Feasibility of international transport communications system

A satellite system that efficiently handles transmissions of short telex and data messages to and from simple and inexpensive terminals is found to be the least complex solution. It is noted that the Trucksat system requires a satellite transponder complexity similar to that in the maritime satellite system and a mobile terminal that is moderately more complex than a terrestrial mobile radio. A single pair of 25-kHz radio channels could service thousands of trucks. It is desirable that the system data rate over the radio link be at least 1200 b/s. A random access arrangement of the slotted ALOHA type is proposed. It is pointed out that packet collisions and transmission errors will be handled by error detection control and retransmission with a randomized delay.