a node using the Corona model. The best solutionfor energy consumption is to find out the optimal transmission range list for everynode, but that is an NP-hard problem. With the conclusions above, an algorithm isfurther proposed to find out a routing path from a node to the sink which consumesminimal total energy. The computation starts form the nodes located at inner corona toan outer one. By doing so, the recursion and the computational complexity could bereduced.Furthermore, another algorithm is proposed to control the low-energy node’sexpenditure. Nodes that have spent too much energy will be eliminated from the set ofworking nodes. Thus could prevent them from running out of energy too fast. As forthe situation that there is no available nodes could serve as a net hop in a region, the algorithm makes the low energy nodes in that region calculate the payoff ofparticipating in transmitting data. Then set the node which has the biggest payoffvalue as the next hop. Using the tow algorithms to avoid the emerging of theEnergy-hole and prolong the lifetime of WSN.Finally, the simulation experiment is carried out using the Network Simulationversion-2(NS2) on Ubuntu system. Then we collect statistics and analyze theoutcomes. Comparison with the original protocol shows that these two algorithmcould prolong WSN’s lifetime effectively and significantly.