Abstract: A method of performing cell delineation in a communications network is described. The method includes providing a data cell defined based on a communications protocol. The data cell forms at least a portion of a data stream. The method further includes mapping the data cell into frames defined based on a network protocol, where adjacent frames are separated by a frame boundary. The data cell and frames have a common fundamental base structure represented by a data unit The data cell includes a boundary data unit defining a cell boundary The boundary data unit includes validation information for an associated segment of data units in the data cell. The method also includes analyzing a set of the data units independent of the frame boundary to determine potential validation information. The method includes comparing the potential validation information with content of at least one of the data units to identify the boundary data unit and the frame boundary.

Abstract: In order to enhance the quality of a communication signal derived from speech and noise, a filter divides the communication signal into a plurality of frequency band signals. A calculator generates a plurality of power band signals each having a power band value and corresponding to one of the frequency band signals. The power band values are based on estimating, over a time period, the power of one of the frequency band signals. The time period is different for different ones of the frequency band signals. The power band values are used to calculate weighting factors which are used to alter the frequency band signals that are combined to generate an improved communication signal.

Abstract: Packets used for distributing timing information over a Resilient Packet Ring (RPR) are generated by encoding Synchronization Status Messaging (SSM) messages into IEEE 802.3ah OAM packets (or any other OAM packets, such as those defined in ITU Y.1731). Information indicating the direction that each message is to be transmitted around the RPR ring is also encoded in the packets in either the spare bits of the SSM messages or in the Type-Length-Value (TLV) bytes of the IEEE 802.3ah OAM packets or Y.1731 OAM packets. RPR protection is disabled for the packets carrying the SSM messages and the packets are transmitted to adjacent network nodes in the directions specified by the information encoded in the messages. Information encoded in received packets specifying timing quality and direction of the received messages is observed and compared to determine which timing information included in the messages to use for clock timing.

Abstract: A system and associated method for the synchronization and control of multiplexed payloads over a telecommunications network wherein the asynchronous timing relationships between multiplexed payloads having varied points of origin are retained subsequent to signal processing of the payloads for further transmission to a destination point. System modules 22 include a network interface section 30, a synchronization, multiplexing and control (SMC) section 50, and a processing section 110. The SMC section 50 includes network interface bus circuitry, payload segmentation and re-assembly circuitry, control and management memory and related circuitry, payload re-assembly circuitry, and processor bus interface circuitry. The processing section of module 22 provides means for data compression, echo cancellation, error correction coding, or voice and data encryption/decryption. The module 22 is dynamically configured through a software management and control interface.

Abstract: A method and corresponding apparatus allows unknown packet traffic, such as Ethernet traffic, to be carried on a Resilient Packet Ring (RPR) network without flooding the traffic on the RPR network. Modules in a station of the ring network compare a destination address in a packet traffic signal with known addresses and associate an identifier of a tunnel in the ring network with the packet traffic signal based on the comparison. The modules then associate with the packet traffic signal an identifier of a destination station in the ring network that corresponds to the identifier of the tunnel and forward the packet traffic signal to the destination station via the tunnel. By transmitting the packet traffic via tunnels instead of flooding the RPR network, spatial reuse may be implemented allowing the network to support a higher volume of traffic.

Abstract: A method to provision routes in a network having a plurality of nodes includes receiving a designation of a primary source node, determining possible destination nodes from the designated source node and outputting information indicating the possible destination nodes. The method further includes receiving a designation of a destination node from among the possible destination nodes and updating information regarding optical characteristics based on a route from the source node to the designated destination node and outputting information related to the updated optical characteristics.

Abstract: A multi-point communications system is set forth herein. The communications system comprises a head end unit disposed at a primary site and a plurality of receivers disposed at remote sites. The head end unit includes a transmitter for transmitting OFDM/DMT symbols over a predetermined number of bins across a transmission medium. The OFDM/DMT symbols are transmitted in periodically occurring formatted symbol frames. The cyclic prefix includes a predetermined periodic signal superimposed thereon. The receivers receive the OFDM/DMT symbols over a subset of the predetermined number of bins from the transmission medium and use the superimposed signals to attain symbol alignment. Preferably, the superimposed signal is an impulse signal that varies in polarity throughout the transmission cycle and which is superimposed on one or more symbols occurring during a cyclic prefix of the formatted symbol frames.

Abstract: Methods and apparatus to extend the bandwidth of a speech communication to yield a perceived higher quality speech communication for an enhanced user experience. In one aspect of the invention, for example, methods and apparatus can be used to extend the bandwidth of a speech communication beyond a band-limited region defined by the lowest limit and highest limit of the frequency spectrum by which such speech communication is otherwise characterized absent such bandwidth extension. In another aspect of the invention, for example, methods and apparatus can be used to substitute for corrupt, missing or lost components of a given speech communication, or to otherwise enhance the perceived quality of a speech communication, by extending the speech communication to include one or more artificially created points within the region defined by the lowest limit and highest limit of the frequency spectrum by which such speech communication is characterized.

