Abstract: A fault warning system controls light sources and a warning signal to provide an indication of fatal and non-fatal faults in a communication system. The circuitry uses a pull-down circuit in electrical communication with light and signal control circuits. The circuit can be operated to activate a first light emitting diode (LED) if an operational status of a monitored circuit is either fatal or non-fatal fault. The circuit can be operated to deactivate a second LED if an operational status of a monitored circuit is fatal, and the second LED remains active if the operational status of the circuit is a non-fatal fault.

Abstract: A fan control system uses a closed loop system to adjust the actual operating speed of a fan or fans to a desired operating speed. The desired speed and actual speed are compared in a high gain amplifier to generate a control signal to adjust the actual operating speed of the fan given the feedback.

Abstract: A circuit card that includes a single ground plane connectable to a chassis-ground and a logic device having a ground pin connected to the single ground plane. The connection between the ground pin and the single ground plane provides a direct path between the logic device and the chassis-ground. A power supply is connected to an input pin of the logic device for providing a logic voltage to the logic device. The power supply is connectable to a battery.

Abstract: A integrated access device in a communication network. The integrated access device in one embodiment includes a network port, a plurality of telephony ports, a data port and communication circuit. The network port is adapted to provide dynamic time division multiplex (TDM) interface to a communication network. The plurality of telephony ports are adapted to provide telephony service to subscriber premises equipment. The data port is adapted to provide digital subscriber line (DSL) service to subscriber premises equipment. The communication circuit is coupled to the network port, the plurality of telephony ports and the data port. Moreover, the communication circuit is adapted to carry voice and data signals between the network port and the plurality of telephony ports and the data port. In addition, the integrated access device is line powered over the network port.

Abstract: A junction field effect transistor (JFET), acting as a switch, is coupled between the source and gate of a metal oxide semiconductor field effect transistor (MOSFET). A capacitor is connected in parallel with the MOSFET's “Miller capacitance” by being coupled between the gate and drain of the MOSFET in series with a current limiting resistor. When the JFET is on, it has a low impedance with zero gate voltage and forces the gate to source voltage of the MOSFET to remain near zero and, thus, the MOSFET in a high impedance state, until the capacitor charges to the supply voltage.

Abstract: An electronic module having a chassis and a single backplane disposed within the chassis. A plurality of bridge circuit cards is disposed within the chassis and is electrically connected to the single backplane. Each of the plurality of bridge circuit cards is for converting between a local area network protocol and a wide area network protocol. A hub circuit card is disposed within the chassis and is electrically connected to the single backplane so that the hub circuit card is electrically connected to each of the plurality of bridge circuit cards. The single backplane is connectable to each of a plurality of remote units for respectively electrically connecting each of the plurality of remote units to each of the plurality of bridge circuit cards. The single backplane is connectable to a data network for electrically connecting the data network to the hub circuit card.

Abstract: A central office line unit (COLU) for a pulse code modulation (PCM) upstream and downstream system in a universal digital loop carrier (UDLC) includes a hybrid circuit for transmitting/receiving an analog signal to/from a switch. An analog-to-digital converter is provided for receiving the analog signal from the hybrid circuit and converting the analog signal to a converted digital signal. A digital transmission circuit transmits/receives a digital signal to/from a remote terminal. A quantizer is provided for evaluating and processing the converted digital signal so that only valid states of the converted digital signal are transmitted to the digital transmission circuit for transmission to the remote terminal. A receiver is used for receiving the digital signal from the digital transmission circuit and for evaluating and processing the digital signal so that only valid states of the digital signal are outputted from the receiver.

Abstract: An electronics enclosure is provided. The enclosure includes a modular card cage adapted to receive one or more electronic circuit cards and a heat sink adapted to protrude through an opening of an enclosure and couple to the modular card cage. The modular card cage and the heat sink provide an isolated heat transfer path for heat, produced by each of the one or more electronic circuit cards, to be removed from the enclosure.

