In this paper, the WSN model is derived from [12] with the following assumptions: the WSN consisting of a number of sensor nodes uniformly distributed in the sensing field. We assume a network equipped with one or more source nodes and one sink whereby the data flow is generated at the source nodes intended for the sink node. The remaining nodes serve only as intermediate nodes with no additional sensed data. The sensor nodes are immobile and have similar capabilities with respect to the signal processing and the communication features. The sensor nodes are equipped with batteries as the power source. The initial available energy of each node is set to a constant value. The sensor nodes are capable of controlling the power with the ability to change the individual transmission power in order to vary the communications range.