Telephonic communications – Subscriber line or transmission line interface
Patent
1996-12-27
1999-02-16
Hong, Harry S.
Telephonic communications
Subscriber line or transmission line interface
379377, 379398, 379413, H04M 300
Patent
active
058728422
ABSTRACT:
A communication loop using a subscriber line interface circuit (SLIC) is modified such that it can operate in unbalanced ringing environments as well as balanced ringing environments. This is accomplished by grounding the tip lead of a telephone instrument and creating an open circuit at the tip lead of the SLIC. The ring lead of the telephone instrument and the ring lead of the SLIC are electrically connected, and an AC voltage applied to the ring lead by the SLIC is increased. A power supply is connected to the SLIC and biased to provide the increased AC voltage on the SLIC ring lead while the average voltage on the SLIC tip lead is maintained substantially at ground. The result of this circuitry is a trapezoidal signal meeting the amplitude, loading and crest factor requirements of Bellcore Technical Requirement Publications TA-NWT-000909 and TR-NWT-000057.
REFERENCES:
patent: 4468541 (1984-08-01), Cohen
patent: 4860332 (1989-08-01), Chism
patent: 4922517 (1990-05-01), West, Jr. et al.
patent: 4996702 (1991-02-01), Gray
patent: 5140631 (1992-08-01), Stahl
patent: 5329585 (1994-07-01), Susak et al.
patent: 5422949 (1995-06-01), Tsukagoshi
patent: 5515417 (1996-05-01), Cotreau
patent: 5515434 (1996-05-01), Cotreau
patent: 5517565 (1996-05-01), Cotreau
patent: 5521974 (1996-05-01), Hayashi et al.
patent: 5544241 (1996-08-01), Dibner et al.
patent: 5619567 (1997-04-01), Apfel
patent: 5659570 (1997-08-01), Cotreau et al.
patent: 5694465 (1997-12-01), Apfel
patent: 5706336 (1998-01-01), Kikinis
Bellcore Technical Requirement Publication, TA-NWT-000909 Issue 2, Dec. 1993, Section 4, "Generic Requirements and Objective for Fiber in the Loop System".
Bellcore Technical Requirement Publication, TR-NWT-000057, Issue 2, Jan. 1993, "unctional Criteria for DLC Systems".
Caine Steven L.
Daly William G.
Barnhardt III Hubert J.
Gardner Kelly A.
Hong Harry S.
Massaroni Kenneth M.
Saint-Surin Jacques M.
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