SERVICE OBSERVING SYSTEM

• US 3,704,348 A
• Filed: 11/06/1970
• Issued: 11/28/1972
• Est. Priority Date: 11/06/1970
• Status: Expired due to Term

• Current Assignee: Alexander Charles Mcintosh, Maurice Irvin Smith
• Original Assignee: Alexander Charles Mcintosh, Maurice Irvin Smith
• Inventors: Smith, Maurice Irvin, McIntosh, Alexander Charles
• Primary Examiner(s): Claffy, Kathleen H.
• Assistant Examiner(s): Olms, Douglas W.
• Application Number:
  US05/087,464
• Time in Patent Office: 753 Days
• Field of Search: 179/175.2C,1MN,2DP
• US Class Current: 379/35
• CPC Class Codes: H04M 3/22 Arrangements for supervision, monitoring or testing

Abstract

To allow an observer at any remote subset on a telephone network to observe the quality of service provided to customers in a local area thereof, a service observing unit is connected to each line and trunk to be observed at the local area and to an incoming trunk from an adjacent central office. When the remote observer dials a connector number at the central office assigned to the service observing unit, an observer line connector connects the unit to the remote observer and transmits an identity tone thereto. The remote observer must then dial a security access code comprising a plurality of multi-frequency signals with established inter-signal spacing in a given sequence within a predetermined time period, or a timing and disconnect circuit within the unit releases the connection established by the observer line connector. If a correct code has been dialed, an inhibit signal is provided to the timing and disconnect circuit and an idle tone is transmitted to the remote observer. A plurality of selectors and connectors, one for each trunk or line to be observed, are then enabled by a reset signal. The first of these observed trunks or lines to have a calling signal thereon is detected by its corresponding selector which then supplies an inhibit signal to the remaining selectors and connects its line or trunk through its connector to an amplifier, and a hybrid bridging network to the remote observer. To select another line or trunk, the observer dials the last multi-frequency signal of the security access code so that a reset signal is supplied to all the selectors. To disconnect, the remote observer may place his subset on-hook or dial a disconnect multi-frequency signal. A solid-state embodiment of the unit is also discussed, as is a modification allowing selective access by the remote observer to a plurality of trunk or line groups.

Claims

1. A service observing unit for coupling an observer at a remote subset of a voice telephone network to a plurality of trunks and lines located at one station of the network, the telephone network including an incoming trunk connected to the station, and further including means providing multi-frequency signals on the incoming trunk in response to digits dialed at the remote subset, as well as a ringing signal from that subset, comprising:

a. an observer line connector including means responsive to said ringing signal for simultaneously connecting said service observing unit to the incoming trunk and providing a first control signal, and responsive to a second control signal for disconnecting said service observing unit from the incoming trunk, b. a timing and disconnect means including means providing said second control signal at a predetermined time after the production of said first control signal, c. tone receiving and detecting means coupled to said incoming trunk for providing a first output signal in response to the presence of a first multi-frequency signal thereon, and for providing a second output signal in response to a presence to a second multi-frequency signal thereon, and d. security access means including means providing an inhibit signal if, and only if, said first output signal is provided before said second output signal, and means coupling said inhibit signal to said timing and disconnect means to inhibit the production of said second signal thereby.

2. a selector means having said one of said telephone circuits coupled thereto and being actuated in response to the concurrence of said reset signal and said control signal to connect said one of said telephone circuits to the incoming trunk.

3. The service observing unit as recited in claim 1, wherein said timing and disconnect means comprises:

a. a first programmable unijunction transistor having gate, anode and cathode terminals, b. a potential source having a pair of terminals, c. means connecting said cathode terminal to one of said terminals of said potential source, d. means developing from said potential source a first reference potential, e. means coupling said first reference potential to said gate terminal to establish a given forward breakdown voltage at said anode terminal thereof, f. means responsive to said first control signal from said observer line connector for developing from said potential source a first potential whose initial value is less than said anode forward breakdown voltage and whose magnitude thereafter increases at a predetermined rate, and g. means coupling said first potential to said anode terminal, whereby said first programmable unijunction transistor is placed in a conducting condition to produce said second control signal when said first potential exceeds the said forward breakdown voltage,

4. The service observing unit as recited in claim 3, wherein said security access means further includes means responsive to said inhibit signal for increasing said first reference potential so that said first programmable unijunction transistor cannot be placed into a conducting condition.

5. A service observing unit as recited in claim 3, wherein said inhibit signal providing means of said security access means comprises:

a. a second programmable unijunction transistor having second gate, anode and cathode terminals, b. means coupling said second cathode terminal to one of said terminals of said potential source, c. means developing a second reference potential from said potential source, d. means connecting said second reference potential to said second gate terminal to establish a given forward breakdown voltage at said second anode terminal thereof, e. means connected to said potential source for developing in response to said first output signal a second potential whose initial value is less than said second anode forward breakdown voltage but greater than that at said first terminal of said potential source, f. means developing a third potential from said potential source in response to said second output signal, g. means summing said second and said third potentials to produce a summed potential, h. means coupling said summed potential to said second anode terminal, whereby, said second programmable unijunction transistor is placed in a conducting condition to produce said inhibit signal.

