Evaluation and comparison of energy efficient node deployment strategies in wireless sensor networks

The lifetime of wireless sensor network is vital issue. Many wireless sensor networks applications have involved deployed sensors, these sensors are unattended for a long time (months or years). Wireless Sensor Networks (WSNs) lifetime can be enhanced if the data flow traffic in the sensor network is modified in a manner that all sensors consumed their energies in a balanced fashion. In our thesis, we studied the problem of energy depletion and sensor network lifetime improvement in many to one communications networks. In such networks, all sensor nodes collect and transmit data to one base station through multi-hop communications. The data flow traffic model is greatly non-uniform. This situation generates heavy traffic load in the nodes near to the base station. In this thesis, a linear program (LP) method has been studied for modeling the theoretical features of the non-uniform node distributions strategies in wireless sensor networks. Gaussian (normal) and exponential node deployment models have been proposed and we have tried to observe the optimal parameters of normal distribution. Also, the effect of base station location on the lifetime of sensor network has been studied in non-uniform and uniform deployment models. Our results indicated that non-uniform node deployment and base station location have significant effects on the energy consumption of sensor nodes. Proposed node deployment models can affect the energy consumption and can balance energy depletion between sensor nodes reaches a particular level.