Modelling and Enhancing the Data Capacity of Wireless Sensor Networks

Energy conservation is one of the most important design considerations for battery powered wireless sensors networks (WSNET). Energy constraint in WSNETs limits the total amount of sensed data (data capacity) received by the sink. The data capacity of WSNETs is significantly affected by deployment of sensors and the sink. A major issue, which has not been adequately addressed so far, is the question of how node deployment governs the data capacity and how to improve the total data capacity of WSNETs by using non-uniform sensor deployment strategies. In this paper, we discuss this problem by analyzing the commonly used static model of sensors networks. In the static model, we find that after the lifetime of a sensor network is over, there is a great amount of energy left unused, which can be up to 90% of the total initial energy. This energy waste implies that the potential data capacity can be much larger than the capacity achieved in the static model. To increase the total data capacity, we propose two strategies: a non-uniform energy distribution model and a new routing protocol with a mobile sink. For large and dense WSNETs, both of these strategies can increase the total data capacity by an order of magnitude.