Abstract: The invention relates to a testing device and a software. The cellular radio system comprises a testing device which is a fixed part of the cellular radio system and operationally connected to a data network. The testing device has a connection over radio path to one or more base stations, and the operational condition of the cellular radio system is examined by means of the testing device by utilising the radio connection of the testing device to at least one base station. In addition, the data network is utilized.

Abstract: The present invention provides a system and method for multi-path simulation that employs a shielded anechoic chamber to avoid external electromagnetic interference and other uncontrollable transmission paths generated in testing, and divides and adjusts a signal into multiple simulation signals to simulate the attenuations and delays generated in multi-path transmission of the signals. The shielded anechoic chamber includes a turntable, controlled by a control unit, for carrying a wireless communication device to be tested and for changing the reception azimuth of the device, thereby measuring the electric wave transceiving of the device.

Abstract: A circuit testing approach involves configurable switch control for automatically detecting and routing test signals along a plurality of test circuit paths. According to an example embodiment of the present invention, a configurator arrangement (100) is programmed to control a configured circuit (110), the control including automatically setting switches (115) on the configured circuit. In one implementation, the configurator arrangement is programmed to automatically detect test signals (i.e., digital and/or JTAG test signals) and to control switches (115) for routing test data along a test circuit path. With this approach, manual switching for routing the test signals is not necessary, which has been found to be useful in applications where access to the circuit paths for switching is difficult or impossible.

Abstract: Method and system for implementing an inter-domain constraint-based shortest path first (“IrD-CSPF”) technique for supporting hierarchical routing in interconnected multi-domain OTNs are described. In one embodiment, the invention is a method for calculating a network path in an interconnected multi-domain network. The method comprises receiving a path setup request message for a new traffic flow in the network identifying a source node in one domain of the network and a destination node in a second domain of the network; determining a common ancestor hierarchical routing domain that includes ancestor nodes of both the source and destination nodes; calculating an inter-domain path from one ancestor node to the other ancestor node that determines, for each lower-level domain, border nodes in the domain from the source node to the destination node; and for each bottom-level domain, calculating an intra-domain path between the border nodes that were determined for the domain.

Abstract: A system and method for generating a switch-based C/I matrix for a wireless network is provided. A cell-under-test (CUT) may broadcast system unique carrier and interference signals to mobile stations serviced by the CUT and mobile stations serviced by measurement sectors of other cells in the wireless network. The mobile stations make downlink signal strength measurements, and transmit the signal strength measurements to the corresponding sectors and CUT that service the mobile stations. The measurement sectors may be further configured to measure signal strength of the interference signals transmitted from the CUT on the uplink. The signal strengths are then processed to generate the switch-based C/I matrix.

Abstract: A method and apparatus are provided for low latency loss-free burst switching. Burst schedules are initiated by controllers of bufferless core nodes and distributed to respective edge nodes. In a composite-star network, the burst schedules are initiated by any of a plurality of bufferless core nodes and distributed to respective edge nodes. Burst formation takes place at source nodes and a burst size is determined according to an allocated bitrate of a burst stream to which the burst belongs. An allocated bitrate of a burst stream may be modified according to observed usage of scheduled bursts of a burst stream. A method of control-burst exchange between each of a plurality of edge nodes and each of a plurality of bufferless core nodes enables burst scheduling, time coordination, and loss-free burst switching. Both the payload bursts and control bursts are carried by optical channels connecting the edge nodes and the core nodes.

Abstract: Methods and apparatus provide single or multi-port, flexible, cost-effective, built-in self-test capabilities for network communications equipment, such as for example switches, and programmably generate, and subsequently analyze, one or more sequences of test packets, wherein the test packets simulate at least two flows of traffic. Such test packets can have programmable headers, payloads, and duty cycle. A line card embodying the present invention may generate its own traffic pattern, which may be similar or identical, to traffic patterns observed on Internet backbones. These traffic patterns may contain a bimodal distribution of control packets interspersed with data packets wherein the control packets and data packets are relatively short and long respectively. A plurality of test packet generators/receivers can be deployed in a network communications device having a plurality of ports. In such a configuration, test generator/receiver is associated with each of the plurality of ports.

