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US4394756A Expired / Lapsed US ⏱️ 0.0 years remaining

Generation of busy signals in a digital concentrator

Assignee: AT&T Inc
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Filing: 1980-09-12
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Granted: 1983-07-19
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Expires: 2000-09-12
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Abstract

Abstract A digital concentrator system for use with a plurality of digital carrier systems in the telephone subscriber loop plant is disclosed. The concentrator system comprises a central office terminal (110), a remote terminal (102), and an interconnecting digital carrier path (108). In the transmit direction at each terminal (110,112), a plurality of multiplexed encoded signal streams are demultiplexed and the encoded signals stored. A selected number of encoded signals are retrieved and multiplexed for transmission to a distant terminal (112,110) as a concentrated pulse stream (123,175). In the receive direction at each terminal (110,112), the encoded signals in the multiplexed concentrated stream (125,177) are demultiplexed and stored. The stored encoded signals are retrieved and the original number of encoded signal streams derived for transmission to the carrier terminal (100,102). Supervisory and control communication between the two concentrator terminals (110,112) is achieved by way of data messages on a derived data link. Operation between the transmit and receive directions at each terminal is asynchronous and controlled by a microcomputer (124,160). When all talking paths are in use through the concentrator system, a fast-busy encoded signal is multiplexed with other encoded signals and transmitted to the carrier terminal (100,102).

Inventors

  • 👤 Ronald J. Canniff

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-27 13:48
CPC Classifications
H; H04; H04Q; H04Q11/00; H04Q11/04; H04Q11/0407

Claims Analysis

Total Claims: 8
Claim 1
Independent Claim 92 words
A method of transmitting a busy signal to a calling party when all paths are busy through a digital switching system utilizing successive frames of selectively assigned time slots, said method characterized by the steps of transferring a busy code word from a table to a line-to-trunk assignment device (810) storing a busy status signal in said assignment device to each newly active line when all paths through said switching system are in use, and using said busy status signals to transfer said busy code word to each said newly active line.
Claim 2
Independent Claim 92 words
A method of transmitting a busy signal to a calling party when all paths are busy through a digital switching system utilizing successive frames of selectively assigned time slots, said method characterized by the steps of transferring a busy code word from a table to a line-to-trunk assignment device (810) storing a busy status signal in said assignment device to each newly active line when all paths through said switching system are in use, and using said busy status signals to transfer said busy code word to each said newly active line.
Claim 3
Dependent Claim 39 words
The method of transmitting a busy signal according to claim 1 further characterized by the step of transferring said busy code word from said assignment device (810) to a temporary holding register (826) at the beginning of each frame.
Claim 4
Dependent Claim 54 words
The method of transmitting a busy signal according to claim 2 further characterized by the steps of sequentially reading each busy status signal from said assignment device (810), and substituting said busy code word from said holding register (826) for each line code in said assignment device (810) corresponding to said newly active lines.
Claim 5
Dependent Claim 58 words
The method of transmitting a busy signal according to claim 3 further characterized by the step of sequentially reading line code words from said assignment device (810), including said busy code words, multiplexing said code words into a plurality of streams of code words, and transmitting said streams of code words to a plurality of line units (114,116).
Claim 6
Dependent Claim 112 words
Means for transmitting a digital busy signal from a digital concentrator terminal (110) to a plurality of line units (114,116) in successive frames of selectively assigned time slots, characterized by means (124) for storing a table of busy code words, means (124) for assigning a busy status state to each newly active line when all concentrator trunks are busy, means (810) responsive to said assigning means for storing a plurality of busy trunk-to-line assignment words, means (826) for selecting successive ones of said busy code words in said successive frames, and means (810) for storing said busy code words in line code storage locations (810) according to said busy trunk-to-line assignment words.
Claim 7
Dependent Claim 112 words
Means for transmitting a digital busy signal from a digital concentrator terminal (110) to a plurality of line units (114,116) in successive frames of selectively assigned time slots, characterized by means (124) for storing a table of busy code words, means (124) for assigning a busy status state to each newly active line when all concentrator trunks are busy, means (810) responsive to said assigning means for storing a plurality of busy trunk-to-line assignment words, means (826) for selecting successive ones of said busy code words in said successive frames, and means (810) for storing said busy code words in line code storage locations (810) according to said busy trunk-to-line assignment words.
Claim 8
Dependent Claim 59 words
Means for transmitting a digital busy signal according to claim 5 further characterized by means (820) for sequentially retrieving line code words from said line storage locations (810), means (806,818) for multiplexing said line code words including said busy code words for transmission as a plurality of multiplexed streams of code words to said plurality of line units (114,116).

References Cited (Backward Citations)

US3917908A Cited
US4256926A Cited
US4171466A Cited
US4327436A Cited
US4297532A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1986-07-18 1987-01-17 1987-07-19 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1990-07-18 1991-01-17 1991-07-19 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1994-07-18 1995-01-17 1995-07-19 $7700.00 Window Closed / Lapsed

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