Real-Time Deployment of Mesh Networks

Overview The goal of real-time deployment is the rapid establishment of a wireless mesh network to support communications in hard-to-reach areas. Intended applications are primarily emergency response communications in areas where traditional wireless solutions are problematic: inside large buildings, underground tunnels and mines, and urban canyons. Beyond two-way communications, ancillary services may include location tracking of emergency responders, environmental sensing, and physiological sensing of responders. In a typical scenario, a first responder (FR) equipped with a two-way radio and several small relay nodes enters a building. As the FR goes further into the building, the radio signal from incident command (IC) weakens. Before losing radio connectivity with IC, a relay node is deployed, providing two-hop connectivity between the FR and IC. This process repeats whenever any FR is about to lose radio signal, creating a multi-hop mesh network in real time to maintain connectivity with IC. NIST work on real-time deployment of mesh networks is focused in three areas: Link Quality Measurement to support rapid assessment of wireless mesh links Modeling and Simulation of mesh networks and real-time deployment protocols Prototyping, Testing and Evaluating implementations of rapidly-deployable mesh networks Related Work

Link Quality Measurement

Link quality measurement is needed by the deployment protocol to determine when a new node needs to be added to the network to maintain connectivity as it expands. Of utmost importance to efficient deployment of mesh network resources is detecting the onset of a marginal link before it occurs. NIST is studying various approaches to rapid and efficient measurement of the reliability of time-varying links in packet-switched wireless networks.

Modeling and Simulation

NIST is developing models and simulation tools to evaluate the performance of mesh networks and deployment protocols in RF-challenging environments. Specific efforts include:

• Modeling real-time deployment of indoor mesh network nodes
• Modeling wireless mesh network performance in underground mines
• Modeling TCP performance in mesh networks with cognitive radios

Prototyping, Testing, and Evaluation

NIST has developed two prototypes demonstrating real-time deployment of a multihop wireless network between a fixed incident command station and a mobile user:

1. 900 MHz system based on TinyOS motes
2. 2.4 GHz system based on IEEE 802.11

These systems have been used for testing, evaluation and feasibility analysis.

Related Work

Real-time Deployment

• J. Q. Bao and W. C. Lee, "Rapid deployment of wireless ad hoc backbone networks for public safety incident management," in Proc. IEEE Globecom, November 2007.
• D. Naudts, S. Bouckaert, J. Bergs, A. Schoutteet, C. Blondia, I. Moerman, P. Demeester, "A wireless mesh monitoring and planning tool for emergency services," in Proc. Workshop on End-to-End Monitoring Techniques and Services (E2EMON '07), May 2007.
• S. F. Midkiff and C. W. Bostian, "Rapidly-deployable broadband wireless networks for disaster and emergency response," presented at First IEEE Workshop on Disaster Recovery Networks (DIREN '02), June 24, 2002, New York City, NY.

Link Quality Measurement

• A. Wapf and M. R. Souryal, "Measuring indoor mobile wireless link quality," to appear in Proc. IEEE International Conference on Communications (ICC), June 2009.
• M. R. Souryal, L. Klein-Berndt, L. E. Miller, and N. Moayeri, "Link assessment in an indoor 802.11 network," in Proc. IEEE Wireless Communications Networking Conference (WCNC), April 2006.

Prototyping, Testing, and Evaluation

• A. Wapf, "Platform migration and performance enhancements of the lifeline prototype," Semester Thesis, ETH Zurich, September 2007.
• J. Geissbuehler, "Wireless multihop communications for first responder connectivity," Master Thesis, ETH Zurich, Summer 2006.

Related Efforts

• DARPA LANdroids program

Publications

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