Table of Contents
ISRN Sensor Networks
Volume 2012, Article ID 864694, 7 pages
Research Article

A New TDMA Scheduling Algorithm for Data Collection over Tree-Based Routing in Wireless Sensor Networks

School of Electrical Engineering, Iran University of Science & Technology, Tehran 16846 13114, Iran

Received 21 December 2011; Accepted 10 January 2012

Academic Editors: L. Reggiani and H.-H. Yen

Copyright © 2012 Vahid Zibakalam. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Data collection is one of the most important tasks in Wireless Sensor Networks (WSNs) where a set of sensors measure properties of a phenomenon of interest and send their data to the sink. Minimizing the delay of the data collection is important for applications in which certain actions based on deadline are needed, such as event-based and mission-critical applications. Time Division Multiple Access (TDMA) scheduling algorithms are widely used for quick delivery of data with the objective of minimizing the time duration of delivering data to the sink, that is, minimizing the delay. In this paper, we propose a new centralized TDMA scheduling algorithm that is based on nodes congestion for general ad hoc networks. In the proposed algorithm, the scheduling is obtained using colouring of the original network. Colouring the original network is accomplished based on congestion degree of nodes. The simulation results indicate that the performance of our algorithm is better than that of node-based and level-based scheduling algorithms. We will also show that the performance of our proposed algorithm depends on the distribution of the nodes across the network.