Sensors Lifetime Enhancement Techniques in Wireless Sensor Networks - A Survey

TL;DR

This survey reviews energy conservation techniques in wireless sensor networks, focusing on MAC and routing protocols to extend sensor and network lifetime amid environmental deployment challenges.

Contribution

It categorizes and analyzes state-of-the-art MAC and routing protocols, emphasizing energy-efficient strategies for prolonging WSN lifespan without relying on location-based routing.

Findings

Routing protocols are mainly data-centric and hierarchical.

MAC protocols can be schedule-based or contention-based.

Energy conservation is achieved by reducing collisions and retransmissions.

Abstract

Wireless Sensor Networks are basically used for gathering information needed by smart environments but they are particularly useful in unattended situations where terrain, climate and other environmental constraints may hinder in the deployment of wired/conventional networks. Unlike traditional networks, these sensor networks do not have a continuous power supply at their disposal. Rather the individual sensors are battery operated and the lifetime of the individual sensors and thus the overall network depend heavily on duty cycle of these sensors. Analysis on WSNs shows that communication module is the main part which consumes most of the sensor energy and that is why energy conservation is the major optimization goal. Since routing protocols and MAC protocols directly access the communication module therefore the design of protocols in these two domains should take into account the energy conservation goal. In this paper, we discuss different state-of-the-art protocols both in MAC and routing domains that have been proposed for WSNs to achieve the overall goal of prolonging the network lifetime. The routing protocols in WSNs are generally categorized into three groups - data centric, hierarchical and location-based but we focus on only the first two categories because location-based routing protocols generally require a prior knowledge about sensors location which most of the times is not available due to random deployment of the sensors. We then discuss how schedule-based and contention-based MAC protocols can contribute to achieve optimal utilization of the limited energy resource by avoiding or reducing the chances of collisions and thus the need for retransmission.