Quick Look
Investigation of Fixed Satellite Link
with LifeLink System, 10-9091
Printer Friendly Version
Principal Investigators
E. Sterling Kinkler
Scott J. Schneider
Inclusive Dates: 04/19/99 - 8/19/99
Background - The nations 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 NASAs 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
NASAs 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.
Electronic Systems and
Instrumentation Program
1999 IR&D Home
SwRI Home
|