Abstract: Methods of imaging objects based on wavelet retrieval of scenes utilize wavelet transformation of plural defined regions of a query image. By increasing the granularity of the query image to greater than one region, accurate feature vectors are obtained that allow for robust extraction of corresponding regions from a database of target images. The methods further include the use of sliding windows to decompose the query and target images into regions, and the clustering of the regions utilizing a novel similarity metric that ensures robust image matching in low response times.

Abstract: A portable wireless communication terminal includes electronics for receiving and transmitting both video and audio signals. The electronics are housed in rugged, drop-tolerant consoles, which are interconnected so that they may be extended and reconfigured relative to each other for convenient use and easy, compact storage. A camera lens is included in a camera console, a video display is included in a video display console, and alphanumerical keys are included in a base console. The camera console can be rotated relative to the video display console so that the user can transmit a video signal of the surroundings while watching the video display. Further, the video display console can be extended and tilted relative to the base console.

Abstract: A method and apparatus for measuring polarization mode dispersion in a transmission system. The method allows polarization mode dispersion to be measured concurrent with data transmission in the transmission system.

Abstract: A side tone generator which adjusts gain to compensate for echo effects is described. The side tone generator includes a gain unit which receives a voice signal and applies a gain to the voice signal to produce a side tone, and a summing unit which adds the side tone to a speech decoder signal. The side tone generator also includes a side tone gain adapter to adjust the gain added by the gain unit. The side tone gain adapter computes a default gain which would be applied in the absence of echo and multiplies the default gain by an echo correction factor based on the prevailing level of echo in order to determine the gain to be applied. In another embodiment, an echo canceller employs a filter which receives a filter input based on a speech decoder signal and produces a filter output reflecting an estimate of echo present in the speech decoder signal. The echo canceller also includes an output summing unit which subtracts the filter output from a voice signal to produce an echo canceller output.

Abstract: A method for increasing the capacity of a communication network by assigning subscribers of the communication network to individual antennas of an antenna array and allowing the antenna array to convey information to the assigned subscribers under the control of a scheduling algorithm. Antennas—under the control of the scheduling algorithm—in the antenna array are thus able to convey information to different subscribers at different times. The scheduling algorithm determines when to convey information to an assigned subscriber based on channel condition information it receives from the subscribers. The scheduling algorithm also uses the channel condition information to assign certain subscribers to certain antennas.

Abstract: A system and method for acoustic modeling partitions an input 3D spatial model into convex cells, and constructs a cell adjacency data structure representing the neighbor relationships between adjacent cells. For each sound source located in the spatial environment, convex pyramidal beams are traced through the input spatial model via recursive depth-first traversal of the cell-adjacency graph. During beam tracing, a beam tree data structure is constructed to encode propagation paths, which may include specular reflection, transmission, diffuse reflection, and diffraction events, from the source location to regions of the input spatial model. The beam tree data structure is then accessed for real-time computation and auralization of propagation paths to an arbitrary receiver location.

Abstract: Fiber is drawn from a preform comprising a silica body, e.g., a sol-gel derived overcladding or substrate tube. Prior to sintering, the body is treated with a gaseous mixture containing one or more non-oxygenated sulfur halides, to remove and/or reduce the size of refractory oxide particles, and/or dehydroxylate the body. Removal of metal oxide particles or reduction in their size contributes to drawing of optical fiber exhibiting desirable strength, since such particles act as initiation sites for breakage. Advantageously, the halides include sulfur chlorides, which provide desirable improvements compared to treatment by oxygenated sulfur chlorides such as thionyl chloride (SOCl2).

Abstract: In accordance with the invention, a tunable, reconfigurable optical add-drop filter comprises a pair of optical waveguides optically coupled by a microring or microdisk resonator wherein the coupling distance between the resonator and at least one of the waveguides is micromechanically controllable. With this arrangement, the degree of coupling can be tuned after fabrication to provide high level extinction of dropped wavelengths and the filter can be dynamically reconfigured. Advantageously, laser radiation is provided to tune the resonant wavelength.

Abstract: The present invention uses wavelength conversion to increase the bandwidth of optical communication systems. In an exemplary embodiment, a combination of wavelength conversion and amplification with a discrete optical amplifier (OA) to allow communications systems to operate in wavelength bands &lgr;′ outside the gain bandwidth of the OA. A transmitter launches signal channels (&lgr;1′, &lgr;2′, . . . , &lgr;′N) that are outside the gain bandwidth &lgr;. A wavelength conversion device upstream of the amplifier maps channels &lgr;′1, &lgr;′2, . . . &lgr;′N to corresponding wavelengths &lgr;1, &lgr;2, . . . &lgr;N within &lgr;. The OA directly amplifies the converted signals and a second wavelength conversion device downstream of the amplifier maps the amplified signals back to the original channels &lgr;′1, &lgr;′2, . . . &lgr;′N.