Abstract: A telecommunication multi-service transport platform system is disclosed. It has at least one service card providing a predetermined telecommunication service, and at least one protection card for replacing the service card when the service card fails. The protection card further comprising one or more test ports connectable to an external testing tool, one or more protection circuits, and at least one relay module associated with the test ports for allowing the testing tool to be connected to the protection circuits through at least one test port for testing the service card when the protection card is in a standby mode and for disconnecting the testing tool from the protection circuits when the service card fails.

Abstract: A method of configuring a SONET network element to support a test head test session comprises dedicating an otherwise assignable output port of a SONET network element as a test access port, receiving a request to connect a connection switched by a switch fabric of the SONET network element to the test access port, determining whether the request is associated with a test head; and, if the request is associated with the test head, provisioning the switch fabric to connect the connection to the test access port.

Abstract: A network is disclosed for interconnecting devices external to the network. Embodiments of the network include a plurality of switching nodes interconnected by links forming or capable of forming a Gamma graph interconnection network. Devices are coupled to the network via a plurality of ports. Furthermore, the network includes a plurality of Infiniband buses with each switching node coupled to at least one of the buses. Each Infiniband bus is capable of supporting a configurable number of ports such that the bandwidth of a port is inversely proportional to the number of ports configured per bus. The Gamma graph interconnection network of the router providing for high port counts and increased bandwidth availability. Furthermore, the use of industry standard buses, such as Infiniband buses, allow for the interconnection of multiple heterogeneous application specific modules to interface and communicate with one another.

Abstract: Methods and associated hub arrangements are described for use in diagnosis and recovery in high performance digital loops such as, for example, those seen in Fiber Channel systems. In one system having a hub configured for interconnection of a plurality of stations as part of a digital system such that digital data flows between the stations based on operational status of the system, an arrangement forms part of the hub which arrangement is connectable at points within the hub and between at least two different pairs of the stations for monitoring certain characteristics of the data in a way which provides for non-invasive identification of one or more conditions related to the operational status of the system.

Abstract: The present invention is an apparatus for multi-level loopback test in a community network system and method therefor, in which a loopback test device is installed between an Ethernet switch in a community and a central office so that the loopback test device can be utilized by network management system in central office to perform a three-level loopback test on the community network system to easily obtain the information of whether there is a fault between central office and loopback test device, whether the connection of Ethernet switch is good, and whether loopback test device operates normally.

Abstract: An audio test system for analyzing and quantifying audio data losses during network-based telephony sessions between communication devices such as telephony-enabled computers and Internet telephones. A transmit device converts an input audio signal to a stream of data packets and communicates the data stream over a network to a receive device. The receive device converts the data stream to an output audio signal. An audio analyzer is coupled to the transmit device and the receive device to monitor and capture the input audio signal and the output audio signal. The audio analyzer determines transmission qualities for the session, such as data loss and latency, by generating and comparing envelope waveforms of the input audio signal and the output audio signal.

Abstract: A base station receives a signal resulting from multiplexing a communication signal spread using a signal-specific spreading code and sent by mobile station apparatus and a calibration (CAL) signal spread using a signal-specific spreading code and sent for each unit frame for a predetermined time by a CAL radio signal generator in a same frequency band. An A/D conversion/despreading section and an A/D conversion/despreading section extract the communication signal and CAL signal from the received signal. A calibration processing section carries out calibration processing using the CAL signal in parallel with a communication using the communication signal. An array combining/signal processing section carries out demodulation processing on the communication signal using the calibration processing result.

