GB1423126A - Adaptive addressing systems for airbourne data systems - Google Patents

Abstract

1423126 Selective signalling BENDIX CORP 20 Sept 1974 [7 Nov 1973] 41094/74 Heading G4H In a co-operative data system, messages from a master station to a remote station which has a relatively long address normally include a relatively short address assigned to the remote station; and the master station periodically transmits an " all call " directed to all remote stations within its sphere of influence which have not been assigned a relatively short address, such a remote station responding with its relatively long address, to which the master station responds in turn with a relatively short address and a truncated portion of the relatively long address, the remote station memorizing the relatively short address as its assigned address. The remote station signals its acceptance of the assigned address to the master station by sending it back. If this acceptance indication is not received by the master station, the latter repeats the assignment message, and if acceptance is still not indicated, removes this assignment from its memory. Routine messages in both directions between master and remote stations contain the assigned address and data. Data may also be included in the acceptance message. All messages also include a preamble (for synchronization), control bits indicating the type of message, and parity. The " all call " message includes an " all call " address. Each remote station includes receive and transmit shift registers with an address comparator associated with the former. The master station may be a ground station and the remote station may be aircraft, the relatively long address being addresses unique worldwide, and the relatively short addresses being unique within the sphere of influence of the ground station. Use in aircraft to satellite communications is also mentioned.