Abstract: In some examples, a device includes a power structure and a sensing structure that is electrically isolated from the power structure. The device also includes processing circuitry configured to determine whether the sensing structure includes a prognostic health indicator, wherein the prognostic health indicator is indicative of a health of the power structure.

Abstract: A method and a system for measuring market data in a mobile communications system. The method and system may be used to obtain data such as growth, churn rate, and other measurable metrics of mobile communications device subscribers. The method includes selecting a sample of contact numbers, using one or more contacting or querying methodologies to assess the state of the contact numbers, and analyzing the results to determine the market data.

Abstract: In an illustrative embodiment, a data interface circuit is provided. The data interface circuit comprises data sources, input blocks, a space switch, output blocks and a multi-core processor. The data interface circuit allows data provided in different voltage ranges and sampling frequencies to be transmitted to the appropriate core in the multi-core processor via the switch. Data conversion elements in the input blocks convert data from the data sources and having varying voltage ranges and sampling frequencies into data having a voltage range and sampling frequency suitable for the space switch. Analogously, data conversion elements in the output blocks convert data from the space switch into data having a voltage range and sampling frequency suitable for the corresponding core in the multi-core processor. In one embodiment, level shifters and FIFO buffers are used in the input blocks and output blocks.

Abstract: Disclosed herein is a method and apparatus for detecting surveillance devices on a telephone line and deployment of countermeasures therefor. The apparatus comprises a line monitoring circuit for evaluating whether the phone is off hook or ringing. A test generation circuit produces a test signal to be injected into a line and issues test commands. A signal response analysis circuit compares a test signal response to a baseline signal response and reports an anomaly when the difference between a test signal response and a baseline signal response exceeds a threshold. Additionally, an anomaly may be reported when an unusual signal is detected, such as a clock. A detection management circuit issues countermeasures to the anomaly based on programmed responses.

Abstract: The present invention provides for a system and method for blocking leakage signals and uncoupling connections in a communication system. A leakage signal (LS) blocking splitter employs a high-pass filter which effectively blocks the lower frequency leakage signal. The high-pass filter (an LS filter) has a cut-off frequency selected to fall between the upper range of the leakage signal (which is approximately 4 KHz in the preferred embodiment) and the low-end frequency of a data signal. A detect and terminate function detects service on the communication connection to which each one of the leakage signal (LS) filters are coupled to. The detect and terminate function detects service on the communication connection to ensure that each LS blocking splitter is coupled to an in-service communication connection.

Abstract: The present invention discloses a method for obtaining key management server information, and an intercepting method, system and device, including: in the process of a user equipment registering an IP multimedia subsystem (IMS), storing the KMS information corresponding to the user equipment in a preset IMS core network network element; and when a lawful intercepting device monitors a session initiated by the user equipment, intercepting a session request signaling sent by the user equipment, and obtaining an identification information of the user equipment from the session request signaling, and searching the KMS information corresponding to the user equipment from the preset IMS core network network element according to the identification information of the user equipment. The technical solution of the present invention makes the requirement of lawful intercepting be met without depending on security of the signaling plane when a plurality of KMSs are deployed in the IP multimedia subsystem.

Abstract: A system and method automatically learns mailbox configuration conventions. The validator module determines a valid set of configuration parameters used for accessing an electronic mailbox of a user within a mail domain after receiving configuration information from the user that is limited in the configuration parameters required for accessing the electronic mailbox. A learner module accepts from the validator module a set of configuration parameters determined to be valid and generates configuration conventions for a mail domain. A database store is the generated configuration conventions. The validator and learner modules can be operative as part of a web server.

Abstract: A method of analyzing the performance of a modem connection. The method includes connecting a line interface to a communication link carrying signals of a modem connection, between a pair of end modems, collecting signals passing on the communication link, between the end modems, through the line interface, determining quality or transmission characteristics regarding the modem connection, responsive to signals collected through the line interface, and displaying information on the determined characteristics.

Abstract: A method and apparatus for automating test procedures to determine if non-emergency signaling message processing errors impact emergency calls, e.g., E911 calls, are disclosed. In one embodiment, the present method alerts network engineers so that crankback procedures to alternative routes can be instituted when these E911 call impacting error conditions are detected in a network.

