Wiretap detector and telephone loop monitor

A novel method and improved system for the continuous detection monitoring of authorized/unauthorized connections/disconnections including loop bridging wiretapping equipment capable of monitoring recording voice and/or data communications on the subscriber's local telephone loop. In operation the detector monitor displays electrical changes in impedance condition and characteristics on the subscriber's local telephone loop to detect and monitor signaling, switching equipment and telephone lines connecting/disconnecting anywhere on the loop including the central exchange before, during and after the completion of a telephone call continuously.

BACKGROUND 
1. Field of Invention 
This invention relates to the detection monitoring of 
authorized/unauthorized connections/disconnections including loop bridging 
wiretapping equipment on the subscriber's local telephone loops where 
electrical changes in loop impedance condition and characteristics occur 
because of the connections/disconnections of the briding equipment. 
2. Description of Prior Art 
There are many devices available that have been developed for both legal 
and illegal wiretapping of telephone communications. A very common type of 
wiretapping consists of a bridging device that creates a remote extension 
or drawn loop by connecting an additional telephone line on the 
subscriber's telephone loop and routing it to an observation monitoring 
location. This loop bridging wiretapping technique will cause a change in 
loop impedance condition and characteristics depending on how the tapping 
is completed. 
In the prior art, wiretap detectors exist that utilize microcomputers and 
processors, various meters, signal generators, tone generators, etc., that 
detect wiretapping equipment connected to a telephone line but are either 
simple voltage meters that are ineffective, limited, detachable and 
defeatable, too expensive and/or complicated equipment that is burdensome 
and obtrusive to use on a continuous basis or must be installed on a clean 
line only. 
OBJECTS AND ADVANTAGES 
This invention presents a new device, method and system that displays 
connections and disconnections anywhere on the subscriber's local 
telephone loop including the central exchange of the telephone company 
before, during and after the completion of a call on a continuous basis. 
Each telephone call produces a signature or pattern of connections and 
disconnections. This invention present the first continuous display of 
normal/abnormal telephone loop electrical changes in impedance condition 
and characterization activity resulting from signaling, switching and 
wiretapping monitoring equipment connecting/disconnecting. 
The present invention is easy to use, highly reliable, undetectable, small, 
portable, and discreet which presents a novel method and an improved 
system for detecting monitoring authorized/unauthorized 
connections/disconnections including wiretapping monitoring recording 
equipment which overcome all of the above mentioned disadvantages of the 
previously known devices. 
It is the object of this invention to show how authorized/unauthorized 
connections/disconnections including loop bridging wiretapping equipment 
can be detected and monitored on the subscriber's loop by subscriber's 
telephone terminal(s) equipped with said invention.

REFERENCE NUMERALS IN DRAWINGS 
10 local telephone central exchange 
20 subscriber's local telephone loop 
30 subscriber's residence telephone terminal(s) 
40 capacitive element 
50 detector monitor display assembly 
60 isolation transformer 
70 switching mechanism 
80 modular telephone line 
90 modular telephone line jack 
100 modular telephone interface housing 
DESCRIPTION OF INVENTION 
This invention presents a novel method and improved system that detects and 
monitors authorized/unauthorized connections/disconnections including loop 
bridging wiretapping equipment that causes electrical changes in impedance 
condition and characteristics on the subscriber's local telephone loop to 
detect signaling, switching equipment and telephone lines 
connecting/disconnecting anywhere on the loop including the central 
exchange continuously. 
By continuously monitoring the subscriber's telephone loop impedance 
condition and characteristics, it is possible to detect normal as well as 
abnormal connections and disconnections. Connections and disconnections 
effect changes in impedance characteristics on the subscriber's telephone 
loop and are the indication of wiretapping monitoring equipment 
connecting/ disconnecting. By detecting connections/disconnections it is 
possible to determine authorized/unauthorized connections/disconnections 
including wiretapping equipment on the loop. The proposed method and 
system comprises of monitoring the device's display to establish a normal 
signature or pattern of telephone loop characteristics from an abnormal 
signature or pattern resulting from additional extensions, either at the 
subscriber's residence or remotely connecting/disconnecting on the 
telephone loop. 
OPERATION OF THE PREFERRED EMBODIMENT 
Further objects and advantages of said invention will become apparent from 
a consideration of the drawings and ensuing operation of it. Each of the 
elements included therein can assume several different forms, all of which 
would be well known to those skilled in the art, and it only be required 
that they perform the functions set forth herein after. 
Referring first to the diagram of FIG. 1, it should be noted that FIG. 1 
details a local telephone system. As seen in FIG. 1, a local telephone 
system comprising of the telephone company's central exchange 10 a 
subscriber's local telephone loop 20 and a subscriber's residence 
telephone terminal(s) 30. 
Referring to FIG. 2, there are four presented embodiments of said 
invention, embodiment 2 is the preferred embodiment. As seen in FIG. 2, 
embodiment 1 comprising capacitive element 40 detector monitor display 
assembly 50. 
As seen in FIG. 2, preferred embodiment 2 comprising capacitive element 40 
isolation transformer 60 display assembly 50. 
As seen in FIG. 2, embodiment 3 comprising capacitive element 40 display 
element 50 switching mechanism 70. 
As seen in FIG. 2, embodiment 4 comprising capacitive element 40 isolation 
transformer 60 display assembly 50 switching mechanism 70. 
As seen in preferred embodiment 2, side one of the capacitive element 40 is 
connected to either the Tip or Ring side of the subscriber's telephone 
loop 20. Side two of the capacitive element 40 is connected in series to 
the isolation transformer 60 primary's side one. The isolation transformer 
60 primary's side two is then connected to the alternate side of the 
subscriber's telephone loop 20. The isolation transformer 60 secondary is 
connected to the display assembly 50. 
Once the detector monitor is connected to the loop 20 the device 
continuously detects and monitors electrical changes in impedance 
condition and characteristics on the loop 20 reporting each 
authorized/unauthorized connections/disconnections, as well as tampering 
and changes in loop signature pattern characteristics. 
SUMMARY, RAMIFICATIONS, AND SCOPE 
Each connection and disconnection on the subscriber's local telephone loop 
creates electrical changes in loop impedance condition and 
characteristics. Each telephone call creates a series of normal 
connections and disconnections on the loop, the device's display creates a 
signature or pattern. The system comprises of monitoring the device's 
display to each cell. By detecting electrical changes on the loop it is 
possible to establish a normal pattern of loop activity from an abnormal 
one. 
The preferred method and system comprises of connecting and monitoring the 
display assembly to establish a normal signature or pattern of loop 
impedance conditions and characteristics from an abnormal one resulting 
from additional connections/disconnections and tampering on the loop. 
The device detects and monitors authorized/unauthorized connections and 
disconnections before, during and after the completion of a call on a 
continuous basis. 
It would be obvious to those skilled in the art that numerous 
identifications could be made to the method and system of the present 
invention without departing from the spirit of the invention, which shall 
be limited only by the scope of the claims appended hereto.