Call detection control apparatus

• US 5,416,832 A
• Filed: 06/04/1993
• Issued: 05/16/1995
• Est. Priority Date: 06/05/1992
• Status: Expired due to Fees

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Sasaki, Takeshi, Ikeda, Tooru, Kobayashi, Toshikatsu, Nitta, Toshio
• Primary Examiner(s): Dwyer, James L.
• Assistant Examiner(s): Wolinsky, Scott
• Application Number:
  US08/071,777
• Time in Patent Office: 711 Days
• Field of Search: 379/377, 379/378, 379/383, 379/384, 379/279, 379/273, 379/274, 379/190, 379/164, 379/165, 379/156, 379/413, 379/379, 379/270, 379/16, 379/15, 379/323, 379/324, 379/162, 358/86
• US Class Current: 379/190
• CPC Class Codes: H04M 3/005 Interface circuits for subscriber lines current supply H04M19/00 and subgroups; supervisory, monitoring or testing arrangements H04M3/22 and subgroups; in key telephone systems H04M9/006
• CPC Class Codes: H04M 3/2272 Subscriber line supervision circuits, e.g. call detection circuits

Abstract

A call detection control apparatus includes individual call detecting circuits, a common call detecting circuit, switching circuits, and a power supply circuit. The individual call detecting circuits individually detect call signals, which originate from telephone subscriber lines. The common call detecting circuit commonly detects call signals, which originate from the respective telephone subscriber lines. The switching circuits switch the respective telephone subscriber lines from the common call detecting circuit to the respective individual call detecting circuit when the common call detecting circuit detects an call signal from one of the respective telephone subscriber lines. The power supply circuit supplies operating power to each of the individual call detecting circuits upon interlocking with an operation of a corresponding one of the switching circuits.

Claims

1. A call detection control apparatus for controlling the detection of call signals originating through telephone subscriber lines connected with individual telephone subscriber terminals, the apparatus comprising:

a plurality of individual call detecting means for detecting respective call signals originating from corresponding telephone subscriber lines;

common call detecting means for simultaneously detecting call signals originating from the respective telephone subscriber lines, the common call detecting means being connected to all the telephone subscriber lines when a call signal is not detected by said common call detecting means;

a plurality of first switching means associated with respective individual call detecting means for switching the telephone subscriber lines from said common call detecting means to the corresponding individual call detecting means when said common call detecting means detects a call signal originating from at least one of the telephone subscriber lines; and

power supply means for supplying power to said common call detecting means, and for supplying operating power to each of said individual call detecting means only when said common call detecting means detects the call signal originating from at least one of the telephone subscriber lines.

2. An apparatus according to claim 1, wherein the power supply means comprises a plurality of individual power supply means for supplying power from said power supply means to respective individual call detecting means in response to a call detecting signal from said common call detecting means,

and the apparatus further comprising means for restoring to initial states those first switching means of said plurality of first switching means and those individual power supply means of said plurality of individual power supply means that are associated with individual call detecting means which do not detect a call signal when the telephone subscriber lines are switched from said common call detecting means to the individual call detecting means.

3. An apparatus according to claim 2, wherein said common call detecting means comprises timer means for counting a predetermined period of time, which starts when said common call detecting means detects said call signal, and for providing an output so that said individual power supply means and said first switching means, associated with said individual call detecting means which did not detect a call signal, are restored to said initial states.

4. An apparatus according to claim 3, wherein said timer means is a signal holding circuit for holding a call detecting signal from said common call detecting means for a predetermined period of time.

5. An apparatus according to claim 3, further comprising means for holding an operation of each of said individual power supply means and an operation of each of said first switching means by a call detecting signal from a corresponding one of said individual call detecting means until an off-hook state is ended.

6. An apparatus according to claim 1, further comprising subscriber line test means for selectively performing a line state test of each of the telephone subscriber lines, and second switching means for further switching a common test connection path, switched by said first switching means, to said common call detecting means and said subscriber line test means, so that each of the telephone subscriber lines is connected to said common call detecting means through said first and second switching means during a period other than a subscriber line test period.

