New QoS resource allocation scheme using GTS for WPANs

IEEE 802.15.4 (low-rate Wireless Personal Area Networks-WPANs) [1] and IEEE 802.15.7 (Visible Light WPANs) [2] are one of the typical of WPANs which can support QoS through guaranteed time slots (GTS) mechanism to allocated a specific duration within a superframe structure for a TDM transmission. The low bandwidth utilization problem may occur in GTSs when the allocated bandwidth is less than the available one. However this problem is not solved thoroughly in standard and current researches. This paper analyses GTS performance in QoS transmission and proposes a new GTS allocation scheme named Unbalanced GTS allocation Scheme (UGAS) which can improves the bandwidth resource efficiency. UGAS approach will divide the CFP into different duration Time-Slots for different bandwidth requirement to minimize the underutilization. With the burst of traffic sources in multimedia visible light communication and QoS transmission in sensor network, the Network Calculus theory based on fluid model and Greedy algorithm are applied to solve the bandwidth underutilization problem. Compared with the standard GTS allocation scheme, it performs an efficient bandwidth allocation with QoS guarantee model and without breaks the standard protocol. The numerical results show that the proposed scheme is a promising approach for efficient resource allocation.