Abstract: A communication apparatus which effectively optimizes the route for each call connection without causing any adverse effect on other existing sessions and thus contributes to better quality and reliability of telecommunications services. A source-side routing data manager collects information necessary for path calculation, evaluates every possible path with the collected information, and manages routing data that is obtained through the path evaluation. A source-side best path finder selects a best path from among those listed in the routing data. A connection releasing unit releases a particular connection when the source-side best path finder has found a new best path that is more suitable for that particular connection than the current path, while maintaining the connectivity of other existing calls. A new best path setting unit performs a call connection procedure by using the newly selected best path, after the connection releasing unit has released the current connection.

Abstract: A test set includes at least one signal input port, a test circuitry, a processor, a user-input device, and a display. The test circuitry couples to and receives signals from the at least one signal input port. The test circuitry then generates test data corresponding to the received signals. The processor couples to and receives test data from the test circuitry and generates test results. The processor also couples to and receives commands from the user-input device. The processor further operatively couples to the graphical display that receives and displays the test results from the processor. In one embodiment, the test set is capable of performing line qualification and connectivity testing. A modem module can be used to facilitate connectivity testing. The modem module can be a plug-in module with a common interface to the test set. The modem module can also contain a fingerprint value that identifies the module type and the software revision number to the test set.

Abstract: A method of multi-protocol call trace on GPRS Gb and Gr interfaces of a GSM network uses distributed processing. Probes are situated at locations where measurements are desired in a monitored mobile network, such as at Gb and Gr interfaces, and are connected in a non-intrusive manner to the mobile network. A remote server is coupled to each probe over a local area network (LAN) to process data as it is acquired by the probe. The probe and remote server are coupled to a central server via a wide area network (WAN), as are client servers. The remote servers manage the probe data (packet data units—PDUs) in real time to create appropriate transactional and raw data indices that are stored locally with the PDUs. Call/procedure trace applications are initiated from the client servers and disseminated by the central server to the remote servers.

Abstract: The invention provides a communication control device that includes a self-diagnostic test circuit capable of executing an operation test. The communication control circuit includes a PHY circuit on an LSI with little trouble, and at a operating speed that is equivalent to actual operation. The self-diagnostic test circuit includes: test data creation circuit for creating test data; expected value data creation circuit for creating expected values of the test data after processing; an arbitration signal switching circuit that switches arbitration signals such that test data supplied from the output driver can be received by a receiver of the same twisted-pair drive block as the output driver; and a comparison circuit that compares test data supplied from an output driver and received by a receiver of the same twisted-pair drive block as the output driver with the expected value data and creates match flags.

Abstract: A PBX switch incorporates methods and apparatus for automatically configuring Call Appearance values in an ISDN BRI. The methods and apparatus include providing means for one PDN to call the other PDN in the same BRI, recording the Call Appearance data for the first call, placing the first call on hold and calling the same number again, recording the Call Appearance data for the second call, and repeating the process until all Call Appearance values have been recorded. According to the invention, the process is repeated for both PDNs in each BRI coupled to the PBX switch.

Abstract: A test set includes at least one signal input port, a test circuitry, a processor, a user-input device, and a display. The test circuitry couples to and receives signals from the at least one signal input port. The test circuitry then generates test data corresponding to the received signals. The processor couples to and receives test data from the test circuitry and generates test results. The processor also couples to and receives commands from the user-input device. The processor further operatively couples to the graphical display that receives and displays the test results from the processor. In one embodiment, the test set is capable of performing line qualification and connectivity testing. A modem module can be used to facilitate connectivity testing. The modem module can be a plug-in module with a common interface to the test set. The modem module can also contain a fingerprint value that identifies the module type and the software revision number to the test set.

Abstract: Methods and associated hub arrangements are described for use in diagnosis and recovery in high performance digital loops such as, for example, those seen in Fiber Channel systems. In one system having a hub configured for interconnection of a plurality of stations as part of a digital system such that digital data flows between the stations based on operational status of the system, an arrangement forms part of the hub which arrangement is connectable at points within the hub and between at least two different pairs of the stations for, monitoring certain characteristics of the data in a way which provides for non-invasive identification of one or more conditions related to the operational status of the system.

