Abstract: A method and apparatus for interference suppression in wireless communication systems, especially Orthogonal Frequency Division Multiplexed (OFDM) systems. The array apparatus includes a two-tier adaptive array system which provides for both spatial diversity and beamforming at the uplink. The adaptive array is comprised of sub-arrays spaced at a distance sufficient to provide spatial diversity, ideally 5 to 15 wavelengths at the frequency of operation. Each sub-array is composed of at least two antenna elements spaced in proximity sufficient to provide effective beamforming or scanning, ideally less then one-half of one wavelength at the frequency of operation. The Direction of Arrival (DOA) of signals impinging upon the array can be calculated by comparing signals from sub-array elements.

Abstract: Example embodiments of the present invention relate to increasing an aggregate capacity of a network without using a centralized switch fabric. A method and corresponding apparatus in an example embodiment of the present invention relates to increasing overall aggregate capacity of a switching system. The example embodiment includes a first switching shelf having a first predetermined aggregate capacity, and multiple second switching shelves having a second predetermined aggregate capacity. The second predetermined aggregate capacity is less than the first predetermined aggregate capacity. The example embodiment increases the overall aggregate capacity as a function of connections between the first switching shelf and the multiple second switching shelves. The shelves are interconnected with interconnection links and can be configured to connect to additional shelves as the switching system grows to larger sizes. Embodiments can increase capacity while reducing cost within a network node.

Abstract: A method of optical communication includes generating an amplified optical signal from at least a portion of a first optical signal having a first carrier wavelength, ?1. The amplified optical signal is applied to Brillouin media to stimulate generation of a Brillouin effect signal at a wavelength ?2. The Brillouin effect signal is modulated to produce a second optical signal having a second carrier wavelength, ?2. In one embodiment, the first optical signal is a downstream optical signal and the second optical signal is an upstream optical signal of a passive optical network.

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 the 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: To increase channel capacity, mobile phone carriers have deployed speech coders, such as Advanced MultiBand Excitation coding (AMBE), in networks to reduce the bit rate of each call. One undesired consequence of employing such speech coders is that the voice quality can be much worse as compared to higher bit-rate speech coders. A method or corresponding apparatus in an example embodiment of the present invention performs voice quality enhancement transparently within a network by detecting use of a coder applying rate reduction to a speech signal and known to have an adverse effect on a coded speech signal. Upon detection of the use of such coder, the coded speech signal is corrected based on components introduced into the coded speech signal due to the rate reduction. As a result of applying the voice quality enhancement, adverse effects of speech coders can be reduced, while maintaining high quality voice signals.

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: A method and corresponding apparatus for coded-domain acoustic echo control is presented. An echo control problem is considered as that of perceptually matching an echo signal to a reference signal. A perceptual similarity function that is based on the coded spectral parameters produced by the speech codec is defined. Since codecs introduce a significant degree of non-linearity into the echo signal, the similarity function is designed to be robust against such effects. The similarity function is incorporated into a coded-domain echo control system that also includes spectrally-matched noise injection for replacing echo frames with comfort noise. Using actual echoes recorded over a commercial mobile network, it is shown herein that the similarity function is robust against both codec non-linearities and additive noise. Experimental results further show that the echo-control is effective at suppressing echoes compared to a Normalized Least Mean Squared (NLMS)-based echo cancellation system.

Abstract: A system supports 50 ms protection switching times independent of network architecture. The system includes multiple protection switch fabrics to perform facility protection switching for the signals and a central switch fabric to switch a subset of the signals in a non-facility protection switching manner among the protection switch fabrics. Linear and ring network configurations are supported by the system. The system has flexibility to perform Linear Automatic Protection Switching (LAPS), Unidirection Path Switched Ring (UPSR) protection switching, and Bidirectional Line Switched Ring (BLSR) protection switching without burdening the central switch fabric with unnecessary or redundant traffic.

Abstract: Systems and methods are provided for managing process execution within an operating system. The systems and method store a process initialization file, preparing a process list of processes that can be controlled by an individual user, and monitoring execution of the processes based on the process list for each user. The process initialization file is managed by a user with a first level of access to the operating system, and indicates which processes may have process execution controlled by users of the system having a different second level of access to the operating system. A process list is prepared for each individual user having the second level of access.

