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Journal of Computer Networks and Communications
Volume 2011, Article ID 195685, 19 pages
Research Article

Alert: An Adaptive Low-Latency Event-Driven MAC Protocol for Wireless Sensor Networks

1Department of Electical Engineering and Computer Science, Wichita State University, Wichita, KS 67260, USA
2Research and Technology Center, Robert Bosch Corporation, Palo Alto, CA 94304, USA

Received 18 March 2011; Accepted 29 August 2011

Academic Editor: Eduardo Da Silva

Copyright © 2011 Vinod Namboodiri and Abtin Keshavarzian. 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.


Collection of rare but delay-critical messages from a group of sensor nodes is a key process in many wireless sensor network applications. This is particularly important for security-related applications like intrusion detection and fire alarm systems. An event sensed by multiple sensor nodes in the network can trigger many messages to be sent simultaneously. We present Alert, a MAC protocol for collecting event-triggered urgent messages from a group of sensor nodes with minimum latency and without requiring any cooperation or prescheduling among the senders or between senders and receiver during protocol execution. Alert is designed to handle multiple simultaneous messages from different nodes efficiently and reliably, minimizing the overall delay to collect all messages along with the delay to get the first message. Moreover, the ability of the network to handle a large number of simultaneous messages does not come at the cost of excessive delays when only a few messages need to be handled. We analyze Alert and evaluate its feasibility and performance with an implementation on commodity hardware. We further compare Alert with existing approaches through simulations and show the performance improvement possible through Alert.