Optimal GTS distribution to heterogeneous sensors in IEEE 802.15.4 network for healthcare monitoring applications

In the Low Rate Wireless Personal Area Networks (LR-WPANs), such as Wireless Body Area Networks (WBANs), the tiny sensors implanted in human bodies generate heterogeneous physiological traffic which in turn needs to be sent to the gateway nodes in real-time. The beacon-enabled mode of IEEE 802.15.4 MAC protocol is considered suitable for such types of networks because of its unique Guaranteed Time Slots (GTSs) mechanism. However, Personal Area Network (PAN) coordinator of IEEE 802.15.4 MAC uses a static First-Come-First-Served (FCFS) mechanism to allocate GTSs. This kind of biased and static allocation of GTSs results in poor utilization of the available bandwidth, thus preventing from the real-time data delivery of the sensor packets to the destination. In order to alleviate this problem, we in this paper, propose a novel and effective means of GTS allocation for WBANs, called Dynamic Distribution of GTS Scheme (DDGS) protocol in which the contending nodes are granted GTS slots on a priority basis purely decided by the real-time nature of the traffic in the sensor field. Through extensive simulations, we show that our proposed DDGS protocol significantly outperforms the static allocation of the limited and available contention free slots in respect of bandwidth utilization, network throughput and end-to-end latency without consuming significant energy of sensor nodes. © 2021, The Author(s), under exclusive licence to Springer-Verlag London Ltd., part of Springer Nature.