WO1998057483A1

WO1998057483A1 - Telephone line monitoring device

Info

Publication number: WO1998057483A1
Application number: PCT/US1998/011459
Authority: WO
Inventors: Kenneth F. Vaughan
Original assignee: Evergreen Communication Technologies, Inc.
Priority date: 1997-06-10
Filing date: 1998-06-03
Publication date: 1998-12-17
Also published as: BR9808861A; UY25038A1; AR005214A1; ZA984964B; JP2001508981A; CN1250569A; AU7813898A; ES2157176A1; PE100299A1; CA2278235A1; ES2157176B1; CO4780075A1

Abstract

A standalone telephone line status monitoring and reporting devi ce (10) for use between a subscriber's premises loop and the local telephone network is disclosed. The device operates on loop current, external AC or DC power from the subscriber's premises, or internal battery (61). The device passively monitors the status of the premises loop until an alarm condition is detected. When premises communications equipment is on-hook or off-hook, the device detects normal Tip-Ring voltage and current conditions. If an open circuit, short circuit, or invalid loop impedance condition is detected, the device indicates a potential fault in the premises wiring. The device then reports the alarm either by visual or audible indications (11), electronically to an external monitoring device, or by auto-dialing one of two preprogrammed telephone numbers. The fault may be reported over wireline telephone line or radio link (21) to the central office or other location. Additionally, when configured for radio link communications with the central office, the device may be remotely reset.

Description

TELEPHONE LINE MONITORING DEVICE

BACKGROUND OF THE INVENTION

Technical Field of the Invention

This invention relates to telecommunication systems and, more particularly, to a telephone line status monitoring and reporting device for use between a subscriber's premises loop and a local telephone network. Description of Related Art

For a business or residential telephone subscriber, service reliability is essential. hen a communications fault occurs, whether on the loop from the Central Office (CO), within the subscriber's premises, or within a telephone or data device, disruption of service can be costly to both the Telephone Operating Company (Telco) and to the end customer. The Telco may be a wireline or wireless operator to include new Personal

Communications Services (PCS) operators and cellular telephone companies (Cellcos).

To restore normal communications following a fault condition within the subscriber's premises or from the premises to the CO, the fault condition must be detected, and then isolated and located. Fault isolation and location is a critical function to determine responsibility for corrective action. For example, if the fault occurs within the subscriber's premises, the wiring and communications equipment may be the responsibility of the occupant or landlord. However, if the fault occurs between the CO and the interface with the customer's premises, the Telco has the responsibility to correct the fault. Several devices currently exist for fault detection, isolation, and localization, however, all of these devices are designed for use with wireline telephone lines, and must be powered from the central office. In parts of many third-world countries, however, wireline telephone lines do not exist. The only way for people in such remote areas to obtain telephone service is through radio telecommunication systems. For these systems, faults within a subscriber's premises are not automatically detected and reported. Therefore, the reliability and availability of such systems is decreased. Additionally, the capability of testing the integrity and the intensity of the radio at mobile handsets across the air interface is built into the signaling protocol definition for PCS radios such as CDMA, GSM and TDMA. However, problems may result in the in- building wiring or the radio transmitting device itself.

Although there are no known prior art teachings of a solution to the aforementioned deficiency and shortcoming such as that disclosed herein, U.S. Patent Numbers 4,390,750 to Bartelink (Bartelink), 4,446,340 to Fryer (Fryer), and 4,817, 137 to Rosenfeld et al. (Rosenfeld) discuss subject matter that bears some relation to matters discussed herein. Bartelink discloses a remote supervisory system for monitoring the status of a subscriber's premises over existing telephone circuits from the central office. Auxiliary equipment at the subscriber's premises is coupled to the subscriber's telephone circuit and includes sensors which monitor the condition of the premises. If an abnormal condition is sensed, the auxiliary equipment notifies the central office which may further notify an action center of the subscriber's identity and nature of the alarm. However, the auxiliary equipment of Bartelink requires contact from the Telco along the wireline from the central office. Thus, Bartelink does not provide a standalone capability to monitor the subscriber's premises and report alarm conditions without a wireline connection to the central office.

