Facsimile call success rates in long delay and impaired channel environments without collision detection

摘要

A facsimile transmission relay apparatus, referred to as an Intelligent Facsimile Relay (IFR) for improving call success rates in long delay environment such as terrestrial cellular, fixed wireless, and geostationary mobile satellite systems and the like. A first bi-directional telecommunications interface is provided for receiving facsimile signals from a transmitting facsimile device via a first network such as a Public Switch Telephone Network (PSTN). A buffer memory is used by the IFR for storing the facsimile signal, and a second bi-directional telecommunications interface retransmits the facsimile signal via the second network. An information processor is coupled to the second interface for monitoring messages from the receiving facsimile device and for generating messages to the receiving facsimile device to maintain communications integrity with the transmitting facsimile device via the networks using selective blocking of retransmitted commands for less sensitivity to the channel errors present in wireless applications, without the need for signal collision detection. The ultimate objective of the IFR design is to prevent call failures due to long delays and/or channel impairments by monitoring, buffering, relaying, replacing, and manipulating ITU-T T.30 signals as well as generating ITU-T T.4 fill patterns.