Priority-Oriented Adaptive GTS Allocation in IEEE 802.15.4 WSNs

Abstract

The IEEE 802.15.4 standard is known to be widely utilized in Wireless Sensor Networks (WSNs) for their time sensitive applications. However, the default contention-based MAC operations suffer from delays, resource wastage, etc. with heterogeneous dynamic traffic. Though some Guaranteed Time Slots (GTS) are offered, they make little to no use of adaptable allocation GTS strategies to improve the real-time operation of the network. This paper presents GTS Adaptive Priority-Based GTS Allocation Algorithm for the beacon enabled mode of IEEE 802.15.4. It allows better MAC-layer scheduling to improve differentiation and service facilitation for time-sensitive data. The performance of the algorithm was assessed through comparative analysis against the standard CSMA-CA operation in MATLAB simulations with the same topology and traffic distribution. Simulation results prove the predicted GTS allocation algorithm to significantly optimize the network performance across multiple performance metrics. The CSMA-CA algorithm provides data transmission rates of 29.9 and 40.0 (lower and upper bounds respectively). Proposed algorithm offers these same metrics at 92.6 and 94.3, respectively. The method proposed shows low packet loss irrespective of the communication range. On the contrary, CSMA-CA suffers from high packet loss under high traffic and poor channel conditions. With the results confirming that adaptive and priority-aware GTS allocation is a mechanism that improves throughput, reliability, and determinism at the MAC layer, it means that IEEE 802.15.4 networks can be utilized for real-time and high-throughput applications in WSNs.