6. The service observing unit as recited in claim 5, wherein said inhibit signal providing means further includes means decreasing the magnitude of said second potential at a predetermined rate.

7. The service observing unit as recited in claim 1, further comprising:

a. a plurality of connector circuits, each of said connector circuits being connected across one trunk or line to be observed and including a signaling means for providing a third control signal upon the initiation of any call on said trunk or line, b. a plurality of selector circuits, each of said selector circuits being coupled to one trunk or line through the associated one of said connector circuits and including switching means responsive to said third signal therefrom for connecting said trunk or line to an output thereof, c. amplifier means coupling a plurality of said outputs from said selector circuits to said means within said observer line connector which bridges a connection to the telephone network incoming trunk, and d. means responsive to the operation of any of said switching means for inhibiting the operation of said switching means in the remaining onEs of said selector circuits.

8. The service observing unit as recited in claim 7, wherein said security access means further includes means producing a reset signal whenever said inhibit signal is provided thereby, and each of said selector circuits further includes means enabling said switching means therein for operation only during the production of said reset signal.

9. The service observing unit as recited in claim 8, wherein said security access means further includes means responsive to said second output signal from said tone receiving and detecting means for temporarily stopping the production of said reset signal.

11. The service observing unit as recited in claim 7, wherein said tone receiving and detecting means includes means for providing a fourth output signal in response to the presence of a fourth multi-frequency signal on said incoming trunk, and means for providing a fifth output signal in response to the presence of a fifth multi-frequency signal on said incoming trunk, and further comprising:

a. means having first and second sets of input terminals and one set of output terminals, a first group of said trunks and lines being coupled to said first set of input terminals and a second group of said trunks and lines being connected to said second set of input terminals, said means being operative to normally connect said first set of input terminals to said set of output terminals and to connect said second set of input terminals to said set of output terminals whenever a switching signal is applied thereto, b. means connecting said set of output terminals to said plurality of connector circuits, and c. means actuated in response to said fourth output signal for producing said switching signal, and de-actuated in response to said fifth output signal.

12. An apparatus for connecting an observer at a remote subset of a telephone network to one station of the network, said station including a group of telephone circuits and being connected to an incoming trunk of the network, said telephone network including means for connecting the remote subset to the station through said incoming trunk, comprising:

a. a first connector means responsive to a first signal from the observer appearing on the incoming trunk for connecting said apparatus to the incoming trunk, b. disconnect means for automatically disabling said connector means to break said incoming trunk connection at a predetermined time after the reception of said first signal thereby, and c. security access means for inhibiting said disabling operation of said disconnect means, said security access means being responsive to a second signal from the observer appearing on the incoming trunk, said second signal comprising a plurality of distinct multi-frequency signals, said security access means further including a receiving means coupled to said incoming trunk and detecting said plurality of distinct multi-frequency signals to provide a distinct output signal for each signal so detected, means producing a timing signal for a predetermined time period after the production of a particular one of said output signals by said receiving means, and gating means providing an inhibit signal to said disconnect means for disabling its operation upon the concurrence of a second, distinct one of said output signals and said timing signal.

13. An apparatus as recited in claim 12, a. wherein said security access means further includes means producing a reset signal upon the inhibiting operation thereof, b. further comprising,

14. An apparatus as recited in claim 12, wherein said security access means includes means responsive to a third, distinct one of said output signals from said receiving means for stopping the production of said inhibit signal by said gating means so that said disconnect means disabled said first connector means.

15. An apparatus for connecting an observer at a remote subset of a telephone network to a plurality of telephone circuits located at one station of the network, said station being connected to an incoming trunk of the network and the network including means for connecting the remote subset to the station through said incoming trunk, comprising:

a. a first connector means responsive to a first signal from the observer appearing on the incoming trunk for connecting said apparatus to the incoming trunk, b. disconnect means for automatically disabling said connector means to break said incoming trunk connection at a predetermined time after the reception of said first signal thereby, c. security access means for inhibiting said disabling operation of said disconnect means, said security access means being responsive to a second signal from the observer appearing on the incoming trunk and including means producing a reset signal upon the inhibiting operation thereof, d. a plurality of second connector means, each of said second connector means being coupled to one of said plurality of telephone circuits and including means operative to produce a control signal upon the initiation of a call on its telephone circuits, and e. a plurality of selector means, each of said selector means having one of said telephone circuits coupled thereto and including means actuated in response to concurrence of said reset signal and a control signal from that one of said plurality of said second connector means which is also coupled to said telephone circuit to connect said telephone circuit to said incoming trunk and to disable the remainder of said plurality of selector means.

16. An apparatus as recited in claim 15, wherein said security access means includes means temporarily stopping the production of said reset signal during the reception of a third signal on said incoming trunk, so that said one of said selector means that has been actuated is de-actuated to break the connection therethrough of its telephone circuit to said incoming trunk and to enable all of said selector means for further operation.