Analytical modeling of spatial variation of energy dissipation in cluster-based wireless sensor networks

Wireless sensor network protocols commonly use clustering to reduce the rate of energy dissipation in the system. With this technique, some nodes are selected as cluster heads and the remaining as member nodes so that cluster heads mainly use energy transmitting to the base station and member nodes transmitting to their cluster head. For the latter, the amount of energy used depends on the distance to the nearest cluster head, which in turn depends on the node´s position in the field. The cluster head of nodes near the edge is farther away on average than cluster heads of nodes near the center, resulting in uneven energy dissipation. This unevenness has an important impact on sensor coverage as node lifetime is shorter near to the edge of the field than in the center. In this paper we present an analytical model for both the distance to the nearest cluster head as a function of a node´s position within the field and for energy use. Such an analytical model makes it easy for researchers to determine the impact of spatial factors such as edge effects and base station position without incurring the cost of simulation.