Facsimile transmission over digital satellite land-mobile channels

摘要

The importance of facsimile communication over public telephonennetworks is evidenced by the rapid growth in the number of Group 3nfacsimile terminals. In this paper, the main characteristics of anreal-time approach are described whereby facsimile signals arendemodulated and their associated protocols are packetized and convertednby a Facsimile Interface Unit (FIU) to a format suitable forntransmission over digital land-mobile satellite channels. The FIUnconcept was developed to allow off-the-shelf facsimile terminals to beninterconnected via the PSTN through satellite networks and to permit thenprovision of enhanced user services, such as facsimile broadcastingn(point-to-multipoint) to mobile terminals, to be offered. In addition,nthe FIU concept is designed to mitigate for the longer access andntransport link delays encountered in mobile satellite systems