Abstract: Disclosed herein is a method and apparatus for detecting surveillance devices on a telephone line and deployment of countermeasures therefor. The apparatus comprises a line monitoring circuit for evaluating whether the phone is off hook or ringing. A test generation circuit produces a test signal to be injected into a line and issues test commands. A signal response analysis circuit compares a test signal response to a baseline signal response and reports an anomaly when the difference between a test signal response and a baseline signal response exceeds a threshold. Additionally, an anomaly may be reported when an unusual signal is detected, such as a clock. A detection management circuit issues countermeasures to the anomaly based on programmed responses.

Abstract: A system and method automatically learns mailbox configuration conventions. The validator module determines a valid set of configuration parameters used for accessing an electronic mailbox of a user within a mail domain after receiving configuration information from the user that is limited in the configuration parameters required for accessing the electronic mailbox. A learner module accepts from the validator module a set of configuration parameters determined to be valid and generates configuration conventions for a mail domain. A database store is the generated configuration conventions. The validator and learner modules can be operative as part of a web server.

Abstract: Methods and apparatus are provided for preventing a third party from listening to a conversation between at least two participants on a telephone. The telephone generates an audio stimulus signal that is presented through a secondary speaker. The audio stimulus signal may be, for example, pseudorandom noise or a cancellation signal. According to one aspect of the invention, the telephone ensures that the audio stimulus signal does not significantly impair the conversation for the at least two participants. To prevent the third party from listening to the local portion of the conversation, the audio stimulus signal is subtracted from the received signal prior to presenting the received signal to the user. To prevent the third party from listening to the remote portion of the conversation, the audio stimulus signal is subtracted from the received signal.

Abstract: A method and apparatus for automating test procedures to determine if non-emergency signaling message processing errors impact emergency calls, e.g., E911 calls, are disclosed. In one embodiment, the present method alerts network engineers so that crankback procedures to alternative routes can be instituted when these E911 call impacting error conditions are detected in a network.

Abstract: The invention relates to a method for carrying out monitoring in packet-oriented telecommunication networks and data networks. The method makes it possible to reduce the processor performance required to carry out legal monitoring of telecommunication subscribers in switching nodes of packet-oriented telecommunication and data networks. To reduce the high number of comparably short data packets which must be respectively compared with the full list of subscriber connections which are to be monitored throughout the network and the computer power resulting therefrom required to carry out the tasks in each network node, the method is based on a reduced individual node list which is automatically generated and maintained and the number of individual verifications is kept to a minimum within a network node.

Abstract: The present invention provides for a system and method for blocking leakage signals and uncoupling connections in a communication system. A leakage signal (LS) blocking splitter employs a high-pass filter which effectively blocks the lower frequency leakage signal. The high-pass filter (an LS filter) has a cut-off frequency selected to fall between the upper range of the leakage signal (which is approximately 4 KHz in the preferred embodiment) and the low-end frequency of a data signal. A detect and terminate function detects service on the communication connection to which each one of the leakage signal (LS) filters are coupled to. The detect and terminate function detects service on the communication connection to ensure that each LS blocking splitter is coupled to an in-service communication connection.

Abstract: The present disclosure discloses a method and apparatus for detecting and preventing telephone call fraud. The call fraud detector apparatus is connected to the telephone line, and includes a telephone line interface with switch hook. A parallel set detector indicates to the microcontroller that another device has gone off hook on the telephone line. The microcontroller causes the telephone line interface switch hook to also go off hook in parallel, thereby preventing pulse dialing by the other device. The device may also include a DTMF tone detector and generator to prevent DTMF dialing on the telephone line. The call fraud detector can provide a visual, audible, and/or tactile indication when unauthorized use of the telephone line occurs, and can be enabled or disabled by an external device. The call fraud detector can log the time and date of each unauthorized call placed on a line, and can also notify the telephone service provider when an unauthorized call is attempted.

Abstract: A method of monitoring a call with a mobile terminal (MT) in an Internet Protocol (IP)-based network having a Gatekeeper that controls the network, a plurality of access routers that provide access to the network, and a Monitoring Station having monitoring facilities and a database of MTs to be monitored. When the MT sends an Admission Request message to the Gatekeeper, the Gatekeeper sends a query to the Monitoring Station asking whether the MT is to be monitored. The Monitoring Station sends a reply to the Gatekeeper indicating that the MT is to be monitored and providing an IP address where monitored packets are to be sent. The Gatekeeper then sends a monitoring request message to the access router associated with the MT. The request identifies the MT to be monitored, instructs the access router to monitor the MT, and provides a unique call identification (Call ID) and the IP address where monitored packets are to be sent.