Abstract: Channel-to-channel communications is provided by integrating channel-to-channel functionality into one or more communication channels of a computing environment which may include heterogenous computer systems. The one or more channels having the integrated CTC function are non-dedicated channels also capable of conventional channel functionality. Work units at such channels are forwarded to either the CTC function or the channel function based on work unit type. Further, a facility is provided for automatically deciding which of the first channel and the second channel is to provide the CTC function for a CTC connection. Partition-to-partition communication can also be accomplished using the integrated CTC function by establishing an internal logical path between a first logical partition and the CTC function and a second logical path between a second logical partition and the CTC function.

Abstract: A test device to isolate and locate problems in a wireless transmission antenna system by selectively inducing multiple faults in an independent integral configuration. The test device is used in conjunction with test analysis equipment allowing a technician to induce independent multiple faults system test configurations to detect, isolate and locate feed line and antenna system problems. By selectively connecting the test device at different points along the transmission path dependent on the test analysis outcome, the exact physical location of the problem can be determined within the transmission circuit.

Abstract: A communications quality measurement system for use with packet and other networks comprises a test signal transmitter, a test signal receiver, and a test signal analyzer. A test transmitter is used to produce a series of test signals selected or engineered for measuring one or more desired Quality of Service or other performance parameters of a network path to be tested. A first copy of the test signal is transmitted via a reference path of known characteristics and with minimal impairments. A second copy of the test signal is transmitted via the network path to be tested. A test receiver receives and records the signals which were carried via the reference and test paths. A test signal analyzer compares the signals received over the reference and test paths and analyzes differences to determine Quality of Service or other parameters, such as Bearer Delay, Cell or Packet Loss, Echo Delay, and Echo Amplitude, some of which are directed to the particular impairments that are characteristic of packet networks.

Abstract: An intelligent apparatus comprises a master module and a plurality of slave modules each having a CPU, a control circuit and an associated software, wherein each of the slave modules is in communication with the master module, and the CPU of the master module may control the CPUs of the slave modules respectively to form a single system. When the master module detects that a monitoring device coupled to a single user I/O interface installed in the apparatus is performing network monitoring and management with respect to a certain module, the CPU of the master module may transfer an access right of the user I/O interface to the certain module by closing or opening switches installed in the master modules enabling the certain module to receive the access signal from the user I/O interface by closing a switch thereof.

Abstract: A feedback-based adaptive network is described wherein at least a portion of the network elements report operating information relating to network conditions to a centralized data store. The information which is reported to the data store is analyzed by a policy engine which includes a plurality of application specific plug-in policies for analyzing selected information from the data store and for computing updated control information based upon the analysis of the information. The updated control information is fed back to selected network elements to thereby affect operation of the selected elements. Typically, when the operation of a network element has been affected, its corresponding operating information will change. The new or changed network element operating information is then reported to the data store and analyzed by the policy engine. The policy engine may then generate new or updated control information for affecting the operation of selected elements in the network.

Abstract: A technique for verifying an intermediate node that employs a forwarding plane and optionally a control plane. A test packet is generated and transferred to the forwarding plane. Using operational software and hardware, the forwarding plane forwards the test packet to a line card, which in turn “loops” the test packet back to the forwarding plane. Using operational software and hardware, the forwarding plane processes the looped-back test packet including forwarding the packet to a destination, such as a control plane, where the looped-back test packet is verified.

Abstract: A radio communication system control method, a radio communication system, and an information processing apparatus used therein is one where system a server and terminals are linked via a plurality of base stations. The radio communication system is configured to prevent communication errors. When the link between a server and a base station is disconnected, the server detects the disconnection, and transmits, to a base station adjacent to the base station, a power supply off command for disconnecting the power supply in the base station. By transmitting the command to the base station via the base station, the server disconnects the power supply in the base station and stops the communication between the base station and a radio terminal apparatus.

