The system is one of two federally funded advanced research and development programs that L-3 has designed to enhance coal mine safety. The second is an ultra wideband-based, real-time location tracking system that would help rescuers more precisely locate miners inside a mine. Both programs are designed to meet requirements outlined in the 2006 federal law known as the MINER Act, which increased safety standards for mines.

This past October, a House committee passed the Supplemental Mine Improvement and New Emergency Response Act, which builds on the initial MINER Act. The measure calls for the government to study better technology for mine communication and tracking systems for miners trapped underground.

L-3's system will be able to integrate with existing wired mine communications systems, Erndle said. Communications systems now used by mines often consist of a cable that emits and receives radio waves. Those systems have a limited range, due to the high frequency signal they require. Higher frequency transmissions cannot pass through solid rock, which limits the systems to a line of sight application similar to an FM radio signal.

L-3's wireless system is not the only mesh technology currently available, but L-3 is unique in its use of transmission nodes. A Canadian firm, Active Control Technology Inc., has also developed wireless technology aimed at improving underground mine safety.

Active Control's system provides two-way wireless voice communications, tracking and data for mines through a wi-fi network. The system has the ability to transport streaming data such as voice and video over multiple wireless feeds.

In recent years, coal mine safety has come under intense scrutiny in the wake of numerous fatal incidents. Federal statistics show last year was the second deadliest since 2002 for U.S. coal miners. The Mine Safety and Health Administration (MSHA) reported 32 miners died on the job in 2007, including six miners who were trapped after a collapse at the Crandall Canyon Mine in Utah. Three rescuers died a few days later in an attempt to reach them.

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