Abstract: A method for measuring the damping factor of an Nth-order phase-locked loop, wherein N>1, and a system, apparatus, and program that operate in accordance with the method. The method includes applying a modulation source at an input to the phase-locked loop. The method also includes measuring the output response to various levels of frequency modulation, measuring the ?3 dB cutoff frequency of the phase-locked loop, and measuring the peak frequency of the phase-locked loop. The method further includes calculating the damping factor of the phase-locked loop as a function of the ?3 dB cutoff frequency and the peak frequency.

Abstract: A method of providing dispersion compensation includes providing a dispersion signal indicative of an amount of dispersion for at least one channel of a multi-channel optical signal. A dispersion compensator is controlled in accordance with the dispersion signal to optically compensate for the dispersion of the optical signal.

Abstract: An echo canceller circuit is set forth. The echo canceller circuit includes a digital filter having adaptive tap coefficients to simulate an echo response occurring during a call. The adaptive tap coefficients are updated during the call using a Means Squares process. A tap energy detector is also employed. The tap energy detector identifies and divides groups of taps having high energy from groups of taps having low energy. The high energy tap groups are smaller in number than the low energy tap groups. The high energy tap groups are adapted separately from the low energy tap groups using the Least Squares process. Still further, the high energy tap groups may be adapted using an adaptive gain constant ? while the low energy tap groups are adapted using an adaptive gain constant ??, wherein ?>??.

Abstract: A method for cross connecting optical signals includes using a common beam steerer to direct a set of optical signals from a set of input ports to a set of output ports. The method further includes adjusting a curvature of the common beam steerer so that paths of the optical signals have substantially the same effective path length.

Abstract: A method for switching multi-rate communications is described. The method includes filling a first set of p timeslots with p sets of data from a first data collection of a first type, where the first data collection includes m sets of data and p is less than m. The method also includes loading at least one overflow timeslot with at least one overflow set of data from the first data collection, where the overflow set of data exceeds a size of the first set of p timeslots.

Abstract: A method of controlling behavior of an element in a passive optical network (PON) is provided. The method includes (i) issuing a message from a first PON element to a second PON element to cause the second PON element to enter or maintain a state of upstream communications, the state of upstream communications having an enabled state or a disabled state, (ii) ranging the second PON element by the first PON element if the state of upstream communications of the second PON element is in the enabled state, and (iii) bypassing the ranging of the second PON element if the state of upstream communications of the second PON element is in the disabled state.

Abstract: A method of managing a signal over a symbol period includes supplying samples of the signal at beginning and end portions of the symbol period. The method further includes suppressing the supply of samples of the signal at a middle portion of the symbol period.

Abstract: A multi-point communications system is set forth herein. The communications system comprises a transmitter for transmitting OFDM/DMT symbols over a predetermined number of bins across a transmission medium. The OFDM/DMT symbols are generated using at least one timing signal. At least one of the predetermined number of bins includes a pilot tone sub-symbol having a frequency corresponding to the clock signal. The communications system also includes a receiver for receiving the OFDM/DMT symbols from the transmission medium. The receiver demodulates the received symbols using at least one timing signal. The receiver has a first pilot tone search mode of operation in which the receiver adjusts its timing signal to scan the frequency range of the predetermined number of bins looking for the pilot tone sub-symbol and identifies the bin including the pilot tone sub-symbol.

Abstract: A communication system includes a first ingress content processor that receives information associated with a first traffic type. The first ingress content processor places the information associated with the first traffic type into a system cell having a common system cell format. A second ingress content processor receives information associated with a second traffic type. The second ingress content processor places the information associated with the second traffic type into a system cell having the common system cell format. A switch fabric receives system cells from the first and second ingress content processors. System cells from the first ingress content processor are automatically sent to the switch fabric while system cells from the second ingress content processor are required to be scheduled before being sent to the switch fabric.

Abstract: Methods and apparatus for managing an optical network using pilot tones are provided. One method includes selecting an optical path having a plurality of nodes from a database defining an expected optical network. A detected list of pilot tones associated with each node of the selected optical path is generated. An expected list of pilot tones associated with each node of the selected optical path is generated. The detected and expected lists are compared to identify any mismatched nodes.

Abstract: A wavelength division multiplexed optical communication system including a first optical line interface optically coupled to a first transponder and an optical demultiplexer through which the first optical line interface is not optically coupled to the first transponder. The system also includes a second optical line interface and at least one switch. The switch is operable to optically couple the second optical line interface to (a) the first optical line interface through at least the optical demultiplexer, and alternatively (b) the second transponder. A method for an optical add/drop multiplexing system also is provided.