Abstract: A method to provision routes in a network having a plurality of nodes and a plurality of links connecting various nodes. The method includes determining a route between a designated source node and a designated destination node based on a preselected routing algorithm and one of (i) a designated node of interest and (ii) a designated link of interest, and outputting information indicating the determined route.

Abstract: Network applications rely on ever-increasing diverse and complex transport service mechanisms. A transport service between points in a network often traverses multiple technologies involving numerous containments and adaptations. A network event affecting the transport service may occur in any number of elements supporting the transport service, resulting in a myriad of alarms. Prior techniques for suppressing alarms involving complex network information models and coding logic to reduce the number of alarms presented, but require additional steps before the network event can be troubleshot and resolved. In contrast, the provided alarm correlation technique presents a highly structured and comprehensive visual presentation depicting the network event affecting the transport service in terms of the supporting elements affected by the network event.

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 non-linear processor for use in an echo canceller is set forth. The non-linear processor includes a center clipping digital filter receiving an echo compensated signal. The non-linear processor provides a center clipped output signal having non-linear thresholds at values of +TNLP and ?TNLP. The value of TNLP is dynamically dependent, at least in part, on echo return loss measurements. To limit the processor's susceptibility to corruption from double-talk conditions, the non-linear processor inhibits the dynamic setting of the TNLP value when a double-talk condition is present. Additionally, or in the alternative, the non-linear processor locks the value of the echo return loss measurement after a predetermined number of consecutive echo return loss measurements have values falling within a predetermined range of one another. Such locking further reduces the susceptibility of the non-linear processor to corruption from double-talk conditions.

Abstract: An echo canceller circuit for use in an echo canceller system is set forth that provides sensitive non-linear echo path response detection. The echo canceller circuit comprises a first digital filter having non-adaptive tap coefficients to simulate an echo response occurring during a call. A second digital filter having adaptive tap coefficients to simulate an echo response occurring during the call is also used. The adaptive tap coefficients of the second digital filter are updated over the duration of the call. A coefficient transfer controller is disposed in the echo canceller circuit to transfer the adaptive tap coefficients of the second digital filter to replace the tap coefficients of the first digital filter when a set of one or more transfer conditions is met. A non-linear echo path response detector is provided. The non-linear echo path detector is responsive to one or more parameters of the first and second digital filters to detect a non-linear echo path condition.

Abstract: An interconnect element incorporates a plurality of smaller, substantially identical, interconnect modules. Multiple identical elements can in turn be combined to form larger interconnect networks. Signal paths in the elements can be implemented with optical fibers or electrical conductors.

Abstract: A multiple carrier communication system includes a primary impulse shortening filter that receives an output signal of an analog to digital converter and accepts coefficients. A secondary impulse shortening filter receives the output signal of the analog to digital converter, outputs an output signal, and passes coefficients to the primary impulse shortening filter. A reference signal generator outputs a reference signal. A comparator compares the output signal and the reference signal and outputs a resulting error signal. An adaptive processor computes coefficients for the secondary impulse shortening filter based on the error signal.

Abstract: A cable management system is provided that is configured to be located between adjacent equipment racks, while being vertically oriented to extend upward along a narrow space between the adjacent equipment racks. The cable management system comprises a main panel extending along a vertical longitudinal axis, the main panel having a series of module cutouts provided therein and oriented to extend along the longitudinal axis. The system further includes inter-bay functional modules secured in at least two of the module cutouts. The inter-bay functional modules include at least two of a fiber spool module, a patch panel module and a dispersion compensation module. The main panel includes a front wall having the module cutouts formed therein. The front wall is integrally joined with side flanges extending rearward therefrom to form a channel cross-section.

Abstract: A reduced-complexity, fast converging adaptive filter may be used for network echo cancellation applications, including applications having sparse echo paths. The new filter, referred to as a selective-partial-update proportionate NLMS filter, may be based on a proportionate NLMS (PNLMS) technique and selective partial updating of the adaptive filter coefficients. The new PNLMS filter may exploit sparseness of a communications channel to speed up the initial convergence of the NLMS technique included in the filter by weighting regressor data proportionately with an estimated magnitude of the channel impulse response. Selective partial updating is essentially a data selection method to reduce the computational complexity. The performance of the selective-partial-update PNLMS filter compares favorably to an adaptive filter using standard PNLMS for echo paths specified in ITU-T Recommendation G.168.

Abstract: A channel in a multiple carrier communication system is equalized by computing a target spectral response, shortening the impulse response of the channel so that a significant part of an energy of the impulse response is confined to a region that is shorter than a target length and filtering the signal based on the target spectral response.

Abstract: In order to enhance the quality of a communication signal derived from speech and noise, a filter divides the communication signal into a plurality of frequency band signals. A calculator generates a plurality of power band signals each having a power band value and corresponding to one of the frequency band signals. The power band values are based on estimating, over a time period, the power of one of the frequency band signals. The time period is different for different ones of the frequency band signals. The power band values are used to calculate weighting factors which are used to alter the frequency band signals that are combined to generate an improved communication signal.

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.