7. An apparatus according to claim 6, further comprising means for connecting, during the subscriber line test period, each of the telephone subscriber lines which are not tested to corresponding one of said individual call detecting means through said first switching means, and for connecting one of the telephone subscriber lines which is tested to said subscriber line test means through said first and second switching means.

8. An apparatus according to claim 1, wherein said first switching means comprise relays for connecting all of said telephone subscriber lines to said common call detecting means when the call signal is not detected by said common call detecting means, and to said corresponding individual call detecting means when the call signal is detected by said common call detecting means.

9. An apparatus according to claim 2, wherein said individual power supply means comprise relays for connecting said power supply means to said respective individual call detecting means when the call signal is detected by said common call detecting means.

10. A call detection control apparatus for controlling the detection of call signals originating through telephone subscriber lines connected with individual telephone subscriber terminals, the apparatus comprising:

a plurality of individual call detecting means for detecting respective call signals originating from corresponding telephone subscriber lines;

common call detecting means for detecting call signals originating from the telephone subscriber lines, the common call detecting means being connected to all the telephone subscriber lines when a call signal is not detected by said common call detecting means;

a plurality of first switching means associated with respective individual call detecting means for switching the telephone subscriber lines from said common call detecting means to the corresponding individual call detecting means when said common call detecting means detects a call signal originating from at least one of the telephone subscriber lines, the first switching means including relays for connecting all of said telephone subscriber lines to said common call detecting means when the call signal is not detected by said common call detecting means, and to said corresponding individual call detecting means when the call signal is detected by said common call detecting means;

power supply means for supplying power to said common call detecting means, and for supplying operating power to each of said individual call detecting means only when said common call detecting means detects the call signal originating from at least one of the telephone subscriber lines;

the power supply means including a plurality of individual power supply means for supplying power from said power supply means to respective individual call detecting means only in response to a call detecting signal from said common call detecting means, the individual power supply means including relays for connecting said power supply means to said respective individual call detecting means when the call signal is detected by said common call detecting means; and

means for restoring to initial states those first switching means of said plurality of first switching means and those individual power supply means of said plurality of individual power supply means that are associated with individual call detecting means which do not detect a call signal when the telephone subscriber lines are switched from said common call detecting means to the individual call detecting means.

11. A call detection control apparatus for controlling the detection of call signals originating through telephone subscriber lines connected with individual telephone subscriber terminals, the apparatus comprising:

a plurality of individual call detecting means for detecting respective call signals originating from corresponding telephone subscriber lines;

common call detecting means for detecting call signals originating from the telephone subscriber lines, the common call detecting means being connected to all the telephone subscriber lines when a call signal is not detected by said common call detecting means;

a plurality of first switching means associated with respective individual call detecting means for switching the telephone subscriber lines from said common call detecting means to the corresponding individual call detecting means when said common call detecting means detects a call signal originating from at least one of the telephone subscriber lines;

power supply means for supplying power to said common call detecting means, and for supplying operating power to each of said individual call detecting means only when said common call detecting means detects the call signal originating from at least one of the telephone subscriber lines;

the power supply means including a plurality of individual power supply means for supplying power from said power supply means to respective individual call detecting means in response to a call detecting signal from said common call detecting means;

means for restoring to initial states those first switching means of said plurality of first switching means and those individual power supply means of said plurality of individual power supply means that are associated with individual call detecting means which do not detect a call signal when the telephone subscriber lines are switched from said common call detecting means to the individual call detecting means;

subscriber line test means for selectively performing a line state test of each of the telephone subscriber lines;

second switching means for switching a common test connection path, switched by said first switching means, to said common call detecting means and said subscriber line test means, so that each of the telephone subscriber lines is connected to said common call detecting means through said first and second switching means during a period other than a subscriber line test period; and

means for connecting, during the subscriber line test period, each of the telephone subscriber lines which are not tested to corresponding one of said individual call detecting means through said first switching means, and for connecting one of the telephone subscriber lines which is tested to said subscriber line test means through said first and second switching means.