Alcatel Transmission Par Faisceaux Hertziens A.t.f.h.

Marc Pontif

Philippe Sadot

Marc Darmon

A go-back-N automatic repeat request method for use on a duplex installation having noisy return channels. When an acknowledge signal (ACK) is not correctly received, it is assumed to be positive until the Nth successive incorrectly received acknowledgement, which is treated as a negative acknowledgement, thereby ensuring that blocks are repeated even if acknowledgements are degraded by jamming.

Method of automatically requesting retransmission in a duplex digital

Enough room is provided in a transmitted frame to receive a plurality (n) of useful information blocks, thereby making it possible to catch up any excessive lateness (r) which may arise due to successive repeats. The decoder (2) provides a confidence flag (3) to the controlling microprocessor (5). The command block (COM) from the decoder includes an indication of the number of useful blocks that are transmitted in the frame. This block is advantageously applied to an HDLC component (8).

Growing community of inventors

Villennes Sur Seine, France

Marc Pontif