Abstract: Authorized intercepts of communications in a satellite communications system (10) are performed, according to which a law enforcement agency (LEA) can request the intercept of communications to and/or from subscriber units (SUs). In one embodiment, an LEA intercept request causes an intercept order for a particular target SU (420, FIG. 6) to be transmitted to one or more satellites (411-413, FIG. 6), where the intercept order is stored in an intercept table (410). Any communications traffic involving the target SU results in an intercept by a satellite, which routes a copy of the intercepted communications to the requesting LEA, either directly or via an associated intercept facility (426, FIG. 8).

Abstract: A method and a system for monitoring telephone calls are described. A useful signal (which represents the call information of a telephone call) and a data set (which contains at least one digital subscriber tag) are supplied to a recording center (20). The data set is supplied to a relaying device (28), in which it is compared with stored comparison data sets. If the subscriber tag matches a corresponding comparison tag of a selected comparison data set, a communications link is produced to a monitoring device (36).

Abstract: The eavesdropping prevention system and method of the present invention provides a mask signal generator which generates a mask signal superimposed over a leakage signal. The mask signal prevents meaningful detection and amplification of the leakage signal. The amplitude of the mask signal is low enough so as not to interfere with the transmission of analog POTS signals over the communication line on which the mask signal is superimposed. In the preferred embodiment, the amplitude of the mask signal exceeds the amplitude of any anticipated leakage signals which may be manifested on the communication line. Alternative embodiments of a mask signal are described.

Abstract: A system for controlling and monitoring the recording of telephone calls in institutions such as jails and correctional facilities, and for obtaining consent to such recording and monitoring. Calls are recorded automatically in response to the occurrence of specific triggering events, as pre-defined under software control by a system administrator. Triggering events may include, for example, use of a specific line, attempts to use particular features (such as three-way calling), attempts to dial particular telephone numbers, or use by a particular person. Consent to recording or monitoring is obtained from either the calling or called party, or both, in a language selected for such party. Evidence of which prompts were played to request consent, the language of such prompts, and whether consent was given is stored in a computer readable record. Recorded calls are digitized and stored in standard MS-DOS files on either a local computer system or a remote computer across a network.

Abstract: The call number of a subscriber to be monitored is flagged in the service control point SCP with an indicator of one or more subscribers that are authorized to eavesdrop. When a communications link is set up, an identifier for the monitoring measure is transmitted to the exchange SSP, and a conference loop between the subscriber to be monitored, a calling or called second communications subscriber, and a third subscriber which is authorized to monitor is set up as soon as the identifier is known at the SSP.

Abstract: A lawfully authorized electronic surveillance operation requires reporting of detailed call data for a variety of calls associated with the subject of the surveillance. For at least some specified calls to or from the subject, the invention provides profile data in a switching office serving the subject that causes the office to generate accounting messages for each call, essentially in the same manner as for billing, regardless of whether the calls are billable. Accounting records formed from the messages are uploaded to a server system, for processing and formatting as necessary for delivery to the law enforcement agency. The surveillance could entirely rely on these accounting records for the data reporting. In the preferred embodiments, however, the surveillance also involves monitoring of common channel signaling messages to accumulate call detail records for surveillance purposes, with respect to many calls associated with the subject.

Abstract: A method and apparatus in a communications system for providing call interception. A call is received at a switch in the communications system. Responsive to the call involving a service using identification numbers unknown to the communications system, a remote database associated with the service is queried, wherein the remote database contains a plurality of identification numbers. A result is received from the remote database in response to querying the remote database. A call interception service is initiated based on the result.

Abstract: A technique for monitoring the calls placed to the telephone number associated with the party under surveillance. When a call to the telephone number associated with party under surveillance is placed, the call is routed via an assigned meet-me bridge, and a third party is provided with the unique telephone number of the meet-me bridge via a pager. When the third party places a call to the assigned meet-me bridge, the incoming call to the party under surveillance and the call by the third party are bridged. Thereon, the third party is placed on mute and the third party may silently listen to the conversation between the caller and the called party. When a call (i.e., a page) to a telephone number associated with a pager of the party under surveillance is received, a third party is alerted.

