Energy-efficient mobile data collection in Wireless Sensor Networks with delay reduction using wireless communication

In a Wireless Sensor Network (WSN), battery power is a limited resource on the sensor nodes. Hence, the amount of power consumption by the nodes determines the node and network lifetime. This in turn has an impact on the connectivity and coverage of the network. One way to reduce power consumed is to use a special Mobile Data Collector (MDC) for data gathering, instead of multi-hop data transmission to the sink. The MDC collects the data from the nodes and transfers it to the sink. Various kinds of MDC approaches have been explored for different assumptions and constraints. But in all the models proposed, the data latency is usually high, due to the slow speed of the mobile nodes. In this paper, we propose a new model of mobile data collection that reduces the data latency significantly. Using a combination of a new touring strategy based on clustering and a data collection mechanism based on wireless communication, we show that the delay can be reduced significantly without compromising on the advantages of MDC based approach. Using extensive simulation studies, we analyze the performance of the proposed approach and show that the packet delay reduces by more than half when compared to other existing approaches.

I. Introduction

A Wireless Sensor Network (WSN) is a network of small devices, called sensor nodes, that are embedded in the real world for observations related to an application and are connected by a wireless network [1]. Protocol designers for WSNs place a high emphasis on energy conservation, since the nodes run on limited battery power. Data generated by the nodes is typically transmitted to the sink over a multihop wireless network. In such a network, a node might spend most of its power relaying other nodes' packets, depleting its battery. Over time, as nodes die out, the network tends to get disconnected, leading to loss of coverage and connectivity.