Effect of Number of Active Nodes and Inter-node Distance on the Performance of Wireless Sensor Networks

Wireless Sensor Networks (WSNs) are used to monitor different ambient conditions. These networks can be used for constant environment and habitat monitoring applications such as sensing of humidity, temperature, soil moisture and fire. All these applications have certain desired network performance and lifetime requirements. In this paper, we present our findings about variation in network performance and energy efficiency with varying number of active nodes and inter-node distance in WSNs. Change of network behavior with changing network conditions is studied through simulations carried out in ns2.34.

1. Introduction

Wireless Sensor Networks (WSNs) are being extensively used for environment and habitat monitoring applications. Some of these applications are sensing of humidity, temperature and soil moisture. Other critical applications where WSNs can be used are patient monitoring and fire sensing. All these applications have different operation and performance requirements. In applications such as sensing of humidity, temperature and soil moisture, more emphasis is given to node energy and network lifetime. Such applications require low data rate but longer node and network lifetime. While, in applications such as fire sensors and patient monitoring, the duty cycle of the network is expected to be high, along with faster communication. This leads to higher consumption of node energy, thus reducing the network lifetime.