Abstract: A method and apparatus for monitoring voice and data telephone calls by a law enforcement agency, wherein separate monitoring connections for each party to the call are established. Upon determining that a particular call is to be monitored, the group switch attempts to establish a plurality of separate connections between each multiple point (MUP) on the group switch that receives voice or data signals from one of the parties to the call and one or more monitoring centers. If the connection associated with the primary party to be monitored fails, the group switch reroutes signals received from the primary party to a successful connection of the plurality of attempted connections.

Abstract: A method and system for automatically detecting that a telephone port is being used and securing the telephone line associating with the telephone port, is presented. In one embodiment, a method and system is described for automatically securing a telephone line in a telephone system having more than one telephone lines. Usage of a device connected to the telephone line is first detected. Telephones in the system are notified via a data packet to secure the telephone line. In response to the data packet, the telephones prevent a user from accessing the telephone line.

Abstract: A monitoring device monitors signaling information on data links of a telecommunication network. The monitoring device also monitors user traffic on voice links of the telecommunication network. From the signaling information and user traffic a measure of user perception quality is derived.

Abstract: Telephone network surveillance is provided for targeting subscriber terminals that receive service through an office lacking a switch with surveillance capability. A foreign exchange line is relied upon to connect the target's line to an office having that capability. Advanced Intelligent Network (AIN) functionality controls routing and billing of incoming and outgoing calls, so that the telephone network operations appear completely normal during the surveillance. In the office normally serving the target's line, a terminating attempt trigger causes that office to obtain instructions from a service control point (SCP), to route the call to the foreign exchange line terminated in the office with the surveillance capability. The instructions also prevent billing of the redirection through the surveillance office to either the called party or the calling party.

Abstract: Following the Communications Assistance for Law Enforcement Act (CALEA), the FBI developed a standard set of communication services and interfaces for lawfully authorized electronic surveillance. For telephone communications, the current industry implementation of compliance with this standard involves deploying certain interface equipment in end office switches of the telephone network. However, the requisite surveillance functionality often resides in a certain limited number of offices. Where the target under surveillance receives service out of an office lacking the surveillance capability, the network routes the call through an office having the requisite capability. For this purpose, the invention relies on intelligent network processing, particularly variations on such processing normally used to implement local number portability.

Abstract: With a personal call manager, when a caller calls a primary telephone number for the owner of the personal call manager, the personal call manager selectively routes the incoming call to any combination of local extensions on the owner's premises, and to remote extensions such as a telephone instrument on another premises, a pager, a cellular telephone, a central office voice mail box, and a cellular telephone voice mail box. The personal call manager retains control over an incoming call throughout the duration of the call. Consequently, the owner can route the incoming call to multiple locations, or transfer the call to a telephone answering service at any time after taking the incoming call. The personal call manager permits a user to monitor, either locally or remotely, a message being left with a telephone answering service, e.g.

Abstract: A telephone privacy and alerting device for connection between a common telephone line and a telephone device. The privacy and alerting device includes a privacy circuit to prevent the telephone device from accessing the telephone line when another telephone device is already off-hook, and an alerting circuit to indicate an alarm when the telephone device is off-hook and a further telephone device is also off-hook. The privacy circuit includes a voice connecting circuit for connection between the telephone line and the telephone device, a self-latching switch means connected to the voice connecting circuit having an on and off state, and voltage breakdown means for turning the self-latching switch means on when a closed circuit is provided through the telephone device and the potential across said telephone line is above a first predetermined threshold, thereby allowing the voice connecting circuit to establish a current path between the telephone line and the telephone device.

Abstract: A telephone wiretapping system having a call-forward event and reporting processor for producing a call-forward event control signal when a call from a calling party to a predetermined telephone line is to be call-forwarded to a different telephone line. A switch is responsive to the control signal produced by the call forward event and reporting system for switching the recording device from the target telephone line to the call-forward event and reporting processor when the control signal indicates a call-forwarding event. With such an arrangement, the recording device will recorded calling event signals to, or from, the target telephone line even though the calling event signals are occurring at the call-forwarded telephone line. The call-forward event and reporting processor produces signalling information taking place between the telephone line of the calling party and the telephone line of the different, call-forwarded telephone line.

