Wireless Sensor and Actuator Networks-Based Reliable Data Acquisition Mechanism

Introduction

A Wireless Sensor Network (WSN) is deployed with the purpose of acquiring information and then passing on the acquired information to a remote sink where the information can be used to estimate or re-construct the environment or event. This requires the WSN to have the ability to sense the parameter or event under consideration, in the region of deployment, and then ensure reliable delivery of the information to a centralized sink where the information sensed by it can be used to re-construct the events (Abroshan, S., & Moghaddam, M. H. Y. 2014). However, in context of the Wireless Sensor & Actuator Networks the Network Latency time assumes much greater importance since the action taken by the Actuator nodes has to be time coherent with the event sensed by the deployed nodes failing which the control loop will become un-stable and erratic.

This chapter presents a novel Reliable Data Acquisition methodology using Wireless Sensor & Actuator Networks which meets the criterion of reliability as mentioned above. The proposed methodology, ensures, regarding a sensed event is reported to the centralized sink / Actuators for acceptable estimation or re-construction of the event detected, within the time constraint fixed by the control action to be taken by the Actuator nodes.

The objective in this approach is for the Sensor Network to continue its operation with as high reliability as is feasible under the given fault condition in the network (Adelstein, 2005). The fault conditions could vary from temporary loss of communication between a set of nodes, to permanent loss of a node because of damage or end of battery life of the node. The focus of design of algorithm tends to be on ensuring detection of event and then delivery of sensed despite the fault condition. Some algorithms also focus on detection of fault condition itself and then managing it.

Majority of these solutions propose algorithms with the ability to dynamically find alternate network paths in case a given network becomes un-usable because of a fault condition. Many algorithms present methodology where the data sensed is transferred on multiple paths simultaneously to begin with thus ensuring delivery of information at sink despite some path becoming useless because of node failure (Ali, S., Fakoorian, A. & Taheri, H. 2017).