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Wireless Communications and Mobile Computing
Volume 2017 (2017), Article ID 9243019, 13 pages
Research Article

Congestion Detection and Alleviation in Multihop Wireless Sensor Networks

1Department of Electrical Engineering, COMSATS Institute of Information Technology (CIIT), Wah Cantonment, Pakistan
2Centre for Intelligent Signal and Imaging Research (CISIR), Department of Electrical and Electronics Engineering, Universiti Teknologi PETRONAS (UTP), Seri Iskandar, Malaysia
3Department of Computer Science, CIIT, Wah Cantonment, Pakistan

Correspondence should be addressed to Omer Chughtai; moc.liamg@iathguhc.ramu

Received 31 July 2016; Revised 21 December 2016; Accepted 24 January 2017; Published 26 February 2017

Academic Editor: Bernard Cousin

Copyright © 2017 Omer Chughtai et al. 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.


Multiple traffic flows in a dense environment of a mono-sink wireless sensor network (WSN) experience congestion that leads to excessive energy consumption and severe packet loss. To address this problem, a Congestion Detection and Alleviation (CDA) mechanism has been proposed. CDA exploits the features and the characteristics of the sensor nodes and the wireless links between them to detect and alleviate node- and link-level congestion. Node-level congestion is detected by examining the buffer utilisation and the interval between the consecutive data packets. However, link-level congestion is detected through a novel procedure by determining link utilisation using back-off stage of Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA). CDA alleviates congestion reactively by either rerouting the data traffic to a new less congested, more energy-efficient route or bypassing the affected node/link through ripple-based search. The simulation analysis performed in ns-2.35 evaluates CDA with Congestion Avoidance through Fairness (CAF) and with No Congestion Control (NOCC) protocols. The analysis shows that CDA improves packet delivery ratio by 33% as compared to CAF and 54% as compared to NOCC. CDA also shows an improvement in throughput by 16% as compared to CAF and 36% as compared to NOCC. Additionally, it reduces End-To-End delay by 17% as compared to CAF and 38% as compared to NOCC.