Improved Harmony Search Algorithm for Multihop Routing in Wireless Sensor Networks

Energy efficiency is critical for prolonging the network lifetime of Wireless Sensor Network (WSN), and is the most important objective for any routing algorithm for WSN. In this article authors have proposed a Multihop harmony search algorithm for WSN with two objectives, first being increasing the throughput of the network and second being optimizing the energy consumption of the sensor nodes and thereby prolonging the lifetime of network. Finding the goodness of the communication channel/path is quite important. Sometimes, though the channel capacity is more, fewer amounts of data may be transmitted in the channel resulting in under utilization of the resources; and other times, though the channel capacity is less, more data may be dumped into the channel resulting in channel congestion and less output. Thus, if the goodness of the communication channel is known in advance, then it is easy for the algorithms to decide the upper bound of the channel and can have a congestion free and error free information transmission. Thus, the proposed algorithm employ Shannon channel capacity 'C' (baud rate) for finding the best next hop and the same is used for initialization of Harmony Memory. An effective local search strategy is also proposed to strengthen the local harmony search ability so that the convergence speed and the accuracy of routing algorithm is improved. Finally, an objective function model is developed by taking path length, energy consumption, and residual energy in to consideration. The proposed algorithm is compared with existing Multihop LEACH, BRM (Baud rate based Multihop routing protocol) and EEHSBR (Energy Efficient Harmony Search Based Routing) algorithm for the quantitative and qualitative analysis. The simulation results reveal that the proposed algorithm performs better than the considered algorithms in terms of network lifetime, throughput and energy consumption.