Abstract: A flexible band tunable filter design is disclosed which is capable of selecting any single channel or multiple of adjacent channels in a waveband of an optical signal in an optical communication network. The flexible band tunable filter has particular application in wavelength division multiplexing communication networks.

Abstract: A flexible band tunable filter design is disclosed which is capable of selecting any single channel or multiple of adjacent channels in a waveband of an optical signal in an optical communication network. The flexible band tunable filter has particular application in wavelength division multiplexing communication networks.

Abstract: An overlay model to let multiple VPNs share the same physical switches while maintaining their individual resource and administrative boundaries. A clean resource and protocol management structure within the ATM switches is provided for the overlay model. An architectural framework for such resource and protocol management within multiprocessor ATM switches is provided. Multiple protocols are supported both at the switch level and at the port level. A VPN on a switch can be configured with any of the existing control protocols available on that switch. This protocol management mechanism is then extended for providing intra-VPN multiprotocol support where a single VPN is allowed to use multiple control protocols on the same switch port. A mechanism for Network Management System (NMS) coordinated VPN creation and configuration is provided.

Abstract: A scanner has an optical-electric module, an incoherent fiber bundle, and a scanner head. The incoherent fiber bundle has illumination fibers and pickup fibers. The illumination fibers carry only illumination light from a light source in the O/E module toward the scanner head. The pickup fibers carry sensed light from the scanner head to a CCD array in the O/E module. The scanner head has a light guide that receives the illumination light from the illumination fibers. The light guide is in contact with the pickup fibers in an arrangement which permits the illumination light to enter the side of the illumination fibers near the end. Illumination light reflected back into the pickup fibers is guided to the CCD array.

Abstract: The present invention pertains to message sets for use in a flexible programmable multiplexer for accessing an Asynchronous Transfer Mode (ATM) network. The access multiplexer uses a functional separation of line related functions and protocol related functions. Line interface cards perform line related functions. A message set for use in such a multiplexing system that uses a functional separation of line and protocol related functions is provided. The message set includes a general message, a hello message, a configuration message, a line stabilized message, an identify remote message, an identify remote acknowledgement message, a reset remote message, a report statistics message, a report statistics acknowledgement message, a loopback test message and a dynamic rate adaptation message. A flexible programmable multiplexer that uses the message set is also provided.

Abstract: A hand-held optical scanner for reading color images formed on a document. The scanner head is all-optical and contains no electronics. Optical fiber bundles couple the scanner head to a remote opto-electronic module containing a linear or a 2D sensor array for converting optical signals, reflected from the document, to electrical signals for transmission to a computer display, etc. By using side coupling, the transmitted and reflected light for each pixel travels through the same optical fiber without the need for a beam splitter. The optical fibers are used for the functions of image scanning, position encoding, and signaling a computer which assigns each one of incoherently arranged optical fibers to one of the functions.

Abstract: An optical fiber that controllably taps and distributes light propagating through an the optical fiber that comprises an optical fiber having multiple regions each having a different index of refraction from one another such that when light traverses the optical fiber along a length it travels from a region of one index of refraction to another region having a different index of refraction the light is sufficiently deflected such that it is distributed out a side of the optical fiber along its length. In a preferred embodiment, at point in the length of the fiber where a change in index of refraction occurs, light traversing the fiber is efficiently diverted out of the optical fiber through the side of the fiber. The light so diverted alternatively is refracted by one or more refractive regions, and alternatively focused by prism films applied to the exit side of the fiber where it may then be put to an advantageous use.

Abstract: In a multipoint communication system, first polling signals are sequentially and respectively transmitted to terminal stations on a broadcast channel from a central station, asking a request for reservation without waiting for a reply from the terminal stations. A reservation signal is transmitted on a multiple access channel from a terminal station requesting the reservation to the central station in response to the first polling signal addressed to it. A second polling signal is then transmitted on the broadcast channel in response to the reservation signal and the multiple access channel is reserved for a period of time variable in accordance with the reservation signal. A data signal is transmitted from the terminal station requesting the reservation on the reserved multiple access channel in response to the second polling signal.

Abstract: A quality measure of a signal received at a receiver of a two-dimensional linear modulation data communication system, is measured by using a phase controlled baseband signal (y.sub.k.exp(j.phi..sub.k)) obtained from the received signal and a reproduced data signal (x.sub.k) derived from the phase controlled baseband signal. That portion of the quality measure which is introduced into the received signal in a transmission channel for the received signal, is measured by estimating a data signal component (y.sub.k) which includes intercode interference, by subtracting the data signal component from the phase controlled baseband signal to produce a difference signal of a phase difference relative to the reproduced data signal, by giving the phase difference to the difference signal to produce a phase adjusted signal, and by calculating a mean square of an inphase component of the phase adjusted signal.

Abstract: A fast start-up system is disclosed for a transversal equalizer comprising a transmitter capable of generating a periodic symbol sequence with a period L, the auto correlation function of said sequence being 0, except for its center. The system generates and transmits a test signal based upon the generated symbol sequence. A receiver generates the same periodic symbol sequence as that generated in the transmitter in a proper phase relation thereto according to a received signal. The correlation between L sampled values and a sequence obtained by recirculating the periodic symbol sequence for each of consecutive M shifted phases, and for each of M' consecutive shifted phases is calculated. The calculated M+M' correlation values are multiplied by a constant. A discrete Fourier transform is obtained for the M+M' multiplied correlation values at N points equal to or greater than M+M' in number.

Abstract: An adaptive diversity receiver for digital communications provides a plurality of transversal filters disposed in front of a linear combiner for each of a plurality of diverse channels. The tap gains of each of the transversal filters are updated to estimate the sampled values of the channel impulse response for each diverse channel as a function of the detected data output, rather than providing tap gain updating as a function of the data error signal. In this manner, each transversal filter operates as an adaptive match filter for the corresponding diversity channel.