Optimum Node Deployment Policy (ONDP) for WSN: trade-off between maximization of area coverage and lifetime

There are different methods of optimizing energy usage of sensor nodes for increasing the life time of wireless sensor network. The first node death time is considered to be the effective life time of any network. Therefore, our objective is to adopt such routing algorithms and node deployment policy so that no individual node dies sooner while others are alive. There are different reasons for the early death of first node, which at extreme cases may lead to partition of the network. One of the important reasons for which node energy might run out early is that number of transmitted messages per geographic area unit is different. A node is more likely to run out of its energy earlier than the others in an area where message density is high. Therefore, if we can predict the areas in the network where message density is likely to be higher than the rest of the area in the network, then we can increase node density while aiming at uniform energy dissipation. The nodes which reside nearer to the sink node face huge traffic load that lead to non-uniform energy dissipation. Hence, node density nearer to the sink node has to be increased. In this paper, to increase the lifespan of wireless sensor network, we explore this concept to obtain the best possible solution.