MAP-MAC: A Priority-Based MAC Protocol for MAX Aggregation in Wireless Sensor Networks

MAX aggregation is a typical data aggregation operation in wireless sensor networks (WSNs). Due to energy constraints, MAX aggregation's low latency and energy efficiency are critical in emergency applications. As priority-based media access control (MAC) protocols can provide early channel access to high-priority traffic, assigning a higher priority level to data packets close to the MAX value can reduce the MAX value's delay. Since priority-based MAC protocols fail to offer success channel access strictly in descending order of priority, we still need to collect all data packets to obtain the accurate MAX value. Therefore, this article proposes a new priority-based MAC protocol for MAX aggregation (MAP-MAC), specially designed for cluster topology. MAP-MAC assigns the corresponding priority level to data packets according to the position of the data in the data range. Channel access priority is achieved by setting a corresponding starting clear channel assessment (CCA) detection in the time slot based on priority levels. This article analyzes the range of priorities and their impact on latency and energy consumption. The results show that MAP-MAC reduces the delay of the accurate MAX value by over 65% and energy consumption by over 70%, compared with the benchmark protocols. The analysis presented in this article is expected to provide a reference for setting the range of priorities and further improving the latency and energy consumption performance of WSNs.