| The satellite channel in a SATCOM on-the-move system experiences outages due to channel blockage by buildings, trees, and other obstructions in the environment. An extensive measurement campaign was
conducted in the fall of 2004 to characterize this channel in a variety of locations and operating conditions. There are, however, limitations to these data sets and the models that were derived from them. All of the measurements are taken from the same satellite at locations that were within about 0.6 degree of latitude and 1.6 degrees of longitude. As a result, the measurements and models may be biased to these operating conditions. Measurements using satellites at
different locations in the sky are needed to generalize the results.
There are fewer satellites available than points of interest in the sky for development of a generalized blockage model. In this paper we
use a three-dimensional model of the buildings in Boston, MA, to estimate outage locations. Because multipath reception is essentially eliminated by the highly directional SATCOM antenna, optical methods such as ray tracing are used to determine outage locations for ground nodes. These shadowed locations are compared to measurements in Boston
during the previous measurement campaign. The channel blockage statistics obtained through measurement and simulation are also compared.
Using the verified simulation model, outage profiles are determined for arbitrary satellite locations. These simulations are used to generalize the blockage channel model for different elevation angles.
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| Matt Brennan worked with the Wideband Tactical Networking group at Lincoln Laboratory during the Summer of 2006. During this time, he focused primarily on blockage modeling for satellite communications on the move. He is currently a first-year graduate student at the University of Southern California under a Viterbi School of Engineering Dean's Fellowship. Matt's research interests include network information theory and cooperative networking. In May 2006, he received B.S. degrees in Electrical Engineering and Computer Systems Engineering from the University of Massachusettes at Amherst.
Dr. W. Mark Smith joined the technical staff in the Wideband Tactical Networking Group at MIT Lincoln Laboratory in 2004. In this position, he conducts research in satellite communications on the move. His research interests include cooperative networking and channel measurements and modeling. Prior to joining the group, he was at
Stanford University and pursued research in propagation models for terrestrial wireless communication systems in urban environments. From 1993 to 1997 he served as a space launch systems engineer in the U. S. Air Force at Vandenberg Air Force Base, California. Dr. Smith received the B.S. degree in electrical and computer engineering from
Carnegie Mellon University in 1993 and M.S. and Ph.D. degrees in electrical engineering from Stanford University in 1999 and 2004, repectively.
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