WirArb: A New MAC Protocol for Time Critical Industrial Wireless Sensor Network Applications

Wireless sensor networks are typically designed for condition monitoring applications and to conserve energy but not for time-critical applications with strict real-time constraints that can be found in the industrial automation and avionics domain. In this paper, we propose a novel medium access control (MAC) protocol defined as wireless arbitration (WirArb) which grants each user channel access based on their different priority levels. The proposed MAC protocol supports multiple users and each user is pre-assigned a specific arbitration frequency which decides the order of channel access. With this mechanism, we can ensure that the user with the highest priority will immediately gain channel access and we can guarantee a deterministic behavior. To evaluate the proposed MAC, we use a discrete-time Markov chain model to mathematically formulate the WirArb protocol. Our results show that the proposed protocol provides high performance to ensure deterministic real-time communication and bandwidth efficiency.