Abstract: A method for use in an electronic switching system having more than one operator position system connected thereto, is used for wiretapping in order to determine a time length of a telephone call between a caller and a receiver. The method comprises the steps of: (a) measuring an elapsed time from the instant the caller is connected to the receiver; (b) checking if the elapsed time reaches a preset time; (c) wiretapping when the elapsed time reaches the preset time; (d) resetting the elapsed time and going back to step (a) if the caller is determined to be still on the line by the wiretapping; and (e) releasing the connection between the caller and the receiver if the caller is determined not to be on the line any longer by the wiretapping.

Abstract: The invention relates to a communication system comprising a station (2) for charge metering of a connection point. This station comprises a monitoring circuit (7) for detecting a request for a connection set-up from the connection point (3), either for establishing the absence of a message after a given period of time, or for evaluating the contents of a message that has arrived from the connection point (3) after the request for a connection set-up has arrived, and for rejecting the request for a connection set-up if invalid parameters of the connection point (3) are established.

Abstract: A digital cellular telecommunication network (30) uses transcoders (50) which vocode voice using a maximal lossy compression algorithm which conserves spectrum usage. A call path for an intercepted call is looped from an outer space satellite (32) network into an intercepting terrestrial gateway (34). Compressed call data for each of two half-calls in this call path bypass normal transcoders (50) through the use of rate adapters (80) which translate between data communication protocols that operate at different data rates without voice coding and decoding. After rate adaptation, the compressed call data are combined in a conference bridge (90), and routed to a monitoring center (60). A subscriber unit (36), a second device (48), and the monitoring center (60) all receive call data which has experienced only one compression/decompression cycle.

Abstract: An apparatus comprising a pair of sensors for monitoring the status of a telephone line and a local station which detects unauthorized use and causes actuation of a disruption signal to make the telephone line unusable.

Abstract: Remote telephone coder 10R and local telephone coder 10L provide coding and decoding for voice communication between remote telephone set 11R and local telephone set 11L through telephone line 12. An eavesdropper listening in on a listening device such as remote extension telephone 14R or local extension telephone 14L hears normal "in-the-clear" conversation (uncoded transmissions) when both of the telephone coders are in the normal mode. However, when both of telephone coders 10R and 10L are in the code mode, the extension eavesdropper using an extension telephone or other unauthorized listening device 14 (shown in phantom) hears only coded transmissions. Further, a remote eavesdropper on remote extension telephone set (main portion 17M with hand portion 17H) employing remote extension coder 16R is also excluded from the coded transmissions between remote telephone coder 10R and local telephone coder 10L.

Abstract: A telephone alerting device for connection to a telephone line and a telephone. When the telephone is off-hook, the device will generate a visual and an audio alarm if an additional telephone connected to the same line also goes off-hook, thereby providing an eavesdropping alarm. The audio alarm is a periodic signal of short duration heard in the ear-pieces of all off-hook telephones connected to the telephone line. The device includes a voice path having a resistor placed in series with the telephone for raising the voltage across the telephone line when the telephone alone is off-hook. In order to trigger the alarm, the telephone must be off-hook and the voltage across the telephone line must be below a threshold value.

Abstract: A system which monitors telephone lines includes the capability to detect abnormal line conditions of many varieties. Such detection capabilities include physical damage such as cut line, misuse such as leaving a handset off-hook for an extended period of time, and intentional abuse such as a wire tap. The system is flexible enough to automatically adjust to varying `normal` conditions. As an aid in providing reliable telephone communications, the system will generate immediate alarms upon detection of abnormal conditions and concurrently create a historical database. This database is used to review reliability and response times, identify hardware failure trends or repeated misuse, and provide system management reports so as to adjust to varying normal conditions without generating false alarms. The physical system contains circuitry to scan the incoming telephone lines.

Abstract: This invention is directed to a device for monitoring the integrity of telephone lines and for warning when the lines are inoperative. The device comprises a monitoring unit which continuously senses the voltage across the telephone lines and generates a control signal which assumes a first value when the lines are operational and a second value when the lines are inoperative. An alarm unit generates a warning signal of an audible frequency when the control signal assumes the second value, and is controlled with a switching unit. The switching unit maintains the alarm unit deactivated when the control signal has the first value and activates the alarm unit when the control signal has said second value.

