AGA: Adaptive GTS Allocation with Low Latency and Fairness Considerations for IEEE 802.15.4

IEEE 802.15.4 is a new standard uniquely designed for low-rate wireless personal area networks. It targets ultra-low complexity, cost, and power for low-rate wireless connectivity among inexpensive, portable, and moving devices. IEEE 802.15.4 provides a Guaranteed Time Slots (GTS) mechanism to allocate a specific duration within a superframe for time-critical transmissions. In this paper, we propose an adaptive GTS allocation (AGA) scheme for IEEE 802.15.4 with the considerations of low-latency and fairness. The scheme is designed based on the existing IEEE 802.15.4 medium access control protocol without any modification. A simulation model validated by the developed mathematical analysis is presented to investigate the performance of our AGA scheme. The capability of the proposed AGA scheme is evaluated by a series of experiments. It is shown that the proposed scheme significantly outperforms the existing IEEE 802.15.4 implementations.