VC-GTS: Virtual Cut-Through GTS Allocation Scheme for Voice Traffic in Multihop IEEE 802.15.4 Systems

Supporting multimedia traffic is one of the major challenges for the next generation of wireless personal area networks (WPANs). Especially, the IEEE 802.15.4 WPAN standards specify how to guarantee real-time traffic with a type of time division multiple access (TDMA), called the guaranteed time slots (GTS). The GTS mechanism has led many researchers to design techniques aiming to support various real-time applications within the delay jitter. Since the IEEE 802.15.4 standards can operate at low data rate up to 250Kbps, it is limited to guarantee real-time multimedia traffic except voice. The voice traffic has bidirectional characteristics and may go through the multihop in WPAN which can support short-range communications among electronic devices. In this paper, we introduce a virtual cut-through GTS allocation mechanism, namely VC-GTS allocation, for voice traffic in multihop IEEE 802.15.4 systems. The proposed scheme can support bidirectional voice traffic and delivery the traffic to the destination through multihop paths with the minimum end-to-end delay time. The most important thing is that our proposed scheme achieves low delay time and packet error rate without a complex allocation algorithm in multihop IEEE 802.15.4 networks. Our simulation results show that our new scheme outperforms the basic IEEE 802.15.4 GTS mechanism.