A Taxonomy for MAC Protocols in Wireless Sensor Networks Based on Traffic Prioritization

Abstract

Various media access control (MAC) protocols have been developed to deal with the heterogenous traffic in wireless sensor networks (WSN). In many emerging applications, it is regarded essential to prioritize the heterogeneous traffic for reliable performance of WSN. This work categorizes the recently developed traffic prioritization MAC protocols in the classes of ‘Adaptive Contention’, ‘Duty-Cycle Adaptation’, ‘Queue Management’ and ‘Hybrid’. A taxonomy has been developed based on the categorization and detailed overview of each protocol is presented. The performance benefits and gaps are described for each of the protocols and the future research directions are suggested based on the analysis. It has been identified that most of the existing MAC protocols, although provide early channel access to high priority traffic, fail to offer true preemptive priority. There exists no mechanism which could pause/interrupt the ongoing transmission of the low priority traffic to facilitate the immediate channel access for high priority data. The analysis provided by this article is expected to aid the future researchers in identifying the trends of MAC protocol development in the context of traffic prioritization.