Abstract: In a method and apparatus for measuring and controlling signal gain of a backward Raman amplifier having multiple pump lasers as used in optical communications networks, Raman pump power levels required to provide a uniform gain across a range of wavelengths in an optical fiber are determined by a combination of theoretical calculations and empirical measurement. A system of non-linear differential equations is solved for various pump powers and used to build a look-up table relating desired average Raman gain to the normalized power required to provide a uniform gain across a range of wavelengths. The linear relationship between Raman pump power and average Raman gain is determined by measuring data signal power levels at specific Raman pump powers. A desired average Raman gain is first applied to the linear relationship to determine total power required, and then applied to the look-up table to determine the required relative pump powers.

Abstract: A method and apparatus for transmit power control in a subscriber loop for high frequency data services are described. Transmit signal power levels are maintained at minimum levels for achieving acceptable communications between a transmitter and a receiver. Transmit signal power levels are adjusted dynamically on a link-by-link basis by employing command controllable transmit power attenuators at the transmitters. The transmit power attenuators are controlled by transmit signal power controllers which issue commands to the transmit power attenuators. Excess transmit power is avoided and parasitic signal coupling between communication links is reduced. The advantages are cross-talk reduction, longer loop length and higher data rates.

Abstract: A method and system adapted to receive electronic text messages and generate connection request messages used to establish toll call connections. The system includes a call control database, customer profile database, billing database, call control node, and point of presence switch that interfaces with the PSTN. The electronic text messages are received through the Internet and may be electronic mail, short message service, or instant text messages.

Abstract: A design analysis workstation for performing design analysis of integrated circuits provides facilities for extracting design and layout information from digital image-mosaics captured during deconstruction of an integrated circuit. Each image-mosaic is displayed in at least one mosaic-view as a background image that is overlaid with at least one annotation overlay. An engineer analyst creates annotation objects on the annotation overlay based on information inferred concurrently from one or more image-mosaics. Concurrent display of a plurality of image-mosaics facilitates the understanding of interrelations between components on different layers. The design analysis workstation displays a plurality of cursors in respective views of mosaic-images, the cursors having lock-step motion to facilitate comprehension of the alignment of features on different concurrently displayed image-mosaics.

Abstract: An apparatus and method for maintaining access to lifeline services through telephone sets provided with telephone service from a voice over digital subscriber loop (VoDSL) transceiver during power interruptions are described. All telephone sets associated with the transceiver are connected to a wire loop which supports the VoDSL service in the event of a power interruption to the transceiver. The advantage is the economical provision of lifeline service access to all telephone sets when power is interrupted to the transceiver. Thus, confusion is reduced, safety is enhanced, and access to lifeline services is ensured during emergency situations.

Abstract: Methods of caching tile image constituents of image-mosaics enable a substantially smooth real-time display of portions of the image-mosaic in a view during panning, resizing, or zooming of the view. The method includes using a predictive algorithm to identify tile images to be retrieved from a remote store through a local area network, and for sequencing requests for the retrieval of tile images from the remote store. A scheduler calculates time spent in retrieving and servicing each tile image retrieval request and proportionately pauses retrieval of tile images after each request is serviced in order to prevent over utilizing LAN resources. The advantages are that tile images to be displayed are cached in accordance with a priority to facilitate image display while network data transfers are distributed in time.

Abstract: Methods and apparatus are provided for processing messages for access to information stored in an open directory. A Lightweight Directory Access Protocol (LDAP) LDAP Validation Proxy (LVP) is used to intercept LDAP request messages intended for the directory, validates the LDAP requests according to a schema description and optionally provides side-effects. The schema validation and LDAP message processing is modularized according to object classes representing the data stored in the directory and according to services provided. The schema is enforced by validating LDAP messages. This modularization provides a controlled message processing granularity and enables multi-threaded concurrent processing of multiple LDAP messages. The LVP has the capability of generating LDAP requests in processing LDAP messages. The LVP also intercepts and processes LDAP responses issued by a directory and intended for clients.

Abstract: An algorithm for media access control over nodes in a buffer insertion ring is described. Each node computes a local add rate and an advertised rate which it communicates to its upstream link partner node. The rate calculations are based on a locally computed tandem rate and a downstream rate received from a downstream link partner node. The algorithm ensures rapid convergence to a fair add rate at which nodes share link resources to avoid starvation in the ring. The advantages include short head of line delay, low operating overhead, and good bandwidth utilization.

Abstract: A method and apparatus for transporting IP datagrams over SONET at a guaranteed quality of service are described. The method utilizes a multi-level bandwidth management hierarchy. A bandwidth allocation manager provides real time high level control of bandwidth allocation in each SONET domain. A bandwidth client at each node in the domain negotiates bandwidth requirements for IP services connected to the node. This enables low error bit rate, scalability and reliable service that can provide guaranteed quality of service for IP applications. All aspects of connection setup, bandwidth allocation, bandwidth size adjustment and connection termination are negotiated by the bandwidth client with the bandwidth allocation manager. Multiple domains can be interconnected to form larger networks providing reliable connections at a guaranteed QOS.

