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Investigation of Fixed Satellite Link with LifeLink™ System, 10-9091

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Principal Investigators
E. Sterling Kinkler
Scott J. Schneider

Inclusive Dates: 04/19/99 - 8/19/99

Background - The nation’s crowded highways and streets are becoming increasingly dangerous to travel. The Intelligent Transportation Systems (ITS) initiatives proposed by the U.S. Department of Transportation provide methods for increasing the throughput and safety on these roadways without expanding the physical infrastructure. A key ITS focus is aimed at quicker notification of, and response to, roadway incidents that result in serious injuries or loss of life. To adequately serve remote scenes, mobile, emergency response links are necessary. In this effort, the Institute is working to attract sustaining support by the Texas Department of Transportation (TxDOT), multiple other state departments of transportation, and the Federal Highway Administration's ITS program. This support, along with that from several private companies providing satellite terminal equipment and support, will aid in the development of an integrated, autonomous, practical, rapidly deployable, mobile terminal for remote incident management. This project investigated and demonstrated the feasibility of integrating the existing LifeLink™ application into a satellite network for remote emergency management and control.

Approach - A satellite using spot-beam technology was investigated to determine the feasibility of supporting the LifeLink communications data rate [near T1, approximately 1.445 megabytes per second (Mbps)] using relatively small ground terminal equipment. Using a satellite link for this data path subjects the system to a large latency (500 milliseconds) common to Geostationary Earth Orbit (GEO) satellites. These issues and others were investigated in this project. The NASA Advanced Communications Technology Satellite (ACTS) is currently the only GEO satellite with the necessary spot-beam technology capable of providing T1 data rates. SwRI is currently supported by a Space Act Agreement (SAA) with NASA, which permits SwRI access to satellite time for testing, as well as the use of NASA’s satellite dish-antenna terminals. Under this SAA, the performance of the LifeLink™ applications over the satellite link was tested. The test included the measurement of audio, video, and data packets lost during communications, their associated measured data rates, and subjective measurements of the audio and video quality.

Accomplishments - The initial tasks involved testing the LifeLink™ system across a simulated satellite channel in a SwRI laboratory environment. The system was then tested using a live satellite channel at NASA’s Glenn Research Center in Cleveland, Ohio. The tests involved using the LifeLink™ system in both a wired and wireless configuration. The wireless configuration used a 2.4-gigahertz spread-spectrum link for the communications between the satellite antenna and the ambulance node of the LifeLink system. The tests successfully demonstrated the ability to transmit video, audio, and data across a satellite channel at 1.544 Mbps (T1 rate) with very high quality and reliability. The successful completion of this project has also resulted in TxDOT funding for development of a prototype incident management trailer.

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