Abstract: An optical attenuator having a structure in which a membrane covers a cavity formed on a substrate is disclosed. The membrane covering the cavity formed in the substrate is movable relative to the bottom surface of the cavity constituting a deformable mirror. Movement of the membrane relative to the bottom surface of the cavity attenuates optical signals impinging on the surface thereof. The movement of the membrane relative to the bottom surface of the cavity attenuates impinging optical signals by controlling the angle at which such impinging optical signals are reflected from the membrane surface.

Abstract: In a system for sending wireless communication signals on at least one downlink wavelength and receiving wireless communication signals on at least one uplink wavelength, there is a ratio r equal to the larger divided by the smaller of these wavelengths. The system comprises a receiver operative to receive signals imposed on a carrier having the uplink wavelength, a transmitter operative to transmit signals imposed on a carrier having the downlink wavelength, and an array of independent antenna elements. The array comprises a first and a second sub-array. One sub-array is electrically coupled to the transmitter, such that transmitted signals can be radiated from it, and the other sub-array is electrically coupled to the receiver, such that signals to be received can be extracted from it. The sub-arrays are geometrically similar to each other with a relative scale factor equal to the wavelength ratio r. The sub-arrays have at least one common antenna element.

Abstract: A system and method that provides control of a conference call. A controlling party enters a code and is isolated from the conference. Each conference participant is sequentially connected to the controlling party so that the controlling party may determine the noise level on that leg of the call. If there is no excess noise, then the controlling party may enter a code which causes the switch to select the next party on the conference call. When the controlling party discerns the offending conference participant, the controlling party can signal the switch to drop the offending party. The controlling party may then rejoin all of the conference participants.

Abstract: A holographic storage medium, a method of manufacturing the holographic storage medium and a holographic storage device incorporating the storage medium. In one embodiment, the holographic storage medium includes: (1) first and second spaced-apart substrates, the first substrate being plastic and (2) a photopolymer core located between said first and second substrates and having a coefficient of thermal expansion such that said first and second substrates and said photopolymer core cooperate to respond substantially isotropically to a change in temperature.

Abstract: A method that uses a test system at one end of a communication link to test the communication link for high speed service by coupling the test system to the communication link, placing a telephonic call to telephonic equipment located at an other end of the communication link and testing the communication link with the test system after the call has been terminated at the telephonic equipment.

Abstract: A base station with a defined geographic coverage area in a wireless communication system includes a base receiver, a base transmitter, and a base antenna array. The base antenna array has a base station beamformer arranged to produce (a) a broad antenna beam so that the base station can receive random access signals from subscriber stations at different locations within the coverage area and transmit beacon or acknowledgment signals to the subscriber stations at the different locations, and (b) a narrow antenna beam directed to an acknowledged subscriber station for receiving or transmitting data or traffic signals from or to the subscriber station. A subscriber station includes a subscriber receiver, a subscriber transmitter and a subscriber antenna. The subscriber transmitter is arranged to transmit signals to a system base station on one or more of a number of carriers having a defined frequency spacing within a given spectrum allotment.

Abstract: A subscriber conversion system determines at least one code for an existing subscriber of a first wireless communications system to be converted to a second wireless communications system. When the existing subscriber obtains a wireless unit to be used in the second wireless communications system, the conversion system uses the at least one code provided to the existing subscriber to link existing subscriber information from the first wireless communications system to information associated with wireless unit for the second communications system, thereby improving the efficiency of the conversion process. For example, if a service provider wishes to convert from GSM to CDMA, the service provider can provide a secret code and an identification number, such as a directory number (DN), as the codes to the existing GSM subscriber. The subscriber obtains a CDMA wireless unit and commences an activation process to activate the CDMA wireless unit.

Abstract: An optical receiving system includes a Fresnel lens optically coupled to a detector via a tapered concentrator. The Fresnel lens is adapted to receive an electromagnetic signal and has a Fresnel focal point. The tapered concentrator has a first end surface area larger than a second end surface area. The detector has a sensing surface area oriented to receive the electromagnetic signal emerging from the tapered concentrator.

Abstract: In an emergency evacuation reporting system and method, a number of normally open illuminated push button switches are distributed throughout a facility at all normal and alternate exit routes for each area. The push button switches are connected to a command center for the facility. When an emergency area is evacuated, the LEDs representing the affected areas in the facility are energized red on a status panel in the command center. As the evacuation wardens verify each area clear of personnel, they press the most convenient push button switch for their area. This changes the red LED at the status panel to green and also illuminates the push button switch in the affected area.

Abstract: The specification relates to a method and apparatus supporting multiple access, bi-directional data and multimedia transfer described over a hybrid fiber/coax (HFC) network, though applicable to transmissions over other media as well. The protocol associated with the present invention supports downstream broadcast transmission from headend to cable modem, and also provides for allocation of bandwidth for cable modems to transmit back to the headend. The protocol supports different access modes such as STM, ATM, and VL; within each subframe of a subframe/frame/masterframe structure. The protocol is utilized over a system which provides for forward error correction (FEC) and scrambling/descrambling, while eliminating the deleterious effects on the error correcting capability of the FEC due to the bit error spreading associated with a scrambling/descrambling function.