Abstract: A system and method for stereoscopic video teleconferencing provides an immersive virtual meeting experience. Each participant is surrounded by at least two video cameras. The system senses the position of each of the participants and uses this information to select, for each participant, camera pairs to capture a stereo pair of video images of each of the other participants. The system is adapted to isolate the image of each participant from the background. The system transforms the stereo pair images to adjust the perspective for the interocular spacing of each participant. The processed stereo pairs of video images are transmitted to the respective participants. For each participant, the system assembles a stereo video display image of a virtual meeting room, combining the stereo pair images of each of the other participants appropriately sized and positioned. Three-dimensional (3D) virtual objects can also be displayed and manipulated by participants.

Abstract: A method and a network for a universal transfer mode (UTM) of transferring data packets at a regulated bit rate are disclosed. The method defines a protocol that uses an adaptive packet header to simplify packet routing and increase transfer speed. The protocol supports a plurality of data formats, such as PCM voice data, IP packets, ATM cells, frame relay and the like. The network preferably includes a plurality of modules that provide interfaces to various data sources. The modules are interconnected by an optic core with adequate inter-module links with preferably no more than two hops being required between any origination/destination pair of modules. The adaptive packet header is used for both signaling and payload transfer. The header is parsed using an algorithm to determine its function. Rate regulation is accomplished using each module control element and egress port controllers to regulate packet transfer.

Abstract: A pulse width modulation control circuit for a high frequency series resonant AC/DC converter suitable for use in computing and network equipment such as personal computers, servers and high-speed routers includes an auxiliary transformer, a zero crossing detector, a delay circuit, a synchronization circuit and an output circuit.

Abstract: A self-configuring distributed switch is disclosed. The switch comprises a channel switch core connected by a plurality of channels to a plurality of high-capacity data switch modules. A global controller selects paths through the channel switch core and reconfigures the paths in response to dynamic changes in data traffic loads. Propagation delays between the data switch modules and the channel switch core are coordinated to keep reconfiguration guard time minimized. The advantage is a very high-capacity, load-adaptive, self-configuring switch that can be geographically distributed to serve a large geographical area.

Abstract: An apparatus for extracting design and layout information from image-mosaics of a progressive deconstruction of a semiconductor integrated circuit (IC) includes a visual display, a system pointer and a plurality of lockstep cursors. The visual display displays views of an area of interest of the respective image-mosaics. Each view displays one of the lock-step cursors when appropriate, as determined by a position of the system pointer. When the system pointer is within a view, a corresponding lock-step cursor is displayed as a master-cursor, while other views display a lock-step cursor that has a different size and shape than the master-cursor. All lock-step cursors move in unison under the control of the master-cursor. A method for extracting design and layout information from image-mosaics uses the lock-step cursors to quickly match features across image-mosaics, and to avoid transposition errors while tracing features from one image-mosaic to another.

Abstract: A method of address resolution for the transfer of voice and voice data calls through multiple domains in a broadband data network is described. The implementation of broadband data networks as transport backbones for voice and voice data calls requires address resolution to determine the destination node for each call. Because of the projected frequency at which new access peripherals will be added to such broadband data networks, manual maintenance of translation tables is impractical. The invention therefore provides an automated method for address resolution which permits voice interface control units associated with the broadband data network nodes to automatically maintain the required translation tables. Next-hop resolution routing tables may be maintained at every node or only at nodes designated as signaling gateways between broadband data network domains.

Abstract: A high-frequency resonant sine wave DC to AC inverter suitable for use in a personal computer (PC) power supply includes a full-bridge inverter, a resonant circuit, a phase shift modulation circuit, and a resonant gate driver. The resonant gate driver provides sinusoidal gate drive signals to the full-bridge inverter enabling highly efficient operation on the inverter.

Abstract: A method for use of IN-service Non-intrusive measuring Device (INMD) for proving Service Level Agreements (SLAs) and pro-active maintenance in IP telephony networks is described. The INMD is currently used only in connection oriented TDM telephony networks and therefore cannot be used directly in the connectionless-featured IP telephony networks. The method for use of INMD to measure voice transmission quality in IP telephony networks include a set of pre-processes for processing IP voice datagrams, and converting the pre-processed datagrams to a format suitable for INMD before the INMD evaluates data in the datagrams for voice GOS. Various tests and co-processes are also used to determine network performance parameters. An IP telephony measurement apparatus for practicing the method is also described. A method for calibrating the device and algorithms is also provided to ensure a high level of confidence in the measurement accuracy.

Abstract: A self-configuring distributed switch has agile core modules connected by a plurality of channels to a plurality of large capacity edge modules. A core module controller selects paths through an associated core module and reconfigures the paths in response to dynamic changes in data traffic loads. Switching latency in the core modules is masked so that the source edge modules need not disrupt data transmission during reconfiguration. Surplus capacity is provided in the core modules to facilitate reconfiguration. Connection release and connection setup policies increase occupancy variance among the space switches in each core module to further facilitate reconfiguration. The reconfiguration functions of the data switch modules and the core modules are coordinated to keep reconfiguration guard time minimized. The advantage is a high capacity, load-adaptive, self-configuring switch that can be geographically distributed to serve a large geographical area.

Abstract: A digital subscriber line framing structure supporting imbedded rate adaptive synchronous and asynchronous traffic. The frame includes a system for alternating a first payload group for the synchronous traffic with a second payload group for the asynchronous traffic in the payload portion of the frame. The size of at least one of the first and second payload groups can be modified for adapting to variations in demand for synchronous traffic over the digital subscriber line or for data rate variations over the subscriber line due to line quality variations.