Abstract: An apparatus and method for use in an optical system. An in-line optical wavelength reference and control module (WRCM) is inserted in series with an optical fiber signal path between an input fiber and an output fiber. The WRCM includes an input lens, a multi-element grating and an output lens. The input lens couples an input optical signal from the input fiber into the multi-element grating. The multi-element grating includes low-efficiency gratings which reflect portions of the input optical signal having different predetermined characteristics to different detectors of a detector array, while transmitting the remaining portions of the input optical signal to the output lens. The output lens couples the transmitted portions of the optical signal back onto the optical signal path. The WRCM may thus be placed directly in series with an optical signal path.

Abstract: An InP-based opto-electronic integrated circuit including an active layer having one or more quantum wells (36, 38). According to the invention, a barrier layer (34) of AlGaInAs is formed, preferably between the quantum wells and the substrate (30) to prevent the migration of species from the substrate and lower InP layers that tend to shift the emission wavelengths of the quantum wells to shorter wavelengths, i.e., a blue shift. The barrier layer can be patterned so that some areas of the quantum wells exhibit blue shifting to a shorter wavelength while other areas retain their longer wavelength during annealing.

Abstract: An apparatus and method for combining video signals from multiple users in a continuous presence video conferencing system. Video signals are received from each of a number of different system users. The signals include input frames each having a number of different groups-of-blocks (GOBs). The GOBs correspond to hierarchically organized video data and header information. The input frame GOBs are used to form a composite output video signal suitable for transmission to each of the system users. An output frame of the composite output signal incorporates at least one of the GOBs from the input frames of each of the users and less than all of the GOBs from the input frame of at least one of the users. The resulting output video signal provides flexible continuous presence video conferencing in which video signals from multiple users may be simultaneously displayed to all users in a selected divided-screen format.

Abstract: The cycling stability and capacity of Li-ion rechargeable batteries are improved, particularly in an elevated temperature range of about 55.degree. C., by the use of lithium aluminum manganese oxy-fluoride electrode components having the general formula, Li.sub.1+x Al.sub.y Mn.sub.2-x-y O.sub.4-z F.sub.z, where x.ltoreq.0.4, 0.1.ltoreq.y.ltoreq.0.3, and 0.05.ltoreq.z.ltoreq.0.5.

Abstract: A method for the direct reconstruction of the absorption and diffusion images from measurements of the transmitted intensity of the scattered radiation effected by irradiating the object with a time-domain source. The transmitted intensity is related to the absorption and the diffusion coefficients by an integral operator. The images are directly reconstructed by executing a prescribed mathematical algorithm, as determined with reference to the integral operator, on the transmitted intensity.

Abstract: In a telecommunications network, a method is provided for reading a desired telephone data record associated with a given telephone number from a line record database. Initially, a data processor reads data from an accessing data record stored in an index database. The accessing data record contains at least an accessing number designating a series of telephone numbers including the given telephone number, a pointer pointing to a data cluster in the line record database, and a blocking factor associated with the data cluster. The data cluster comprises a plurality of data nodes and includes all of the telephone data records associated with the series of telephone numbers designated by the accessing number. Each data node contains a number of individual telephone data records up to the blocking factor and a number of pointers each pointing to one of the number of individual telephone data records. The data processor accesses a data cluster based on the data read from the index database.

Abstract: A horizontally asymmetrically dilated optical switch comprising multiple stages of 2.times.2 optical switching units, especially electro-optic switching units such as acousto-optical tunable filters (AOTFs), which are electrically switchable between a bar state and a cross state to route and switch an optical signal through the switch. The switch is dilated that is, the switching units have an unused input or output so as to dump crosstalk terms into unused outputs. According to the invention, the interconnections between the switching units and their control are such that any optical signal and any crosstalk path passes through equal numbers of bar-state switches and of cross-state switches. Thereby, two advantages are gained. First, no switching path is transparent to a wide bandwidth so that noise cannot recirculate in an amplifying path and go into oscillation. Also, if one state or the other produces greater crosstalk, along no switching path is the larger term accumulated more than the smaller term.

Abstract: An ISCP gateway connects an ISCP to the Internet. Internet call processing records ("CPRs") are generated and stored in a database associated with the ISCP. These Internet CPRs translate logical addresses in the URL standard to physical worldwide Web ("WWW") addresses in the URL standard. Hyperlinks Web documents are modified to include logical addresses. Browsers send requests containing logical addresses associated with hyperlinks to the ISCP gateway, which forwards the request to the ISCP. The ISCP executes a corresponding Internet CPR and returns a physical address to the Web browser. The Web browser then requests a document identified by the physical address in a normal fashion.

Abstract: Methods and apparatus are disclosed for re-initializing a secure password series based on an iterated hash function. User login information is communicated over an insecure network connection or other transmission medium between a client and a server. The server provides an indication that a first login series based on a first password has reached a predetermined minimum number of remaining hash function iterations. This indication could also be generated by the client. In either case, the client responds to the indication by generating an initialization signal which relates the first login series based on the first password to a second login series based on a second password. The initialization signal may be generated as the exclusive-or of the results of applying a first number of hash function iterations to the first password and a second number of hash function iterations to the second password.

Abstract: A novel process for making Li.sub.x Mn.sub.y O.sub.4 intercalation compounds, wherein 0<x.ltoreq.2 and 1.7.ltoreq.y.ltoreq.2, comprises the steps of: (1) synthesizing a lithiated manganese oxide precursor by reacting lithium hydroxide, manganese dioxide, and one or more polyhydric alcohols; and (2) heat-treating the lithiated manganese oxide precursor. The intercalation compounds are effectively employed as active components of positive electrodes in rechargeable lithiated intercalation battery cells.