Fryer discloses a loopback circuit for testing a telephone line between the central office and a subscriber's equipment. The loopback circuit is located at the subscriber's end of the line and is powered by the normal central office power source. Fryer injects a signal from the central office to actively test the telephone line. Thus, Fryer does not provide a standalone capability, or a passive capability to monitor the subscriber's premises and report alarm conditions without a wireline connection to the central office.

Rosenfeld discloses an apparatus for monitoring the hook status of a remote telephone. Rosenfeld introduces a disturbance voltage signal onto the subscriber loop from the central office, and then monitors variations in impedence in the subscriber loop. Thus, Rosenfeld does not provide a standalone capability, or a passive capability to monitor the subscriber's premises and report alarm conditions without a wireline connection to the central office.

Review of each of the foregoing references reveals no disclosure or suggestion of a system or method such as that described and claimed herein. In order to overcome the disadvantage of existing solutions, it would be advantageous to have a standalone telephone line status monitoring and reporting device for use between a subscriber's premises loop and the local telephone network. The device would passively monitor the status of the premises loop until an alarm condition is detected, and would then report the alarm either by visual or audible indications, electronically to an external monitoring device, or by auto-dialing a telephone number to the central office or other location. The device would report the fault over wireline or radio link to the central office or other location. The present invention provides such a device.

SUMMARY OF THE INVENTION

In one aspect, the present invention is a standalone device for passively monitoring the status of premises telephone wiring, and reporting faults in the wiring either by visual or audible indications, electronically to an external monitoring device, or by auto-dialing a wireline or radio telephone number to the central office or other location designated by the telephone operating company.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be better understood and its numerous objects and advantages will become more apparent to those skilled in the art by reference to the following drawing, in conjunction with the accompanying specification, in which:

FIG. 1 is a simplified block diagram of a first embodiment of the monitoring device of the present invention implemented as a standalone unit;

FIG. 2 is a simplified block diagram of a second embodiment of the monitoring device of the present invention implemented as a monitoring module which is interconnected to a Wireless Subscriber Unit (WSU); and

FIG. 3 is a schematic diagram of the preferred embodiment of a monitoring circuit within the monitoring device of the present invention. DETAILED DESCRIPTION OF EMBODIMENTS

The invention is a telephone line status monitoring and reporting device for use between a subscriber's premises loop and the local telephone network. The device may operate on the loop current, external AC or DC power from the premises, or an internal battery. The device passively monitors the status of the premises loop until an alarm condition is detected. At that time, an alarm is reported either by visual or audible indications, electronically to an external monitoring device, or by auto-dialing a telephone number to the central office or other location.

Under normal operational conditions, when premises communications equipment is on-hook or off-hook, the present invention detects normal Tip-Ring voltage and current conditions. If an open circuit, short circuit, or invalid loop impedance condition is detected, the present invention indicates a potential fault in the premises wiring.

FIG. 1 is a simplified schematic diagram of a first embodiment of the monitoring device of the present invention implemented as a standalone unit. A separate standalone unit 10 is installed on each line in the subscriber's premises. Each standalone unit may independently supply the subscriber, a repair person, or the Telco with an indication that a fault condition has occurred on the line on which the unit is installed. Thus, if the repair person for the premises wiring is independent of the Telco, he will have on- premises feedback that a wiring error has been successfully corrected before leaving the premises.

