Harris Corporation

Fluke Corporation

Michael F Kennedy

Onofrio Schillaci

Paul H Katz

Roy Lujan Soto

Edward K Siu

Ben A Pierce

Alan Blair Lowell

Joseph A Potts, Jr

Laura E Moser

Kenneth S Gold

Clinton J Wooton

Glen Holt Humphrey

Randall M Wagner

Alex Knight

James W Lester

Joseph E Barron

Derek G Foster

Aaron Chan

James D Coleman

Randy A Callaway

David W Keefe

Jeffrey W Hearsey

Chong Yi

A multi-unit test system performs automated and dynamically alterable, double-ended testing of telephone lines, whose service is provided on copper cable pairs. A prescribed set of (e.g., twelve) individual tests are executed either from a hand-held measurement unit, or by a central office-resident direct access test unit, or by a collaboration of the two. The hand-held measurement unit and the direct access test unit exchange FSK-based test control messages with one another that are effective to cause a selected electrical condition to be applied to a first portion of the wireline and to cause a prescribed electrical measurement to be made at a second portion of the wireline.

Dynamic, automated double-ended system and method for testing and qualifying metallic telecommunication loops

An ISDN test set employs a user selectable dialing mechanism, that allows the test set user to select from multiple types of dialing&#x2014;overlap dialing and enbloc dialing, through the use of a simplified functional dialing key set. The dialing key set, in combination with dialing software employed by the test set's supervisory control processor, provides the user with substantial ISDN dialing flexibility, while reducing interaction between the user/craftsperson and the test set, that minimizes dialing inaccuracies that often depend upon the skill and familiarity of the technician with ISDN communications. Enbloc redialing (of the most recently dialed number) or of a stored number in memory is provided only in ON-HOOK mode by the operation of a REDIAL or RECALL key. Otherwise (whenever OFF-HOOK) only overlap mode dialing is employed.

User selectable overlap and enbloc dialing of ISDN line

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. If the magnitude of a Fourier component of the received 110 Hz test signal for a Fourier correlation operation cycle (FCOC) is more than a prescribed differential greater than the magnitudes of the two nearby frequencies, it is inferred that the remote tip and ring pair is the same wire pair as the wireline pair at the one end of the cable, thereby identifying the two ends of the same wireline pair.

Two-ended wireline pair identification system

An ISDN test set employs a user selectable dialing mechanism, that allows the test set user to select from multiple types of dialing&mdash;overlap dialing and enbloc dialing, through the use of a simplified functional dialing key set. The dialing key set, in combination with dialing software employed by the test set's supervisory control processor, provides the user with substantial ISDN dialing flexibility, while reducing interaction between the user/craftsperson and the test set, that minimizes dialing inaccuracies that often depend upon the skill and familiarity of the technician with ISDN communications. Enbloc redialing (of the most recently dialed number) or of a stored number in memory is provided only in ON-HOOK mode by the operation of a REDIAL or RECALL key. Otherwise (whenever OFF-HOOK) only overlap mode dialing is employed.

A portable ISDN test set contains test circuitry that is controllably operative to automatically test the ISDN communication capability of an ISDN circuit. In response to a user operating a prescribed input/output element of a user interface of the test set, the test set's supervisory control processor executes a routine that places an ISDN call over a first bearer channel of the ISDN circuit, the first bearer channel having a first directory number, through a public switched telephone network to a second directory number associated with a second bearer channel of the ISDN circuit. The ISDN call is thus routed by the public switched telephone network back to the ISDN test set. When the ISDN call is received by the test set, it is automatically looped to the public switched telephone network, so that the call is rerouted to the first directory number associated with the first bearer channel to the ISDN test set. When the looped back call is answered, a BERT is conducted over the dual looped bearer channel pair, thereby testing the full 128 Kbps bearer channel bandwidth of the ISDN circuit. The automated testing routine includes a subroutine that automatically derives the first and second directory numbers from respective user-supplied service profile identifiers for the first and second bearer channels.

Call yourself BERT testing of ISDN line

A device and method for testing a telephone circuit in which a caller takes advantage of available caller identification information to complete a ringback test without resort to potentially costly and overused toll trunks. The ringback test device is accessed by a caller (subscriber or craftsperson) who may not be aware of the telephone number from which he is calling when the caller completes a call to a telephone number assigned to the device. As the caller is accessing the test device, the test device detects the caller identification available between the first and second rings to identify the caller's telephone number, and answers the call after the second ring. The test device presents the telephone number to the caller, and the test device may thereafter be used to complete a ringback test to the identified telephone number. The caller ID information may also be display-formatted at the test device and provided to a caller's visual display.

Telephone ringback test device and method

The control software of a central office-installed ringback test device is augmented to allow a craftsperson to test the operability of a caller identification, call-waiting (CIDCW) class of service of a line, without participation of another technician at the central office. Rather than instructing the craftsperson to go back in-hook, the SASS's microcontroller maintains the trunk circuit through which the incoming call is coupled to the SASS in a suspended, continuously monitored state, so as to effectively busy out the calling line. The SASS then places a return call to the calling number by way of the ringback line, which by-passes the trunk, to the central office switch. If the line circuit from which the call is being placed is equipped with CIDCW class of service, the incoming call from the SASS will exercise its functionality--including providing a ringing signal back to the SASS, and an indication to the calling technician of another call, including the originating telephone number of that call--but it will not return a busy tone to the SASS. If the SASS receives busy tone, it knows that the line of interest is not properly equipped with CIDCW class of service.

