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.
