Abstract: A method and system for generating single and multi-channel optical analog pulse-position modulation waveforms are disclosed. The system comprises a frequency modulator, a continuous wave optical source, and an optical modulator. The frequency modulator receives the analog signal and converts the analog signal into a frequency modulated signal. The optical modulator modulates the continuous wave optical source with the frequency modulated signal, to produce the optical pulse-position modulated signal. The method comprises converting an analog input signal into a frequency modulated signal amplifying the frequency modulated signal and producing a large signal therein, modulating a continuous wave optical source with the large signal, therein producing the optical pulse-position modulation signal, and compressing the optical pulse-position modulation signal, therein increasing a processing gain.

Abstract: A system in which a personal computer sends messages into a TCP/IP network using a conventional dial-up link and downloads data from the TCP/IP network using a high-speed one-way satellite link. A preferred embodiment uses a conventional SLIP provider to connect to the TCP/IP network and uses a commercial software TCP/IP package that has a standard driver interface. A spoofing protocol compensates for the long propagation delays inherent to satellite communication.

Abstract: A signal processing circuit for satellite communications signal includes a first one dimensional digital beam forming circuit for forming a beam signal in a first direction and a second one dimensional digital beam forming circuit for forming a beam in a second direction. A direction filtering circuit is coupled between the first one dimensional digital beam forming circuit and the second one dimensional digital beam forming circuit. The filtering circuit determining a communications signal direction of the satellite communications signal and tunes the filter to reduce a filter bandwidth and a frequency range of said beam signal prior to processing through the second one dimensional digital beam forming circuit.

Abstract: A method of making a micro electromechanical switch or tunneling sensor. A cantilevered beam structure and a mating structure are defined on a first substrate or wafer; and at least one contact structure and a mating structure are defined on a second substrate or wafer, the mating structure on the second substrate or wafer being of a complementary shape to the mating structure on the first substrate or wafer. A bonding layer, preferably a eutectic bonding layer, is provided on at least one of the mating structures. The mating structure of the first substrate is moved into a confronting relationship with the mating structure of the second substrate or wafer. Pressure is applied between the two substrates so as to cause a bond to occur between the two mating structures at the bonding or eutectic layer. Then the first substrate or wafer is removed to free the cantilevered beam structure for movement relative to the second substrate or wafer.

Abstract: Electronic television program guide information is downloaded, stored and searched by a local device. A plurality of linked lists are used to remove redundancy, increase search speed, and allow dynamic categories. When a new category is encountered a new head node for a link list data structure is created. When a first program guide object containing information related to that category is downloaded, a link is made (i.e., a pointer is stored) from the head node to the guide object. When subsequent program guide objects containing information related to that category are downloaded, links are added to the end of the list or inserted in alphabetical order. As guide objects expire the links are removed. When no links remain in a particular category the head node for that category is deleted.

Abstract: An electronic document delivery system and method in which a broadcast center periodically sends a “catalog” of available documents to a receiving computer, thereby allowing a user to browse through the available documents without having to access the broadcast center. The documents are transmitted as packets, and the packets are decrypted as soon as they are received, eliminating the need to store both an encrypted and an decrypted version of the documents at the receiving computer. The receiving computer periodically receives information allowing it to decrypt received documents and to encrypt billing information for the receiving computer. The invention is not limited to text-only documents and can receive all types of documents, such as software, images, text, and full-motion video.

Abstract: A method and apparatus of broadcasting is provided that has a geographic identifier memory, an overlay memory storing an overlay, a receiver circuit for receiving a broadcast signal and a control circuit. The control circuit displays the overlay on the broadcast signal in response to the geographic identifier.

Abstract: A system and method for monitoring direct broadcast satellite signals. In a most general embodiment, the invention (10) includes a mechanism (20) for receiving direct broadcast wireless signals encoded in accordance with a DSS transport protocol. The received signals are analyzed with respect to various parameters and an output is provided in response thereto. In a specific embodiment, the wireless signals are transmitted via satellite and plural integrated receiver decoders (20) are used, one with an associated channel, to receive the wireless signals and provide audio, video, program guide and conditional access signals in response thereto. These signals are analyzed by software (100) running on a computer (56) which outputs alarm data on the detection of anomalies in the received signals.