Abstract: A novel method of providing an external host processor with access to registers located in different clock domains. The method comprises the steps of translating host processor interface signals into internal register interface signals, and performing handshaking with the registers via the internal register interface. The handshaking includes supplying registers with a register access signal for enabling access to a selected register, and producing a register ready signal in response to the register access signal. Synchronization signals delayed with respect to the register ready signal may be used for synchronizing registers located in different clock domains with the processor interface.

Abstract: A system for probing one or more SVCs that enables a network manager station to setup a probe event in advance before a SVC is created. Upon the creation of the SVC, the data is captured and sent to the network management station without any further intervention required. In a first stage, a SVC originator is configured with a probing IE containing parameters to be included in the SETUP request message when SVCs are established. A unique identifier is included as one of the parameters in the probing IE and is used by the probing switch to detect a SVC that is to be probed. A PVC is established to the switch containing one or more SVCs that are to be probed. A probing port is configured on the switch and a range of VPI/VCIs are assigned to the port. A multicast connection is configured in the switch and traffic from the SVC originator is directed toward both the destination and to the probing port. In this fashion, the SVC traffic can be analyzed using diagnostic tools located remotely anywhere on the network.

Abstract: Data frames or packets transmitted between stations on a selected channel from amongst a plurality of channels in a wireless communication network are captured, along with data frames or packets transmitted on other of the plurality of channels that appear on the selected channel due to crosstalk caused by channel overlap, are filtered to separate the data frames or packets originated on the selected channel from these due to crosstalk, for presentation to a user in respective individual traces or screen displays.

Abstract: A technique for detecting and responding to a loopback condition on an ISDN PRI of a telecommunications switching system. The technique involves storing the Call Reference Value of the most recently transmitted call SETUP command as the Last Sent CRV. An incoming call SETUP command is considered to have looped back when it is assigned a Call Reference Value identical to the Last Sent CRV, and it requests a PRI channel that is occupied. The PRI is considered to be in a loopback condition after a predetermined number of call SETUP commands have looped back. The PRI can be removed from service while the loopback condition persists.

Abstract: A frame relay network has a network management system in combination with frame relay nodes. The network management system provides frame relay oversubscription trunk and connection parameter signals to the frame relay nodes. The network management system uses a graphical user software interface program for receiving frame relay oversubscription trunk and connection parameters from a network supervisor that are formatted into the frame relay oversubscription trunk and connection parameter signals. The frame relay nodes respond to the frame relay oversubscription trunk and connection parameter signals, and at least one frame relay node provides a frame relay oversubscription connection control signal containing connect level parameters to another frame relay node when relaying communication signals from one frame relay node to another frame relay node. In operation, the trunk line has multiple virtual connections communicating the frame relay oversubscribed data between the frame relay nodes.

Abstract: A bit error rate test (BERT) system is configured as a field programmable gate array that emulates multiple independent BERT generators. The BERT generators produce test frames containing test pattern codes associated with respectively different time division multiplexed (TDM) digital communication channels, that are not necessarily mutually contiguous within a plurality of TDM timeslots of a network communication frame serving digital communication circuits. A framing unit assembles the test code patterns into a test frame and transmits the test frame over a serial network interface to a plurality of digital channel units of a channel bank. The framing unit also interfaces contents of test code patterns within test frames returned from the channel units over the serial network interface with a plurality of data channel-specific virtual BERT receivers, associated with respective digital communication channels.

