Dynamic Super-Frame Adjustment in Cluster Topology Based IEEE 802.15.4 Networks

Abstract

The IEEE standard for Wireless Personal Area Network (WPAN) is IEEE 802.15.4 which aims to provide low data rate, low power consumption and a low-cost solution. It can support three topologies cluster tree, star and mesh. Another important feature which this standard can support is the low duty cycle operation which is most suitable for low power devices this is done because of a predetermined structure in beacon-enabled mode called the superframe structure. The superframe structure is mainly based on two parameters: The Beacon Order (BO) and the Superframe Order (SO). SO, defines the duty cycle of nodes, whereas BO defines the length of beacon interval (BI). These values play a key role in the network performance such as; network throughput, energy depletion and latency of communication. Due to fixed superframe parameters (both BO and SO) the network performance is greatly affected. In the existing work, a small number of research attempts are made to dynamically adjust super-frame parameters. Dynamic adjustment of super-frame BO and SO parameters is a problem in a cluster tree and star topology based IEEE 802.15.4 networks. In this research, we proposed Cluster Tree Superframe Duration Adjustment Algorithm (CTSDA) for cluster tree topology based IEEE 802.15.4 network. In CSTDA algorithm the PAN coordinator dynamically adjusts the SO parameter of cluster heads based on packet receive ratio, data rate, number of cluster heads and delay observed at cluster heads. Comprehensive simulation analysis of CTSDA is compared with the standard IEEE 802.15.4 and show better results in terms of latency, packet delivery ratio and throughput.