On Area Coverage Reliability of Mobile Wireless Sensor Networks With Multistate Nodes

Wireless sensor networks (WSNs) are a special type of infrastructure-less network made up of a large number of tiny sensor nodes with limited energy, processing, and communication capabilities. WSNs have applications in health care, home security, environment monitoring, etc., with research challenges in energy efficiency, network lifetime, and network reliability. One of the major research challenges lies in providing application-specific coverage of the region of interest and reliable transmission of the gathered data to the mobile sink in the presence of multi-state sensor nodes. To quantify such a capability, this paper proposes a quantitative measure, called Area Coverage Reliability (ACR) for WSNs. ACR brings together WSN reliability, area coverage, energy efficiency, mobility of data collector or sink, random duty cycle of nodes, and multi-state nature of sensor nodes under a common umbrella. This paper proposes a Monte Carlo simulation approach that utilizes an energy matrix to evaluate the effect of energy-depleted nodes and energy-oriented data transfer capability on ACR. The energy matrix reflects the residual energy of sensors, the energy required to transmit data to the neighboring nodes, connectivity, and the multi-state nature of the sensors. The proposed approach is illustrated through a series of random examples. The ACR information allows the network designers to achieve a better understanding of the impact of random duty cycle, node energy, node/link reliability, and randomly deployed sensors on reliability.