Content based dynamic super-frame adjustment in star topology based IEEE 802.15.4 networks

Abstract

IEEE 802.15.4 standard is designed for low power wireless personal area networks (LRWPANs). It provides cheap wireless networking solutions with limited data rates and low power consumptions. In recent years, both industry and academia are attracted to IEEE 802.15.4 because of its applicability in wireless sensor networks (WSNs) and wireless body area sensor networks (WBANs). An important feature of IEEE 802.15.4 is the very low duty cycle operation to conserve sensor node’s energy. IEEE 802.15.4 uses a super-frame structure for the node’s duty cycle adjustment. The super-frame structure is based on two parameters: beacon order (BO) and super-frame order (SO). The performance of an IEEE 802.15.4 network depends on the values of BO and SO. These values depict the energy consumption, throughput, node discovery and latency of communication. IEEE 802.15.4 uses fixed BO and SO values which can be carefully chosen to meet the network requirements. In existing literature, few research efforts are made to dynamically adjust BO and SO based on network condition. However, the problem of dynamically super-frame adjustment is still an open research issue. In this research, we propose a content based dynamic super-frame adjustment algorithm (CDSA) for star topology based IEEE 802.15.4 networks. In CDSA, the PAN coordinator adjusts both BO and SO simultaneously based on different metrics: application data rate, receive ratio, number of PAN sources and observed delay. Detailed simulation analysis shows that CDSA is capable of meeting application’s content requirements by dynamically adjusting the super-frame structure. Overall, CDSA as compared to IEEE 802.15.4 provides lower energy consumption, higher network throughput and reduces the latency of communication.