Survey on MAC protocols for heterogenous traffic in Wirelass sensor networks

Abstract

Wireless Sensor Networks (WSNs) consists of multiple sensor nodes, which are deployed randomly to collect periodic data, processes the data and forward it to the sink node. The main challenges that WSN faces are severe energy constraints, unpredictable environmental conditions, robustness, responsiveness, self-configuration, etc… Among this the main challenge is the energy efficiency.  In order to tackle all these challenges, new protocols in all the layers of communication stack need to be designed. Designing a MAC protocol is of crucial importance because it influences the transceiver unit of the sensor node. The Quality of Service (QoS) at the MAC layer matters as it rules medium sharing and supports reliable communication. In WSNs nodes generate heterogeneous traffic which have different QoS requirements like reliability and delay deadline with different priority requirements that vary according to the application. In this work, a variety of MAC protocols for WSNs are surveyed, with a special focus on traffic classification and priority assignment. A comparison of different MAC protocols with various parameters and future research directions are also included.