Electronic key telephone system

Details Electronic key telephone system Electronic key telephone system

1977-10-07

1979-07-03

Claffy, Kathleen H.

H04Q 520

Patent

active

041601319

ABSTRACT:
An electronic key telephone system is disclosed that provides a plurality of telephone features and functions, while only requiring a four-wire line between the central equipment and each key-set telephone (KST) and a two-wire line between the central equipment and each single-line telephone (SLT). Linear delta coding and time division multiplex (TDM) techniques are used to eliminate the multiple pairs required in traditional private business exchange (PBX) systems between the remote key telephones and the control unit. In the present system, a microprocessor controlled TDM controller transmits and receives control signals serially to and from interfaces in the system for control purposes and also for establishing exchange of digitized audio information data between selected interfaces. The system thus exchanges digitized audio information directly between interfaces and provides control signalling between the TDM controller and the interfaces, with all of the exchanges being done in real time. Among other things, the system is compatible with all types of existing central office exchange lines. The system may use combinations of single-line telephones (SLTs) or key-set telephones (KSTs). Specialized functions, such as conference calls, background music, external zone paging and night chime, as well as on-line maintenance, system configuration reprogramming, out-going telephone call control, and recordkeeping are available. To reduce complexity and increase economy, several functions in the system are time-shared, and the system is constructed in modular form to allow its capabilities to be tailored for its intended use.

REFERENCES:
patent: RE29078 (1976-12-01), Tate
patent: 3909550 (1975-09-01), Villadsen
patent: 3914559 (1975-10-01), Knollman
patent: 3935396 (1976-01-01), Barsellotti et al.
patent: 3967072 (1976-06-01), Dimmick et al.
patent: 3973085 (1976-08-01), Shiff
patent: 4024345 (1977-05-01), Kochem
patent: 4061887 (1977-12-01), Kasson et al.

Affiliated with

Also associated with

Rating

Electronic key telephone system does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Electronic key telephone system, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Electronic key telephone system will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2275703