Abstract: The invention pertains to methods and apparatus for determining when and how to perform communication network congestion control tactics, such as call blocking, with respect to packet-based networks.

Abstract: Template-based methods fabricate organosilicate materials with mesoscopic structures. The methods include providing solutions of amphiphilic template molecules, mixing amphiphilic organosilicate precursors into the solutions to form mixtures, and evaporating solvent from the mixtures. The evaporation steps produce composites in which the amphiphilic organosilicate precursors have nontrivial mesoscopic structures.

Abstract: In a multiple access communications system data to be transmitted to a particular end-user receiver is processed with a specific process assigned to the particular end-user. The processing is such that an output array of data bits after processing has the same number of bits as an input array of data bits but is unique to the particular end-user. Then, the data is only recoverable at the end-user receiver by using a process that is the exact inverse of the process employed at the transmitter and assigned to the particular end-user receiver. Consequently, the data is identified to the particular end-user without having to transmit additional identification information.

Abstract: Various methodologies and related apparatus associated with mobility management issues within a packet-based multiaccess mobile communications system, which includes a plurality of mobile user stations and a plurality of network nodes, are provided. Location management techniques include tracking and/or locating mobile stations within the system. The invention makes use of home and visiting location registers in which information such as mobile station addresses and/or host names associated with mobile stations are stored. Mobile access methodologies include a complete mobile access method and a direct mobile access method. The former allows a mobile station to preferably include a unique address in the packets being transmitted, while the latter allows the station to merely use the host name of the destination station. The invention also includes various in-call mobility management techniques, including handoffs, which make use of the concept of an anchor.

Abstract: A communication system and method for allocating overhead voltage between a telephonic switch and a user device is described. A line driver is located in the telephonic switch and is coupled to the user device. The line driver is in one of a plurality of communication states. A processor, coupled to the line driver, allocates the overhead voltage in response to the communication state of the line driver.

Abstract: A system and method to provide cost effective, portable and convenient access to the Internet and other personal computer applications from any location within a predetermined distance from a desktop personal computer (PC). According to one aspect, a compact handheld terminal functions as a user interface device and communicates via an FM frequency hopped radio link with a base station which is located near and connected with the desktop PC. The handheld terminal allows home users to conveniently and remotely interface with their desktop PC with a freedom of movement similar to that of using a laptop PC while allowing an inexpensive network connection. The FM frequency hopped radio link carries the appropriate video, audio, keyboard and mouse signals between the desktop PC and the handheld terminal. The approach may be adapted to short range transfer of high quality video in a variety of applications.

Abstract: A transmission system encodes blocks of source data with error correction codes and spreads encoded data for each source block over a range of time and frequencies. This has the effect of reducing the impact of flat fading. This is because if a portion of the encoded data corresponding to a block of source data is lost, as a result of flat fading during a time interval, other portions, transmitted at a different time, may not be affected. A receiving system may therefore recover the original block of source data based on the portions of the encoded data that were received, including error correction bits. The transmission and receiving systems may be orthogonal frequency division multiplexed (OFDM) communications systems.

Abstract: A system that provides additional voice lines with data over a single two-wire subscriber loop. At the subscriber premise, one or more telephone instruments and data devices are connected to a digital modem into either a voice or a data interface. Analog voice signals are PCM sampled then packetized, and voice and data packets are transmitted to a CO modem over the subscriber loop. The CO modem depacketizes the voice packets into PCM format and transmits PCM voice information to a CO switch over a standard digital trunk interface. Data packets are routed to a data network. Voice packets are given transmission priority over data packets to ensures that voice is transported in the presence of data with low latency.

Abstract: In accordance with the invention, the optical power level in an optical waveguide is monitored by enclosing a length of the waveguide within an insulated cavity of comparable length and cross section, measuring a first temperature T1 within the cavity, measuring a second temperature T2 outside the cavity and deriving from the difference, T1−T2, a measure of the optical power level. Exemplary apparatus for monitoring the optical power level in an optical waveguide comprises a substrate with an insulated groove for receiving an optical fiber, an insulated lid for sealing the fiber within the groove, and internal and external temperature sensors.

Abstract: The invention comprises a method and apparatus for implementing a relatively low cost add/drop multiplexer (OADM) wherein pre-demux and post-mux dispersion compensation is employed in a manner that substantially avoids imparting additional dispersion compensation to pass-through wavelength channels in a WDM system.

Abstract: The method for transferring data sends the data as part of a first permanent identifier associated with an end user in a communication system. The first permanent identifier is sent along with a second permanent identifier, also associated with the end user, during a communication procedure prior to establishing a traffic channel in the communication system. Besides the data, the first permanent identifier includes routing information to a home system forming part of the communication system. Based at least in part on recognizing the second permanent identifier, a home system sends at least the first permanent identifier to a destination entity. The destination entity extracts the data from the first permanent identifier. In this manner, a traffic channel does not need to be established to transmit the data.