The standalone unit is installed within the subscriber's premises as close as possible to the Tip (T)-Ring(R) entry point from the telephone network. The standalone unit 10 may be programmed with a plurality of telephone numbers to which specific alarm conditions may be reported. In the preferred embodiment, the standalone unit 10 may be programmed with up to two telephone numbers. When switch SWl is in a closed position at PI, a first telephone number of up to ten digits may be programmed from a standard touch tone (DTMF) premises telephone. A second telephone number of up to ten digits may be programmed when switch SWl is in position P2. In case of a power failure, the standalone unit provides a transparent connection from the subscriber's premises to the telephone network. An indicator 11 such as, for example a LED indicator, indicates the status of the premises telephone wiring and whether the monitor is in a monitor mode or a program mode. The monitor is automatically in the monitor mode unless a reporting telephone number is being programmed. FIG. 2 is a simplified block diagram of a second embodiment of the monitoring device of the present invention implemented as a monitoring module 20 which is interconnected to a Wireless Subscriber Unit (WSU) 21. The WSU 21 provides a radio communications interconnection from the subscriber's premises to a telephone network. The monitoring module 20 may be internal to the WSU 21, or may be externally connected to the WSU 21.

The WSU 21 may provide an interface for a single wireless transmit and receive path (TRX) for a specified radio technology such as from Ericsson (DECT and PCS 1900), Nortel (CDMA, GSM and TDMA), National Panasonic (PACs and PHS), Mitsubishi (PHS), Qualcom (CDMA), Motorola (CDMA and PACs), Nokia (PCS 1900 and PACs), and Lucent (CDMA and PACs). In addition, the WSU 21 may provide a data adapter for personal computer (PC) and facsimile (FAX) communication. In such a situation, the WSU 21 may be connected directly to the PC or FAX device, without the use of premises telecommunications wiring.

In the configuration shown in FIG. 2, the monitoring module 20 is DC powered from the WSU 21, and is connected to the WSU by a six-pin connector or cable. The pins are labeled T (in), R (in), V+, V-, PS1, and PS2. The monitoring module 20 communicates the status of the premises telephone wiring to the WSU 21 via logic pins PS1 and PS2. Additionally, the monitoring module 20 may be reset remotely through the logic pins PS1 and PS2. The premises telephone wiring is connected to the T (out) and R (out) pins off the monitoring module, and the DC power source is connected to pins V+ and V-.

Either embodiment of the monitoring and reporting device of the present invention may be integrated with a premises security alarm system. A fault condition in the premises wiring is then reported by the security alarm system to a central monitoring center. FIG. 3 is a schematic diagram of the preferred embodiment of a monitoring circuit within the monitoring device of the present invention. The monitoring circuit 31 includes a LM 741 Linear Operational Amplifier 33 which operates as a comparator device, a phone (in) 35 having a T(in) pin 37 and a R(in) pin 39, and two phone (out) connections 41 and 43. Phone (out) connection (1) 41 includes a T,(out) pin 45 and a R_j(out) pin 47, and phone (out) connection (2) 43 includes a T₂(out) pin 49 and a R₂(out) pin 51. The circuit also includes a 2N3904 transistor 53 which functions as an emitter- follower circuit, a first LED (LED 1) 55, a second LED (LED 2) 57, a test point (TP) 59, and a power source 61. The LM 741 comparator 33 is an off-the-shelf linear operational amplifier and is used in the inverting mode. The phone (in) connection 35 is an interface between the monitoring circuit 31 and the Telco via the Tip-Ring connections of pins T(in) 37 and R(in) 39. The TP 59 is a test point for on-site troubleshooting or installation testing of the monitoring circuit 31. Phone (out) connection (1) 41 provides a Tip-Ring interface to the premises wiring pins T, (out) 45 and R,(out) 47. Phone (out) connection (2) 43 provides an auxiliary output through the pins T₂(out) 49 and R₂(out) 51. The auxiliary output, phone (out) connection (2) 43, may be utilized for example, when the WSU 21 (FIG. 2) is connected across a Tip-Ring connection, and the integrity of the wiring from the WSU 21 to the Tip-Ring connection needs to be specifically monitored. Additionally, an auxiliary output may be implemented to interface the monitoring and reporting device with a premises security alarm system.

