Data Handover Scheme with Weighted Mean N for Lifetime Enhancement in Wireless Sensor Networks

Wireless Sensor Networks being limited energy source, it must function in energy efficient manner to increase the net lifetime of the network i.e. gathering more information for a longer period from the area sensed.Because of limited battery charge, bandwidth and nodes in the transmission range direct communication between sensing nodes to the sink is not a optimal solution for both bandwidth and energy point of view. While the LEACH protocol is used as randomizing cluster heads for equal energy dissemination, the PEGASIS protocol uses a chain of cluster heads participating in different rounds for transmitting data to the base station. As the base station can locate at any distances from the individual nodes, in spite of randomization and chain of cluster heads formation, each node actually dissipates a different amount of energy during its turn of transmission to the base station. DHS takes out this energy difference by data handover in specific cycles through suitable node pairing. But the main limitation of this scheme is its inapplicability to networks with large number of nodes due to the huge amount of computations, in LCMs as proposed in, to be carried out for determining the cycle in which a particular pair of nodes should execute a handover. This might time as well as energy consuming. Also, the expanse of self-energy in handover depending on the distance between participating nodes will become considerable if too many handovers take place. In this paper, we propose DHS-with-mean, according to which, all the nodes handover in the same mean cycle, thereby eliminating LCMs, and reducing the complexity of the computations remarkably. Also, we have proposed half DHS with mean, in which not all but only 50% of the nodes execute handovers. Finally, we have proposed 10% DHS-we have experimented with the percentage of nodes participating in handover and have found 10% to be the optimal percentage of nodes to be participating in handover for achieving the maximum ne- - twork lifetime. Extensive simulations show half DHS gives on the average 3.15%, 5.52%, 3.6% and 6.03% improvement in network lifetime over and above the 10%, 12%, 17%, and 20% improvement achieved by DWeMen alone on PEGASIS, the binary model, LEACH and the direct scheme respectively. Moreover, 10% DHS achieves a further 3.15% and 4.88% improvement over half DHS, in case of PEGASIS and binary model respectively. It thus presents a near optimal solution for equal energy dissipation enhancing network lifetime, for any number of nodes.