GTS size adaptation algorithm for IEEE 802.15.4 wireless networks

IEEE 802.15.4 standard specifies the Medium Access Control (MAC) and Physical (PHY) layer for wireless sensor networks (WSN) applications with limited power and low data rate. This standard supports time critical applications by allowing TDMA based access in beacon enabled networks. In these networks, the PAN coordinator exchanges data with the end devices through guaranteed time slots (GTS). The PAN coordinator can allocate GTS on a first come first serve (FCFS) basis in response to the requests by end devices. In original standard, the coordinator can assign up to the maximum seven GTSs. This fixed number of GTS allocation may result in inefficient utilization of channel bandwidth. In this paper, we propose a new GTS allocation scheme that will set the GTS size adaptively in accordance with the data size of the end device. We call it as GTS Size Adaptation Algorithm (GSAA) and it will optimally use the GTS resources. Simulations have been performed to validate the proposed GSAA.