A new GTS allocation schemes for IEEE 802.15.4

The IEEE802.15.4 standard provides beacon-enabled and non-beacon modes. In the beacon-enabled mode, which consists of Guaranteed Time Slots (GTS) allocated to individual devices by the network coordinator. The GTS is used by devices for cyclic data transmission and the coordinator can allocate GTS to a maximum of only seven, what is wrong, the bandwidth underutilization problem occurs in GTS when the used bandwidth is less than the available. In this paper, a new GTS scheme is presented to allow more devices to share the bandwidth within the same period. We divide the CFP into 32 equally sized slots and we have presented the new GTS scheme without introducing any changes in the frame format. The evaluation results show that the bandwidth utilization is improved.