Key telephone system without common control

Details Key telephone system without common control Key telephone system without common control

1995-12-28

1998-07-28

Chin, Stephen

Pulse or digital communications

Transceivers

Modems

375219, 370278, H04B 138, H04L 516

Patent

active

057871159

ABSTRACT:
A multi-line key telephone system not having a key service unit includes three analog telephone lines to which up to eight, three-line telephones may be connected to provide enhanced service features with cost-effectiveness. System reliability is maintained, notwithstanding the power dependency of the telephones, by including POTS telephones to provide uninterrupted essential telephone service in the event of a power outage. Both data and voice communications between two or more of the three-line telephones is achieved by converting an input digital bit stream from either a digital or analog source into a corresponding out-of-band binary FSK radio frequency output signal that is transceivingly communicated between the three-line telephones as data packets within a TDM frame. The out-of-band signal thus permits analog voice communications on the same line to proceed without interference. A telephone initiating a communications session acts as a master station, establishing inter-station communications synchronous at the frame level and asynchronous at the packet level. The called telephone functions as a slave station in a second time slot synchronized to a first time slot in the TDM frame received from the master. Temporary storage of data in firmware buffers and controlled timing at both the master and slave permits these stations to function within their respective TDM frame time slots.

REFERENCES:
patent: 4068198 (1978-01-01), Otto
patent: 4488120 (1984-12-01), Carsten
patent: 4538136 (1985-08-01), Drabing
patent: 4567603 (1986-01-01), Howell et al.
patent: 4633425 (1986-12-01), Senderowicz
patent: 4670888 (1987-06-01), Smith III
patent: 4691342 (1987-09-01), Waldron et al.
patent: 4724534 (1988-02-01), Guzman-Edery et al.
patent: 4766599 (1988-08-01), Miyazaki
patent: 4825448 (1989-04-01), Critchlow et al.
patent: 5014285 (1991-05-01), Basile et al.
patent: 5054034 (1991-10-01), Hughes-Hartoss
patent: 5124698 (1992-06-01), Mustonea
patent: 5130676 (1992-07-01), Mutz
patent: 5329258 (1994-07-01), Matsuura
patent: 5416779 (1995-05-01), Barnes et al.
patent: 5555276 (1996-09-01), Koenck et al.
patent: 5648993 (1997-07-01), Kawada
patent: 5657344 (1997-08-01), Na

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