Abstract: Based on the results of the detection of a unique word in a received signal with a unique word detecting portion and the detection of a correct CRC in a received signal with a CRC calculating portion, a microprocessor portion sends a reset signal to a timer portion. The reset signal resets the timer of the timer portion, and causes the timer portion to send a field strength measurement timing signal to a field strength measuring portion. The timer portion then automatically keeps track of the data slot timing and outputs the field strength measurement timing signal at every cycle of desired time-slot. Thus, the reliability of measuring the field strength of received radio wave for the desired station in a time-division multiple access can be improved, even if there is interference from other stations.

Abstract: The present invention relates to a detector comprising a microprocessor so that when a test item is inputted through an input device, the microprocessor is activated to read the test item and writes an identification (ID) of a user device or telecommunication device of CO corresponding to the test item into a VDSL chipset of the detector, which is used to simulate a virtual user device or telecommunication device of CO and enables the microprocessor to send a packet to telecommunication device of CO or user device for test, and quickly find out whether there is a line interruption or poor quality communication between telecommunication device of CO and user device.

Abstract: The invention relates to a communication system with at least two communication nodes for the transmission of information via a common transmission medium in a time division multiplex process.

Abstract: A protocol test device has at least two channels which each have a transmit and a receive side, the protocol test device being designed to switch a signal transmitted from a first channel to the receive side of a second channel. A method for determining, by approximation, a transmit time of a data package in the protocol test device includes the following steps: a) transmitting a signal via the transmit side of the first channel, b) forwarding the signal to the receive side of the second channel, and, c) in the receive side of the second channel allocating a time stamp to the signal.

Abstract: A transmission system is provided. The system includes a hardware monitor adapted to collect performance information about associated hardware components, a system information database adapted to refresh based on the collected performance information and to generate system status information, and a hardware controller adapted to selectively communicate alarm change messages to one or more of the hardware components based on the collected performance information and the system status information.

Abstract: In a telephone communication system employing a lower spectral band and a higher spectral band for communication of voice and video, wherein the system includes a first line for carrying signals at both the first and the second spectral bands and a second line for carrying signals at only the second spectral band, and wherein capacitors are employed for connection of the second line to the first line for exclusion of DC at a signal splitter of the communication system, the system has a bypass DC signal path for an alternative connection of the second line to the first line in substitution for the connection of the capacitors. The bypass can be activated electronically and remotely to establish conditions for the conduction of test of the signal carrying lines.

Abstract: A method of monitoring the integrity of the path and flow of digital PCM data from a source end to a receiving end which includes generating a pseudo-random sequence of bits at the source end, transmitting the pseudo-random sequence of bits together with the PCM data through a transmission path to a receiving end, and applying the pseudo-random sequence of bits to a pseudo-random bit sequence checker at the receiving end.

Abstract: A multifunctional apparatus transfers and receives facsimile data and communication data by using an integrated service digital network constructed with a computer interface conducting facsimile and communication data; a line interface transferring data to the network and receiving facsimile and communication data from the network at the first transfer rate; an ISAC controlling a connection with the integrated service digital network, conducting facsimile and communication data via the network, converting the transfer rate of data received from the network to a second transfer rate, and converting the transfer rate of data received from for the network to the first transfer rate. A serial I/O converts the communication data transmitted from the computer through the computer interfacing section, and facsimile data scanned in a scanning section, into serial data, and transfers serial data to the ISAC, and receives communication and facsimile data from the network via the ISAC.

Abstract: A physical layer transceiver of a home network station connected to a telephone medium has an architecture enabling adaptation of detection circuitry based on received network signals to enable reliable recovery of data signals. The physical layer transceiver includes an input amplifier that amplifies network signals according to one of 128 gain settings set by a receiver gain control signal. A signal conditioning circuit includes an envelope detector configured for outputting an envelope of the amplified received signal, and an energy detector configured for outputting an energy signal of the amplified received signals. The envelope signal and the energy signal are supplied to slicer threshold circuits, configured for outputting noise, peak, data event and energy event signals based on noise threshold, peak threshold, data transition threshold, and energy threshold signals, respectively.

