A Priority-Aware Medium Access Control with Adaptive Overlapping Backoff for IoT Sensor Networks

Abstract

The rapid proliferation of IoT wireless sensor networks has intensified the demand for medium access control (MAC) protocols capable of simultaneously supporting concurrent multi-priority data services, low latency, and energy efficiency. Existing protocols, including TMPQ-MAC and PMME-MAC, struggle to adequately balance priority-aware contention management with scalable energy performance, particularly in large-scale deployments. In this paper, we propose the Overlapping Backoff Priority-based MAC (OBP-MAC) protocol, which introduces a novel priority-differentiated overlapping contention window mechanism that adaptively resizes backoff intervals according to packet priority level and collision history. OBP-MAC integrates duty cycling with RTS/CTS handshaking to coordinate channel access, ensuring that higher-priority transmissions consistently gain precedence while conserving energy during idle periods. Simulation results demonstrate that OBP-MAC significantly reduces collisions and communication latency, improves energy efficiency, and achieves higher packet success rates compared to TMPQ and PMME protocols under various network conditions. These results confirm that OBP-MAC substantially outperforms TMPQ-MAC and PMME-MAC in latency, energy efficiency, and delivery reliability, establishing it as a robust and scalable solution for multi-event IoT sensor networks.