Interconnecting Danube networks through satellite links

Studies to be performed by the French NADIR project on techniques to interconnect Danube local-area networks via the Telecom-1 satellite communications system are described. Danube links up to 256 stations by coaxial cable at a predicted rate of 1.8 Mbit/sec in CSMA/CD mode and offers both connectionless and connection-oriented service; Telecom 1 (as simulated by ANIS) provides call-per-call or semipermanent TDMA simplex or full-duplex linkage (point-to-point or multipoint) at 2.4-2000 kbit/sec with a delay of 300 msec and a bit error rate (BER) lower than 10 to the -6th 99 percent of the time (or 10 to the -10th with forward-error correction). The problems of routing, error control, and flow control are considered. A simple scheme involving routing by filtering the address fields, no error and flow control, and minicomputers as gateways in each Danube system is chosen for the point-to-point simulations, while the multipoint connections will be made receiver half-gates and single sender half-gates at each Danube system. Block diagrams are provided.