SPEED-UNSYMMETRICAL NETWORK USING COMMUNICATION SATELLITE, AND GATEWAY DEVICE THEREFOR

摘要

A speed-unsymmetrical network using a communication satellite; specially, a speed-unsymmetrical network using a satellite-based high-speed line for a down line, and a ground low-speed line for an up line, wherein the low-speed line is effectively used as a backup line when a line failure is encountered. The network comprises a gateway device for controlling the connection-switching of the up and down lines in a communication between a center station and at least one remote station, and a monitor device for monitoring for abnormality in receiving data from the high-speed line by remote stations, wherein the monitor device informs, when an abnormal data reception by at least one of the remote stations is detected, the abnormal reception to the gateway device, and the gateway device thereby selects the low-speed line as a down line to the affected remote station.