| 摘要 |
In a digital satellite communications system for communicating data between a HUB station (101) and a plurality of VSATs (Very Small Aperture Terminals) (102, 103, 104) or between the VSATs (102, 103, 104) via a communications satellite (107), each VSAT (102, 103, 104) comprises: a digital signal processing section (21) for demodulating signals received by the VSAT (102, 103, 104); ROM (24) for storing a default program (14) for letting the digital signal processing section (21) execute signal demodulation at start-up of the VSAT (102, 103, 104); rewritable memory (25) for storing an operation program (17, 113) for letting the digital signal processing section (21) execute signal demodulation after the start-up of the VSAT (102, 103, 104); an operation program download section (23) for obtaining the operation program (17, 113) by downloading the operation program (17, 113) from the HUB station (101); an error check/rewriting section (28) for conducting error check to the downloaded operation program (17, 113) until an errorless operation program (16, 17, 113) is obtained by the download and storing the errorless operation program (16, 17, 113) in the rewritable memory (25); and a switching control section (26, 29) for switching a program which is loaded into and used by the digital signal processing section (21) from the default program (14) to the operation program (16, 17, 113). <IMAGE> |