Abstract: A mediation system for a telephone network. The telephone network includes a plurality of signaling service points (SSPs) communicating message signaling unit (MSU) data with a plurality of signal transfer points (STPs). The MSU data is routed on data links connecting the plurality of SSPs and STPs. The mediation system includes a probe and a mediator. The probe is connected to at least one of the data links for intercepting the MSU data routed on the one data link, and the mediator is coupled to the probe for collecting the MSU data generating a call detail record (CDR). The probe intercepts either A-link data and/or E-link data on the data links. The mediator correlates the MSU data against a call list and generates either a full CDR or a partial CDR depending on a mode selected by a user of the system.

Abstract: A system, device, and method for evaluating dynamic range in a communication system utilizes a narrow band multiple tone test signal for emulating a wide band composite signal equivalent to the symbol rate bandwidth of a digitally modulated carrier. The multiple tone test signal is constructed such that a significant portion of the third order intermodulation distortion products fall within the channels adjacent to the test channel so that the dynamic range can be evaluated with a commercially available industry standard CATV analyzer using a standard adjacent channel power measurement technique.

Abstract: A method and system for testing trunks and modems of communication lines includes identifying a trunk and a modem in a communication line from trunk signaling (SS7) data. Historic performance data of the modem in the communication line is then measured. The historic performance data includes the time the modem is connected with the trunk, the speed at which data is communicated through the modem and the trunk in the communication line, and the rate at which the modem connects with the trunk. The performance data of the modem is then correlated with the trunk signaling data to associate the performance data of the modem with the trunk in the communication line. The performance data of the modem is then analyzed to determine if the communication line is operating improperly. The analysis is performed to determine whether the trunk or the modem is operating improperly.

Abstract: A system for monitoring a CDMA-type mobile terminal device, includes (a) a CDMA base station system, (b) a CDMA core network connected to the CDMA base station system through wires, (c) a server which monitors the CDMA base station system connected to the CDMA core network through wires, (d) a monitoring device connected to the server through wires, the monitoring device monitoring and controlling the CDMA base station system through both the server and the CDMA core network, and (e) a CDMA-type mobile terminal device connected to the CDMA base station system through radio signals.

Abstract: A network testing system (50) includes a message compiler (52) accepting a plurality of data inputs (54) to create a test message (56). A communicator (58) is capable of transmitting the test message (56) to a component under test (60). The test message (56) is compliant with any of a plurality of protocols. The communicator (58) is also capable of emulating a communication session using an emulation module.

Abstract: The invention provides a cost-effective system and method for testing telephone lines connected to transmission systems, such as Subscriber Line Multiplexer systems. The invention uses the same pair of wires for transmission and test. According to one embodiment of the invention, a system for allowing a test procedure to be performed on a communication system is provided. The communication system has a transmission line for connecting to telephone exchange and a subscriber line for connecting to a communication set. In the system of the invention, a detector is coupled to the transmission line for detecting test signals on the transmission line. A bypass circuit is coupled between the transmission and subscriber lines for allowing the test signals to bypass the communication system. Also, a discriminator is coupled to the subscriber line for discriminating a connection status of the communication set.

Abstract: A two-ended, line-driving and receiving/tone signal analysis system performs line connection verification applying a low-distortion, low-amplitude test signal to one end of a cable pair under test and monitoring the response of a remote end wireline pair. Preferably the test signal frequency is on the order of 110 Hz, which avoids domestic and foreign AC power signal frequencies and is spectrally equidistant from their harmonics. It also avoids ringing frequencies for POTS lines, and remains safely below the 350 Hz lower limit of POTS and other telephone line system services. In response to application of the 110 Hz test signal to tip and ring segments of a wireline pair at one end of the cable bundle, the energy of the 110 Hz component, as well as that of two other ‘spectrally nearby’ (slightly higher at 112 Hz and slightly lower at 108 Hz), are measured at a tip and ring pair at the far end of the cable plant.