Facsimile store and forward system with local interface

Abstract

A local router interface couples a conventional facsimile device to the public switched telephone network (PSTN) to communicate with a remotely located facsimile store and forward facility (F-SAFF) to perform a host of improved facsimile service methods, including a never no answer or busy send (NNABS) method, a never no answer receive (NNAR) method, a private facsimile method, a will call facsimile method, a pager facsimile method, a facsimile mail method, a facsimile information retrieve method, a facsimile information send method, a facsimile cover method, a facsimile speed cover method, a facsimile broadcast method, a facsimile flexible broadcast method, a facsimile access restriction method, a facsimile conversion method, an urgent facsimile method, and a facsimile addition method. Innocuous call progress monitoring with fast busy detection, post-fax line holding, F-SAFF-to-remote and remote-to-F-SAFF bridging are provided. The router includes detectors for loop-current, ring signals, call progress signals, precise busy signals, dual tone multi-frequency (DTMF) signals, and modulated data signals, as well as generators for going off-hook, generating and transmitting DTMF signals and modulated data signals over a wall phone line as well as ring and dial tone signals through an adjustable amplifier circuit and a subscriber line interface circuit to a fax telephone line. A switching connection circuit is also included for selectively connecting the wall phone line to the fax phone line and for selectively connecting other components of the telephony interface thereto.

Dependencies are inferred from the claim text.