Adaptive GTS allocation scheme to support QoS and multiple devices in 802.15.4

This paper specifies adaptive GTS allocation scheme for QoS support and supporting multiple devices with minimizing the waste of channel bandwidth in IEEE 802.15.4 networks. In the current superframe structure defined in IEEE 802.15.4 networks, the number of available guaranteed time slots (GTS) is limited to 7 and the channel bandwidth may be wasted with the increment of superframe order (SO). In the proposed scheme, we extend the superframe structure to increase the number of GTS to support QoS of multiple devices and to minimize the waste of channel bandwidth, even though SO value is increased. We analyze the performance efficiency between IEEE 802.15.4 MAC and the proposed scheme and evaluate the proposed scheme.