Abstract: A method for the direct reconstruction of an object from measurements of the transmitted intensity of the scattered radiation effected by irradiating the object. The transmitted intensity is related to the image by an integral operator. The image is directly reconstructed by executing a prescribed mathematical algorithm, as determined with reference to the integral operator, on the transmitted intensity.

Abstract: An optical filter, such as a wavelength-division multiplexer, demultiplexer, or optical router, in which several single-mode waveguides are coupled to the sides of an optical interaction region containing a wavelength dispersive element that collects light from one or more input waveguides inputting light to the interaction region and disperses it according to wavelength to one or more output waveguides outputting wavelength-separated light. According to the invention, a multi-moded waveguide is interposed between one or more of the single-moded waveguides and the optical interaction region. It has a predetermined length to create at one end a multiply peaked image of a singly peaked profile presented to it at the other end, thus being a multi-mode interference (MMI) filter that presents a flatter filter profile at the interface between the MMI and the optical interaction region and affords reduced filter sensitivity to wavelength drift of an optical signal.

Abstract: A personal communications internetwork provides a personal communications internetwork providing a network subscriber with the ability to remotely control the receipt and delivery of wireless and wireline electronic text messages. The network operates as an interface between wireless and wireline networks. The subscriber's message receipt and delivery options are maintained in a database which the subscriber may access by wireless or wireline communications to update the options programmed in the database.

Abstract: A person communications internetworking provides a network subscriber with the ability to remotely control the receipt and delivery of wireless and wireline voice and text messages. The network operates as an interfaces between various wireless and wireline networks, and also performs media translation, where necessary. The subscriber's message receipt and delivery options are maintained in a database which the subscriber may access by wireless or wireline communications to update the options programmed in the database. The subscriber may be provided with CallCommand service which provides real-time control of voice calls while using a wireless data terminal or PDA.

Abstract: A video conferencing system and method that uses a central multimedia bridge to combine multimedia signals from a plurality of conference participants into a single composite signal for each participant. The system gives each conference participant the ability to customize their individual display of other participants, including keying in and out selected portions of the display and overlapping displayed images, and the ability to identify individual images in a composed video stream by click and drag operations or the like. The system uses a chain of video composing modules that can be extended as necessary to combine video signal streams from any number of conference participants in real time. Multimedia association software is provided for associating different media types to enhance display and manipulation capabilities for multimedia uses. The system also allows each user to dynamically change who can receive the information they provide to the conference.

Abstract: A method and apparatus providing reducing crosstalk in optical cross-connects by configuring unused switching elements into a common switch state. The optical cross-connect may be a 2.sup.N .times.2.sup.N cross-connect which includes a plurality of dilated 2.times.2 switches each having a number of switch elements. A group of the switch elements connected between one or more inputs and one or more outputs of the cross-connect are suitably configured to provide one or more desired optical signal paths through the cross-connect. Unused cross-connect switch elements which are not part of any desired optical signal path are configured such that any unused switch elements in a given dilated 2.times.2 switch are placed in a common cross or bar switch state. The resulting cross-connect outputs will include at most one second order crosstalk term, as compared to conventional switch configurations in which a cross-connect output may have up to N second order crosstalk terms.

Abstract: An access point 220 is provided with an access link 212 to a first host 210. The access point 220 has a first link 231 to a wide area network 230 which is the Internet backbone. Packets are communicated on the wide area network 230 using a best effort scheme at an uncontrollable, unpredictable and fluctuating rate. Neither the first host 210 nor the access point 220 are capable of selecting or controlling the rate at which packets are transmitted on the wide area network 230. The access point 220 also has a second link 261 to a guaranteed bandwidth network 260. The access point 220 is able to, on demand, establish a continuous bandwidth channel on the guaranteed bandwidth network 260 with an arbitrary other access point 240, to which another host 250 is connected, at a particular continuous packet transfer rate. The first host 210 can generate a packet requesting that the access point 220 establish a continuous bandwidth session with a second host 250.

Abstract: A birefringence-free semiconductor waveguide comprising on a substrate a plurality of layers some of which are in tensile strain with respect to the substrate and others of which are in compressive strain. Birefringent-free behavior with respect to a guided light signal traveling in the waveguiding structure and possessing a photon energy lower than the bandgap of the constituent waveguide layers is obtained when birefringence introduced into the individual layers of the waveguiding structure by the strain is sufficient to compensate for the intrinsic geometric modal birefringence of the waveguiding structure that exists in the case where all layers are not strained.

Abstract: Methodology and concomitant circuitry to generate cryptographically strong pseudo-random bit streams utilize secure block cypher encoders. Each block cypher encoder has a random key and a first seed as an input, and the output of each encoder is fed back to connect to its input. The first seed serves as the initial input, and each subsequent input is the immediate output of the block cypher encoder. Each bit in the cryptographically strong pseudo-random bit stream is related to a first inner product between input to the block cypher encoder and a second seed and a second inner product between the random key and a third seed.

Abstract: A technique for controlling the transmission power level of a transmitter, particularly in a wireless personal communication system, is disclosed. This technique assists in the prevention of interference between transceivers from degrading the quality of transmissions. Transmission power level is controlled through a hybrid circuit containing both digital and analog electronics. The transmission power level is set by controlling both the amount by which a data stream is compressed and the gain of an analog transmit power amplifier. This approach allows adequate control over the transmission power level; it avoids the need for utilizing excessively wide data paths for the digital transmit signals (which may compromise portable terminal battery consumption), or utilizing expensive, hard-to-calibrate analog electronics.