Performance analysis of the IEEE 802.15.4 Wireless Sensor Network beacon enabled mode GTS allocation mechanism for real-time applications

Abstract

In the IEEE 802.15.4 Wireless Sensor Networks (WSNs), deterministic resource allocation is provided by using a Guaranteed Time Slot (GTS) mechanism for real-time application traffic in the beacon enabled mode. Real-time applications require high quality of service (QoS) sensitivity such as bounded end-to-end delay and low Bit Error Rate (BER). However the GTS mechanism requires careful parameter tuning for efficient network performance without jeopardising the energy consumption of the wireless nodes. This paper investigates the issue of power consumption and end-to-end delay trade-offs in the IEEE 802.15.4 beacon enabled mode. The optimum duty cycle can be determined for maximum power savings by the appropriate selection of Superframe Order (SO) and Beacon Order (BO) to conform to the latency required by the real-time application. Existing approaches assumed a fixed SO and BO. This work introduces the 3 dimensional (3-D) and 2 dimensional (2-D) surface chart methods for obtaining an efficient network dimensioning of an IEEE 802.15.4 WSN cluster. This work also demonstrates that queue management and buffer dimensioning at the nodes becomes a significant factor for better network performance.