Abstract: Having a fast method to perform impairment evaluation is useful for many networks. A method or corresponding apparatus according to an example embodiment of the present invention maintains a traffic engineering database of values representing characteristics of links in the network through storage of integer values representing advertised optical signal capabilities of links between the multiple optical nodes. The example embodiment determines a path through the network for optical wavelengths to be supported by the links represented in the database as a function of evaluating optical signal characteristics at each link along a possible path using the advertised optical signal capabilities and provides a selected path meeting an acceptable integrity of the optical wavelengths to a path establishment module to establish the path through the optical network. Example embodiments significantly reduce computational complexity associated with impairment evaluation and path selection in an optical network.

Abstract: A method for managing transport node capability information includes discovering a link end of a local transport node, modelling the local transport node's capability information as a first set of information structures, discovering a neighbor transport node, establishing a control adjacency link between control elements of the local transport node and neighbor transport node, modelling the neighbor transport node's capability information as a second set of information structures, exchanging the first and second sets of information structures between the control elements and identifying potential network layer links between the local and neighbor transport nodes, based on correlations in the first and second sets of information structures.

Abstract: A cost of a path may not be the only factor in searching for a path solution in a network. For example, some applications are delay sensitive and require finding a path that does not exceed a latency constraint for the entire path. Accordingly, a method and corresponding apparatus for searching for a path solution in a network is provided that identifies combinations of partial paths that satisfy an end-to-end path constraint, compares attributes of the combinations of partial paths, prunes the combinations of partial paths based on results of the comparing to identify candidate combinations of partial paths, and selects a candidate combination of partial paths as the path solution. By pruning combinations of partial paths, considerable is saved compared to exhaustive comparing of every possible combination of partial paths and scalability is achieved.

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: An all-optical cross-connect switching system provides optical switching that may reduce processing requirements by three orders of magnitude over conventional techniques by associating at least one optical detector with an optical beam steering element. In one embodiment, a first beam steering element, having a reflective surface in optical association with a first optical fiber array, and a second beam steering element, having a reflective surface in optical association with a second optical fiber array, are optically arranged to direct an optical beam from a first optical fiber in the first optical fiber array to a second optical fiber in the second optical fiber array. The optical detector provides information about a first position of the optical beam on the second beam steering element. Based on this information, the angle of the first beam steering element may be adjusted to cause the optical beam to change to a second position on the second beam steering element.

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 method, apparatus, and program, for evaluating an optical network node. The method comprises providing at least one communication path of the node with a capability by which lasing can occur in the communication path, and detecting whether lasing has been established in the communication path to determine whether the optical node is operational. If no lasing is detected in the detecting, a fault exists in the communication path. The method further comprises determining an insertion loss in the communication path, and determining whether the insertion loss is comparable to a predetermined insertion loss, to confirm whether the node is configured correctly.

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: An apparatus for replacing lost PSTN data in a packet network and for generating variable power white noise, includes a lost packet detection unit (402) for detecting lost data packets, a data processing unit (404) for producing in response a lost data output indicating when replacement data needed, data playout unit (408) or data replacement unit (406), each may be implemented as a variable power white noise generator (FIG. 3) to generate replacement data by reusing data stored in an extended playback buffer, and placing the re-used replacement data on an external network.

Abstract: To perform protection switching between tunnels in a network, Y.1731-based APS messages are often sent from a management system to nodes at the tunnels' end-points. If the management system is located near one node (local node) and far away from the other node (remote node), the APS message, which operates at the Ethernet service layer, travels to the remote node slower than traffic over the tunnels. This slower transmission time may prevent the remote node from performing a switch within a desired timeframe. The disclosed embodiments include a 1:1 bidirectional VLAN-based protection arrangement that accomplishes a 50 millisecond switching time without using Y.1731-based APS messages. The embodiments accomplish this by sending a switching command from the management system to the local node and modifying a message already traveling from the local node to the remote node to include a switching message that causes the remote node to perform the switch.

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.