Abstract: The possibility of corrupting digital data traffic carried by a data line (powered or unpowered), by the connection of a telephone test set to the data line is effectively prevented by augmenting the telephone test set with a mechanism that prevents the test set from asserting an OFF-HOOK condition on the line, unless it has been determined that each of two conditions are satisfied. These conditions are: 1- that no digital data traffic is being carried by the line; and 2- that the electrical voltage condition of the line satisfies a prescribed minimum voltage level criterion. If either of these conditions is not satisfied, a switch circuit installed in the test set's connection path to the line is maintained in a default, open condition, so that it is effectively impossible for the line to be presented with an OFF-HOOK condition through operation of the test set. This default condition remains in effect until both criterion are fulfilled.

Abstract: A method and apparatus for allowing a communication from a calling party (120) to a called party (130) to be monitored by a monitoring party (140) and/or recorded (180, 190). Upon receipt of a communication, the service node (180) of the system reads identification information associated with the communication and establishes a bridge for the communication between the calling party (120) and the called party (130), and establishes a bridge from the communication to a monitoring party (140) and/or to a recorder ( 180, 190) in accordance with the identification information. In response to receiving an indication from the monitoring party (140) to tear down the bridge, the system tears down the bridge. However, the communication remains connected between the calling (120) and called (130) parties. Neither the calling party (120) nor the called party (130) are aware of the monitoring or of the recording of the communication or of the discontinuation of the monitoring.

Abstract: A fax monitoring apparatus includes one or more line interface circuits to simultaneously detect and analyze audio signals produced on any given telephone line by two connected fax machines, analyzing circuitry to analyze and interpret the audio signals to form a compressed fax image, expansion circuitry, to expand the compressed fax image into a bit-mapped image, memory, to store the compressed fax image and/or the bit-mapped image, and display to display the bit-mapped image of the original fax transmission. A method for monitoring and analyzing the activity of a telephone line includes the steps of sampling the voltage of the telephone line to be monitored, calculating the mean value of the voltage from the samplings, comparing the mean value of the voltage with a reference voltage defined as the mean voltage obtained during the previous time interval, replacing the value of the reference voltage with the mean value, and upon activation, recording the activity of the telephone line.

Abstract: A method and apparatus for prohibiting unauthorized use of a telecommunication line is provided. An interference signal is timely generated by the invention on the telecommunication line such that the illegitimate user may not dial the number correctly. Therefore, the invention may prohibit the unauthorized use of a telecommunication line.

Abstract: A switchable order wire circuit installed in addition to a trunk connecting a master station which includes an exchanger and a dependent station in a telephone system. The order wire circuit includes a first telephone terminal located in the master station, a second telephone terminal located in the dependent station, and a pair of telephone lines connecting the first and second telephone terminals. The order wire circuit also includes a hooking detection system installed in the master station, for detecting a hooking operation of the second telephone terminal. In addition, a circuit for switching the telephone lines from the first telephone terminal to a public line when the hooking operation is specifically detected is included.

Abstract: A communication terminal connected to a line of an exchange of a public network, includes a main body of the communication terminal, and a line branching detection controller coupled to the main body. The line branching detection controller includes a communication state detector enabling the communication terminal to call and receive a call when a communication operation of the communication terminal is detected, a line signal monitoring part activated when the communication state detector detects no communication operation and monitoring signals on the line connected to the exchange when activated, and an interference signal generator driven when the line signal monitoring part detects a signal indicating a communication made on the line and generating an interference signal on the line when driven.

Abstract: A ring trip deciding method in a ring trip circuit detects voltage change in the on-hook state and the on-hook state of a terminal when the terminal such as telephone set connected to the telephone line is called.

Abstract: The disclosed invention detects electronic surveillance devices. Should an electronic surveillance device (a bug) be present in a room, the bug will be detecting sounds with a microphone and transmitting on some electromagnetic frequency. In the present invention, these signals are received by a receiver which produces a receiver signal, and a microphone converts the sound present in the room into an electronic reference signal. As may be noted both the received signal from the electronic surveillance device and the reference signal from the reference microphone will have as their source the sounds that are within the room. It is this common sound source of both signals that allows the presence of an electronic surveillance device to be detected. According to the present invention, the phase angle difference between the receiver signal and the reference signal is examined in order to decide if there is any phase correlation.

Abstract: 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.