If the Telco Tip-Ring interface at T(in) 37 and R(in) 39 is either open circuited or short circuited, the LM 741 comparator 33 applies a positive bias to the 2N3904 transistor 53. This opens the circuit to LED 1 and LED 2, and to phone (out) connection (1) 41 and phone (out) connection (2) 43. The status at the interface of the premises is reflected on LED 1 and LED 2, which are status indicators. In addition, if an abnormal impedance condition occurs in the premises wiring, such as a short-circuit across out (1), LED 1 and LED 2 also indicate the change in status. Although LED 1 and LED 2 are used in FIG. 3 as indicators, other methods may be employed to report the status of the system. For example, an emitter-follower circuit such as transistor 53 may be utilized to drive digital NAND gates providing a TTL logic output to indicate circuit status and also provide an optional direct digital interface into the WSU 21 for wiring status reporting. Additionally, sound emitters may be used instead of or in addition to LED indicators to provide an audible indication of an abnormal status.

The power source 61 normally provides 12 volt DC power. The DC power could optionally be provided by the WSU 21.

It is thus believed that the operation and construction of the present invention will be apparent from the foregoing description. While the method, apparatus and system shown and described has been characterized as being preferred, it will be readily apparent that various changes and modifications could be made therein without departing from the spirit and scope of the invention as defined in the following claims.

Claims

WHAT IS CLAIMED IS:

1. A standalone device for passively monitoring premises telephone wiring, and reporting faults in the wiring, said device comprising: a sensor component for measuring a plurality of conditions in said premises telephone wiring, said sensor component operating without a connection to a telephone company central office; a monitoring circuit connected to said sensor component that utilizes measurements from said sensor component to determine a plurality of alarm conditions; a reporting component connected to said monitoring circuit for reporting said plurality of alarm conditions; and a power supply for powering said sensor component, said monitoring circuit, and said reporting component.

2. The monitoring and reporting device of claim 1 wherein said sensor component includes means for measuring Tip-Ring voltage and current.

3. The monitoring^' and reporting device of claim 2 wherein said sensor component includes means for measuring premises loop impedence.

4. The monitoring and reporting device of claim 1 wherein said plurality of alarm conditions includes: an open circuit in said premises wiring; a short circuit in said premises wiring; and invalid loop impedence.

5. The monitoring and reporting device of claim 1 wherein said reporting component includes means for reporting alarm conditions by a visual indication.

6. The monitoring and reporting device of claim 1 wherein said reporting component includes means for reporting alarm conditions by an audible indication.

7. The monitoring and reporting device of claim 1 wherein said reporting component includes means for reporting alarm conditions electronically to an external monitoring system.

8. The monitoring and reporting device of claim 7 wherein said means for reporting alarm conditions electronically to an external monitoring system includes means for integrating said monitoring and reporting device with a premises security alarm system.

9. The monitoring and reporting device of claim 8 wherein said means for reporting alarm conditions electronically to an external monitoring system includes a plurality of digital NAND gates driven by an emitter-follower circuit, said NAND gates producing a TTL logic output to indicate premises wiring status.

10. The monitoring and reporting device of claim 7 wherein said means for reporting alarm conditions electronically to an external monitoring system includes a wireless subscriber unit for communicating by radio to a telephone network.

11. The monitoring and reporting device of claim 1 wherein said reporting component includes means for reporting alarm conditions by auto-dialing a telephone number to a telephone company central office.

12. The monitoring and reporting device of claim 1 wherein said reporting component includes means for reporting alarm conditions by auto-dialing a telephone number to a location designated by a telephone company.

13. The monitoring and reporting device of claim 1 wherein said power supply is an internal battery.

14. The monitoring and reporting device of claim 1 wherein said power supply is DC power from the premises.

15. The monitoring and reporting device of claim 1 wherein said power supply is external AC power from the premises.

16. A standalone device for passively monitoring premises telephone wiring, and reporting faults in the wiring, said device comprising: a sensor component for measuring Tip-Ring voltage, Tip-Ring current, and premises loop impedence in said premises telephone wiring; a monitoring circuit connected to said sensor component that utilizes measurements from said sensor component to determine an open circuit, a short circuit, and invalid loop impedence; a reporting component connected to said monitoring circuit for reporting said alarm conditions electronically to an external monitoring system; and a power supply for powering said sensor component, said processor, and said reporting component, said power supply comprising DC power from the premises.