Method for testing call waiting, caller ID functionality of telephone

A multi-ported, caller ID-based test unit is installable in the central office of a public switched telephone network. The test unit is capable of determining the telephone number, subscriber name and various other information associated with the subscriber line used to access to the test device, and is operative to conduct various tests of a telephone circuit from which a call to the test device is placed. These tests include exercising a caller identification, call waiting class of service, testing the ability of the telephone circuit to receive incoming calls, and testing the operation of a message-waiting indicator of a telephone unit coupled to the telephone circuit, as well as the ability to conduct a data session with a remote terminal using the test unit's data port.

Multi-port caller ID-based telephone ringback test device

A multi-ported, caller ID-based test unit, which may be installed in the central office of a public switched telephone network, is capable of determining the telephone number, subscriber name and various other information associated with the subscriber line used to access to the test device, and is operative to conduct various tests of a telephone circuit from which a call to the test device is placed. These tests include exercising a caller identification, call waiting class of service, testing the ability of the telephone circuit to receive incoming calls, and testing the operation of a message-waiting indicator of a telephone unit coupled to the telephone circuit, as well as the ability to conduct a data session with a remote terminal using the test unit's data port.

A processor-controlled integrated telephone line measurement and conditioning apparatus installable at a remote site provides a multiplicity of measurement and conditioning functions that are selectively executable in response to commands issued from a supervisory command site. The dual measurement and conditioning capabilities of the architecture of the present invention impart both remote measurement unit (RMU) functionality and metallic access unit (MAU) functionality that may be individually accessed and controlled. The RMU operates primarily as a test head that performs mechanized loop testing (MLT) tasks, while the MAU is operative to impart prescribed electrical conditions to a specified line circuit. When controllably accessed to operate as an RMU, the present invention responds to instructions from a command site (loop maintenance operations systems) and performs single-line demand tests on a line provided by a pair gain system. To operate as an MAU, the system receives commands from a direct access test unit (DATU) and performs line conditioning functions on the test line provided by the pair gain system.

Remote measurement unit containing integrated line measurement and

A remote test unit for testing and conditioning one or more telephone lines includes multiple electronically erasable flash memory banks, which contain respective versions of the operating system employed by the test unit's micro-controller. An operating system modification routine employed by the host processor of a remote site allows the functionality of the remote test unit to be selectively modified by electronically installing an upgraded or downgraded version of the operating system, or by electronically selectively activating or deactivating one or more operational features of the currently active operating system.

User-controlled electronic modification of operating system firmware

An autobaud detection mechanism, installed as part of the communication control software of a serial communication device's microcontroller, enables the device to automatically determine the baud rate employed by a remote digital data communications device. Starting with a default baud rate, corresponding to the highest available baud rate, the mechanism steps through successively lower baud rates in the course of a search for the baud rate at which the remote device is transmitting. When an incoming call is received, respective bits of the received data are examined for the presence of transmission errors. If a transmission error is detected, the baud rate is stepped to the next lowest baud rate. If no error is detected, the received data bits are compared with a reference character. If the two compared data bit patterns match, the controller locks the baud rate at that baud setting for the remainder of the call. When the call is terminated, the baud rate reverts to its default setting. If the bit pattern comparison does not indicate a match, the baud rate is stepped to the next lowest baud rate. When the autobaud detection routine has stepped to a new baud rate entry, it initiates a prescribed time-out as a safeguard against the receiver becoming `out-of-sync` with a transmitter. Once, the lowest baud rate has been reached, the routine steps to the default setting and starts again.

Autobaud rate detection mechanism

A remote measurement unit for testing and conditioning one or more telephone lines includes multiple electronically erasable flash memory banks, which contain respective versions of the operating system employed by the test unit's micro-controller. An operating system modification routine employed by the host processor of a remote site allows the functionality of the remote test unit to be selectively modified by electronically installing an upgraded or downgraded version of the operating system, or by electronically selectively activating or deactivating one or more operational features of the currently active operating system. A reset routine ensures that the operating system modification mechanism will only boot up the `correct` one of the two quasi-redundant systems available to the RMU's microcontroller after a system modification has been performed. In addition, the temporary insertion of a no-op code field just prior to the beginning of the program prevents the RMU's processor from accidentally booting up a modified system until the system has been verified as operational.

Local/remote modification of electronically alterable operating system

A door phone controller has a door ajar feature for alerting a user that a door was left open. The door phone controller accommodates the door ajar feature in several different ways depending upon how it is configured to interface with the central office line. If the door phone controller is configured to interface with the central office line as an individual station, then when a door is left open, the controller alerts the user via auxiliary alert contacts specifically provided for activating a customer chime. When the door phone controller is configured as a ring-down station, the door phone controller alerts the user that the door was left ajar by dialing a pre-programmed telephone number and sending a door ajar tone. If the door phone controller is configured as an interface with a trunk port, then when the door is left open, the controller alerts the user by ringing the trunk line and also energizing the auxiliary alert contacts. The user can both enable and disable the door ajar features via the telephone interface.

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Ojai, CA, United States of America

Michael F Kennedy