Abstract: Interruptions between a source in a first network and a destination in a second network are reduced by providing first primary and secondary nodes in the first network, and second primary and secondary nodes in the second network. First primary routes in the first network facilitate delivery of a first set of the data to the first primary node; and a second set of the data to the first secondary node. Inter-network routes between the first and second networks deliver the first and second sets of the data to the second primary node and the second secondary node. Second primary routes in the second network facilitate delivery of at least one of the first and second sets of data to the destination. A selector within the second network selects one of the sets of data. Route selectors select secondary routes in the event that a primary route is disabled.

Abstract: An apparatus and method for suppressing noise is presented. The apparatus may utilize a filter bank of bandpass filters to split the input noisy speech-containing signal into separate frequency bands. To determine whether the input signal contains speech, DTMF tones or silence, a joint voice activity & DTMF activity detector (JVADAD) may be used. The overall average noise-to-signal ratio (NSR) of the input signal is estimated in the overall NSR estimator, which estimates the average noisy signal power in the input signal during speech activity and the average noise power during silence. Two indirect power measures are performed for each band, measuring a short-term power and a long-term power. The power estimation processes are adapted based on the signal activity indicated by the JVADAD. A NSR adapter adapts the NSR for each frequency band based on the long-term and short-term power measures, the overall NSR and the signal activity indicated by the JVADAD. The NSR adaptation may then be performed.

Abstract: Recovery time upon the failure of a link or switching system in an asynchronous data network can be minimized if downstream data switches provide upstream messages indicating to upstream switching system that the downstream traffic arrived in tact and was properly handled. Upon this loss or failure of the upstream status message to an upstream switching system, an upstream switching system can reroute data traffic around a failed link or failed switch with a minimal amount of lost data. The upstream status message is conveyed from a downstream switching system to an upstream switching system via a reverse notification tree data pathway.

Abstract: A communication system (10) receives a communication signal comprising first and second data with different compression levels, such as highly compressed and weakly compressed levels. A mode detector (15) detects the level of compression. One or more signal decoders (20, 22) decode the highly compressed data. An analyzer (30) determines the type of enhancement required. One or more processors (48, 50, 80) enhance the data as required. An encoder (60) reencodes the enhanced decoded data. Metrics (90) may aid the operation of the analyzer (30). The communication system may include telephones (120, 122, 124, 126). Processors (103, 104) enhance signals in opposite first and second directions between pairs of the telephones. A path (106) connects the processors in tandem. One or more switches (101, 102) disable signal enhancement for one of the processors depending on the compression level of the signals to avoid degrading call quality.

Abstract: A method and apparatus for reducing the complexity of linear prediction analysis-by synthesis (LPAS) speech coders. The speech coder includes a multi-tap pitch predictor having various parameters and utilizing an adaptive codebook subdivided into at least a first vector codebook and a second vector codebook. The pitch predictor removes certain redundancies in a subject speech signal and vector quantizes the pitch predictor parameters.

Abstract: The present invention provides for a method for reserving spare bandwidth for a link in a communication network including a plurality of links. The method provides for monitoring the volume of traffic routed through each link of the communication network. A single link failure for each link is then simulated and one volume of traffic which would be rerouted through each link for maintaining communication and the volume of traffic removed from each link are determined for each simulated single link failure. The difference between the volume of traffic which would need to be rerouted through each link and the corresponding volume of traffic removed from each link is then computed, and a maximum difference value is determined for each link for all simulated single link failures. An amount of spare bandwidth equivalent to the determined maximum difference is then reserved for each link.

Abstract: A communication system (10) employs switching circuits, such as an add/drop multiplexer (70) and another add/drop multiplexer (110). The bandwidth of a circuit switched connection between the switching circuits is altered without taking down the connection.

Abstract: Each node of a telecommunications network determines a connection type attributes available for each signal type supported by the node. Each signal type represents a different connection routing layer within the telecommunications network. Adaptation costs involved in traversing from one connection routing layer to another connection routing layer in the node are calculated. The connection type attributes and adaptation costs are included in a link state advertisement broadcasted by each node in the telecommunications network. A route calculation is performed for a desired signal to determine a route through the telecommunications network for the signal. The route calculation takes into account the various connection type attributes, availability, and adaptation costs in determining the shortest route for the signal through the telecommunications network.

Abstract: The apparatus, system, and method facilitates the replacement of software components. New versions of software components and files may be transmitted to a computer system for purposes of updating the existing software components and files on that computer system. Automatic updating systems, as are currently known in the art, may however, create problems in the receiving computer system if the transmitted software components or files are corrupt or are incompatible with the software already installed on the receiving computer. The apparatus includes a data construct that, when appended to a software component or file for transmission through a communications network, facilitates the detection of transmission errors and of system incompatibilities. This construct (trailer) includes compatibility tags for use with a rule engine or other apparatus to guarantee a software component's ability to coexist with other components within the receiving computer system.