Abstract: A port isolator apparatus includes an optical isolator circuit that electrically isolates an input circuit from a high-speed output circuit. The input circuit uses a transistor to control the current flow of a data signal into the optical isolator. The optical isolator generates, from the data signal, an output signal that controls the high-speed output circuit in the regeneration of the output signal. The output signal is substantially similar to the input data signal. The input circuit and the optical isolator circuit are coupled to one power and ground circuit while the high-speed output circuit is coupled to a second power and ground circuit that is isolated from the first power and ground circuit.

Abstract: A system of terminating signals in a telecommunication system is disclosed. In one embodiment a line card comprises functional circuitry, line card connector contacts and a termination resistor. The functional circuitry is used to interface first type ports with second type ports. The line card connector contacts are adapted to be selectively coupled to a backplane of a chassis. The termination resistor is adapted to terminate signal lines when a jumper is coupled across select line card contacts.

Abstract: Apparatus and method for increasing the bandwidth of an optocoupler includes cascode coupling the optocoupler driver transistor with a buffer so as to reduce voltage variations across the driver transistor.

Abstract: A fault associated with a communication medium is analyzed by correlating a first set of information indicative of echo associated with the communication medium with a second set of information indicative of echo. The fault is characterized based on the correlation between the first set of information and the second set of information. The first set of information and the second set of information can include echo canceller coefficients generated by an echo canceller coupled to the communication medium.

Abstract: A fault associated with a communication medium is analyzed by correlating a first set of information indicative of echo associated with the communication medium with a second set of information indicative of echo. The fault is characterized based on the correlation between the first set of information and the second set of information. The first set of information and the second set of information can include echo canceller coefficients generated by an echo canceller coupled to the communication medium.

Abstract: A graphical user interface element such as a window or a screen is displayed on an output device by sending a single message indicating that the graphical user interface element should be displayed. The message is received, and all the components of the graphical user interface element are displayed. After that, the graphical user interface element can be updated on a component-by-component basis.

Abstract: A set of edits to data stored in a first database are stored in a second database before submission for rules checking and, if appropriate, storage in the first database. The set of edits are submitted for rules checking as a group.

Abstract: A first process communicates to a second process what data will be used to display a graphical user interface element such as a window or screen. The second process determines if the data used to display the graphical user interface element has changed, and, if the data used to display the graphical user interface element has changed, communicates to a third process that the data used to display the graphical user interface element has changed. Moreover, the third process receives the communication that the data used to display the graphical user interface element has changed, and, in response to the communication that the data used to display the graphical user interface element has changed, displays the graphical user interface element.

Abstract: A bit error rate or other performance characteristic of a communication link is monitored using a state machine. The state machine includes at least three states. A sliding window is used in two of the states to determine what state to transition to next. A sum is calculated as a function of the sliding window.

Abstract: A method for initiating an action based on a received signature in an input signal is provided. The method includes receiving elements of the input signal, determining when elements of the input signal match corresponding elements in the signature, and initiating a selected action when a selected subset of the elements of the signature match consecutive elements of the input signal.

Abstract: An output of a first data register is coupled to an input of a second data register. The same periodic clock signal clocks both data registers. A controller monitors the clock signal, a first load signal and a read signal. The controller generates a guard band signal using the clock signal and the first load signal. The controller also generates a second guard band signal from the read signal and the clock signal. A second load signal, that is used to load the second data register, is created by performing a logical AND operation on the two guard band signals.

Abstract: An apparatus and method is described that allows for improved correlation of multiple signatures from an input datastream, reducing the complexity and memory size of the correlation operation by utilization of a multiple sequence indexing correlator. The multiple sequence indexing correlator keeps an index into each signature that indicates how many elements have been matched so that only the remaining portion of each signature must be compared to the input data stream. Because of this, no history of the input datastream is kept and only a small portion of each signature is compared at one time. Additionally, the multiple sequence indexing correlator allows for ease of signature modification or addition, pre-execution of functions, signatures with identical substrings but differing lengths to be detected, wild card signature elements, timeouts to determine signature end, null functions, execution hold off for extended signatures, and keystroke detection.