Abstract: A device and methods for automatically diagnosing impairments in a digital quadrature amplitude modulated signal is disclosed. The impairments include phase noise, compression, coherent interference, and non-coherent interference. The device comprises a phase noise detector, a compression detector, and an interference detector. The phase noise detector detects phase noise by analyzing data points of an amplitude quadrature modulated constellation for orthogonal deviations from ideal points. The compression detector detects compression by analyzing the magnitudes of vectors from the constellation's origin to data points of the constellation. The interference detector detects coherent and non-coherent interference by detecting error signals in the data points and then analyzing the distribution of the error signals.

Abstract: A test system comprising: acquiring an upstream channel descriptor list; entering a pause network state when the upstream channel descriptor list is completed; and selecting a particular channel from the upstream channel descriptor list before exiting the pause network state.

Abstract: A system for testing a portion of a cable network provides a pattern generator, addresser, forward error corrector, and comparator. The system is particularly adapted to testing the upstream channel in a cable network. The pattern generator generates a test signal. The addresser addresses the signal to a known server and also instructs the known server to return the test signal to the test system. The forward error corrector corrects errors introduced in the test signal in transmission from the known server to the test system. The comparator then compares the returned test signal to the originally transmitted test signal to determine the performance of the back channel. Preferably, the comparator uses a bit error rate test to determine the performance of the back channel.

Abstract: A system for testing a portion of a cable network provides a pattern generator, Addresser, forward error corrector, and comparator. The system is particularly adapted to testing the upstream channel in a cable network. The pattern generator generates a test signal. The addresser addresses the signal to a known server and also instructs the known server to return the test signal to the test system. The forward error corrector corrects errors introduced in the test signal in transmission from the known server to the test system. The comparator then compares the returned test signal to the originally transmitted test signal to determine the performance of the back channel. Preferably, the comparator uses a bit error rate test to determine the performance of the back channel.

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: An Internet accessible test system including: providing a remote client having an Internet connection; and exercising a tester function across the Internet connection by the remote client.

Abstract: A communication signal characteristic measurement system comprising: detecting a quiet line including: storing a specific characteristic data, detecting a vertical synchronization pulse in the specific characteristic data, and applying an eight line delay in the specific characteristic data; and displaying a data set showing the quiet line relative to the vertical synchronization pulse.

Abstract: A method for optical spectrum analysis provides a tunable optical filter and scans a wavelength range of an optical signal that is larger than the free spectrum range of the tunable optical filter. The optical signal is filtered through the tunable optical filter. Separate multiple optical orders of the wavelengths scanned and filtered by the tunable optical filter are individually detected.

Abstract: A wavelength measurement or monitoring system provides a tunable Fabry-Perot optical filter. At least one known light source is used to calibrate and correlate separate wavelength bands scanned by the tunable Fabry-Perot optical filter. At least one wavelength reference is utilized to calibrate at least one wavelength band of the tunable Fabry-Perot optical filter. The wavelength reference is transferred to a wavelength band that is identified for measurement when the wavelength reference is not in a wavelength band identified for measurement by the tunable Fabry-Perot optical filter. An unknown optical signal is scanned through the tunable Fabry-Perot optical filter. The wavelengths in the unknown optical signal are specified.

Abstract: A test system comprising: providing a conditioning circuit; cabling a cable modem termination system to the conditioning circuit; signaling an initial ranging request to the cable modem termination system; and determining a transmission power limiter by the conditioning circuit monitoring a network for detecting a cable modem termination system response to the initial ranging request.

Abstract: A test system comprising: acquiring an upstream channel descriptor list; entering a pause network state when the upstream channel descriptor list is completed; and selecting a particular channel from the upstream channel descriptor list before exiting the pause network state.

Abstract: A remote test unit and method of operation are provided for utilizes the ability of an access matrix ability to route signals. The Remote Test Unit can emulate a central Digital Subscriber Line Modem (DSLM-C) for testing customer premises equipment containing a remote Digital Subscriber Line Modem (remote Digital Subscriber Line Modem). The Remote Test Unit can also emulate a remote Digital Subscriber Line Modem for testing central offices equipment including a digital subscriber line access multiplexer (DSLAM) containing a central Digital Subscriber Line Modem. The Remote Test Unit can also emulate a concentrator connected to the DSLAM, a router connected to the concentrator, an Internet service provider (ISP) connected to the router, and a web site connected to the Internet service provider over the Internet.

Abstract: A wireless network profiling system is provided including providing a base station tester for attaching to a cellular base station, using a global positioning system for logging the position information of the cellular base station, using the base station tester for collecting a parametric information from the cellular base station and using a mobile handset emulator for transferring the parametric information and position information for analysis and storage.

Abstract: A system for testing a portion of a cable network provides a pattern generator, Addresser, forward error corrector, and comparator. The system is particularly adapted to testing the upstream channel in a cable network. The pattern generator generates a test signal. The addresser addresses the signal to a known server and also instructs the known server to return the test signal to the test system. The forward error corrector corrects errors introduced in the test signal in transmission from the known server to the test system. The comparator then compares the returned test signal to the originally transmitted test signal to determine the performance of the back channel. Preferably, the comparator uses a bit error rate test to determine the performance of the back channel.

Abstract: A display system including: providing a processor; enabling a touch screen, having a measurement grid, by the processor; pressing a hard key, a soft key, a function tab, a function soft key, the measurement grid, or a combination thereof for activating the touch screen; and displaying a user data on the measurement grid of the touch screen by the processor.

Abstract: A system and method for testing a portion of a cable network provides a pattern generator, addresser, forward error corrector, and comparator. The system and method is particularly adapted to testing the upstream channel in a cable network. The pattern generator generates a test signal. The addresser addresses the signal to a known server and also instructs the known server to return the test signal to the test system. The forward error corrector corrects errors introduced in the test signal in transmission from the known server to the test system. The comparator then compares the returned test signal to the originally transmitted test signal to determine the performance of the back channel. Preferably, the comparator uses a bit error rate test to determine the performance of the back channel.

Abstract: An optical signal measurement system provides a tunable optical filter. An unknown optical signal is scanned through the tunable optical filter. The wavelength and chromatic dispersion values of the unknown optical signal scanned through the tunable optical filter are measured by operating the tunable optical filter in a scanning mode for at least one of OSA and PMD measurements, and in a stepping mode for CD measurements. The wavelength and the dispersion values in the unknown optical signal are specified.

Abstract: A network test architecture includes a plurality of modules for performing a plurality of functions, each of the plurality of modules having a unique identifier. An additional module for performing an additional function has an additional unique identifier. A control bus is connected among the plurality of modules; a data bus is connected among the plurality of modules; and a power bus is connected among the plurality of modules. A controller controls operation, data transmission, and powering of the plurality of modules and the additional module, respectively, through the control bus, the data bus, and the power bus, the controller using the unique identifier and the additional unique identifier of the plurality of modules upon simultaneous connection of the control bus, the data bus, and the power bus to the additional module.

Abstract: A method and apparatus for filter spectrum deconvolution and reshaping include providing a filter output of a spectrum signal and determining the intensity and wavelength of the spectrum signal at each spectral peak. The filter output is characterized as an integral of convolution of a spectrum signal function and a filter function. Transformation are then performed on the filter output to deconvolve and remove the undesirable filter function and add a desirable filter function to reshape the output filter spectrum.

Abstract: A method and apparatus for testing network data signals in an optical wavelength division multiplexing network employ an optical wavelength division multiplexing function and a network analysis function to analyze the optical spectrum and extract from and insert data signals into a wavelength division multiplexing network for data signal analysis by the network analysis function.