Title :
Random access for a multibeam satellite with dynamic transponder switching
Author :
Wu, Cheng-Shong ; Li, Victor O K
Author_Institution :
Dept. of Electr. Eng., Univ. of Southern California, Los Angeles, CA, USA
fDate :
6/1/1989 12:00:00 AM
Abstract :
A multibeam satellite communications network serving multiple zones with S-ALOHA random access uplinks and dynamically switched transponders in the downlinks is studied. The overhead of switching transponders between zones may degrade the performance of the system significantly. Two different strategies are introduced and studied. In the guard time strategy, each slot time is equal to the packet transmission time plus the transponder switching time, allowing the transponder to be pointed to a new zone at the beginning of each slot. In the idle waiting strategy, each slot time is equal to the packet transmission time. If a transponder is switched to a new zone, it will take k slot time where k is the smallest integer greater than the switching time divided by the slot time. The throughputs of these two strategies are analyzed and compared
Keywords :
data communication systems; digital communication systems; multi-access systems; packet switching; probability; protocols; satellite relay systems; switching; transponders; S-ALOHA random access uplinks; downlinks; dynamic transponder switching; guard time strategy; idle waiting strategy; multibeam satellite communications network; multiple access system; multiple zones; packet transmission time; slot time; slotted ALOHA protocol; transponder switching time; Access protocols; Artificial satellites; Communication switching; Downlink; Frequency; Packet switching; Satellite communication; Throughput; Time division multiple access; Transponders;
Journal_Title :
Communications, IEEE Transactions on