Abstract: A novel data structure in a router helps to compute viable next hops for forwarding a data packet from a router to its destination along multiple alternate loop-free paths, which are not necessarily of shortest distance. Each viable next hop may also be specified with a degree of optimality, which enables a route to perform QoS routing and fault-tolerant routing efficiently. The data structure can be implemented as an add-on software to existing routing protocols and may be implemented in existing networks which use shortest path protocols, even where less than all of the routers use the data structure and multiple path scheme described herein.

Abstract: An orthogonal frequency division multiplexing (OFDM) technique which is time division multiplexed to reduce the overall effect on individual services from conditions such as selective fading. In accordance with the principles of the present invention, all available subcarriers in a channel are assigned to fewer than all of the requesting services, e.g., to just one particular service for a period of time. The period of time is preferably independent of the length of a conventional data frame. Thereafter, a second service is assigned access to the use of all available subcarriers for a period of time corresponding to its required bandwidth, and so on until all requesting services are allotted a portion of time for access to all available subcarriers. Any one service may utilize any number of the available subcarriers in a particular superframe containing one cycle of transmissions for all services.

Abstract: A transaction processing system comprises a querying system and a logical database having an active database and a backup database. The querying system transmits a message for a transaction to the logical database for processing. The message is transmitted to the active database where the message is processed. The active database creates transaction state data based, in part, on the message. The active database transmits a response message to the querying system and forwards the original message to the backup database. The backup database processes the original message and creates its own transaction state data. The transaction state data in the backup database operationally matches the transaction state data in the active database so that if the active database fails, the backup database includes the requisite transaction state data necessary to complete the transaction. The querying system processes the response message and transmits a termination message to the logical database for processing.

Abstract: An antenna is described that comprises an antenna having a patch element fabricated onto a substrate, a ground plane, and an impedance transformer between the patch element and the ground plane. The patch element electrically connected to a first end of the impedance transformer, and a feed line is electrically connected to a second end of the impedance transformer through the ground plane. The use of the impedance transformer allows impedance matching to be accomplished without being limited by the physical limitations of the patch element. According to a further aspect of the invention, a patch element is fabricated onto a first substrate surface and a ground plane is fabricated onto a second substrate surface, the ground plane separated from the patch element by a plurality of substrate layers.

Abstract: A self-aligned clock recovery circuit for synchronizing a local clock with an input data signal includes a sampling type phase detector for generating an output signal based on the phase difference between the local clock and the data signal timing. The phase detector obtains samples of consecutive data symbols at sampling times corresponding to transitions of the local clock, and obtains a data crossover sample at a sampling instant in between those of the consecutive data symbol samples. A phase shifter is employed to phase shift the local clock by an amount corresponding to a time varying modulation signal so as to obtain each data crossover sample at a variable sampling instant relative to the associated consecutive symbol samples.

Abstract: A clamp for holding laser components during a facet coating process. The clamp includes a first elongate member for contacting a first side of the laser components and a second elongate member for contacting a second opposing side of the laser components. The first and second elongate members include first and second lands, respectively, for contacting and holding the laser components.

Abstract: A method for checking a property of a system modeled with a hierarchical message sequence chart is provided. To check a property of the modeled system, a temporal logic causality specification is defined. The specification is translated to a specification automaton, and an implementation automaton is constructed from the hierarchical message sequence chart. The intersection of the automata are then checked for emptiness.

Abstract: A finger assignment system prevents the assignment of receiver fingers to the same multipath component and to avoid the inefficiencies associated with current schemes. The finger assignment system accomplishes this by setting an offset or delay difference between the offsets or delays assigned to any two fingers, and if the offset or delay difference is violated, adjusting the offset(s) or delay(s) of one or both of the fingers to differ from each other by at least the offset difference. In certain embodiments, the receiver establishes an offset or delay difference between the offsets or delays assigned to any two fingers which are receiving signals from the same antenna. If the offset difference is violated, the finger assignment system adjusts the assigned offset or delay of the weaker finger to differ from the assigned offset of the stronger finger by at least the offset difference.

Abstract: The process of prototyping circuits such as a backplane or a circuit board has been modularized for achieving marked reductions in costs, time, and construction errors. Rather than repeating the recurring tasks, such as making bus connections between different circuit boards, of the prototyping process, the present invention implements a plurality of modules which can be separably coupled into an assembly having a planar arrangement for prototyping circuits, where each module specializes in a particular task. In the preferred embodiment, the plurality of modules includes a data bus module, a switchable data bus module, a power bus module, and a wire-wrap module. Each one of the plurality of modules includes a coupling face configured for coupling to one or more circuit boards.

Abstract: A multiple description (MD) joint source-channel (JSC) encoder in accordance with the invention encodes n components of a signal for transmission over in channels of a communication medium. In illustrative embodiments, the invention provides optimal or near-optimal transforms for applications in which at least one of n and m is greater than two, and applications in which the failure probabilities of the m channels are non-independent and non-equivalent. The signal to be encoded may be a data signal, a speech signal, an audio signal, an image signal, a video signal or other type of signal, and each of the m channels may correspond to a packet or a group of packets to be transmitted over the medium. A given n×m transform implemented by the MD JSC encoder may be in the form of a cascade structure of several transforms each having dimension less than n×m. The transform may also be configured to provide a substantially equivalent rate for each of the m channels.