Abstract: A communications system (10) and method of operating the communications system includes a high altitude communication device (12) that communicates with a plurality of user terminals and a gateway station (30). The gateway station (30) couples the users to terrestrial networks (32) and other users. The high altitude communication device (16) has a controller that generates a second beam having the first frequency to a service (26). The stratospheric platform (12) does not generate the second beam within a blocking area. User terminals within the service area outside the blocking area are configured to receive the first beam and the second beam.

Abstract: An approach is provided for multicasting of a list of network addresses that are pre-loaded into caches of the terminals. The list can be generated based on popularity of the domain names, by tracking, for example, hit counts. A predetermined number of the domain names are selected for multicast to the terminals over, for example, a fixed, low bit rate. Upon receipt of the multicast of the list, the domain names are loaded into the terminal's cache in advance of any request by a host to access a device associated with the pre-loaded domain names. This approach as particular applicability in relatively high latency networks, such as a satellite communications system.

Abstract: An approach for minimizing variation in transmit power of synchronized signals that are destined to a satellite is disclosed. A gateway station system for communicating with a communication satellite includes a multiple signal sources which generate the synchronized signals. The gateway station system utilizes a control logic that is coupled to the signal sources. The control logic operates to offset selectively transmission times of a portion of the synchronized signals according to a predetermined distribution and an offset period. The predetermined distribution specifies about half the number of the synchronized signals are to be offset. The offset period is half a symbol period. The terminals within the satellite communication system has a receiver that receives the synchronized signal from the communication satellite.

Abstract: A satellite communication system has a first deployment of a plurality of satellites deployed in a medium earth orbit and two later deployments of a plurality of satellites deployed in the medium earth orbit. The first deployment is, spaced so that the second deployment may be easily deployed and interleaved into the first deployment. A ground terminal is used for communicating with the satellites in the first and second deployments.

Abstract: A method of providing forward error correction for data services uses a parallel concatenated convolutional code which is a Turbo Code comprising a plurality of eight-state constituent encoders wherein a plurality of data block sizes are used in conjunction with said Turbo Code. A variation uses the method in a cellular radio system. Another variation uses the method in both forward and reverse likes of a cellular radio system.

Abstract: An approach for identifying a particular carrier among a plurality of carriers in a satellite communication system is disclosed. A transmitter multiplies an encoded signal by a prescribed periodic sequence to form a watermarked signal and transmits the watermarked signal associated with a particular carrier over a communication channel. A receiver tunes to one of the carriers and extracts a data sequence from the one carrier. The receiver multiplies the data sequence with the prescribed periodic sequence to form another watermarked signal and determines whether the watermarked signals match.

Abstract: A first transmitting device is used to transmit a first signal on a first carrier frequency to a relay device. The relay device receives the signal by demodulating the first carrier frequency. Subsequently, the relay device retransmits the signal by modulating a second and/or a third carrier frequency. The signal is then recovered at one or more receiving devices by demodulating the second and/or third carrier frequencies. Further, a second transmitting device transmits a second signal on a fourth carrier frequency and the relay device retransmits the signal by modulating a fifth and/or a sixth carrier frequency. The signal is then recovered at one or more receiving devices by demodulating the fifth and/or sixth carrier frequencies. The transmitting and/or receiving devices are preferably voice terminals, such as a wireless telephones or data terminals, such as portable computers.

Abstract: A method and apparatus for generating a database in a memory. Program identifying information is received from a service provider, the program identifying information comprising at least one service provider search criteria and information describing a channel on which a program is transmitted. A database is generated in a memory as a function of the channel identifying information and at least one of the service provider search criteria. Preferably, user-input search criteria is also received and it is determined whether the user-input search criteria corresponds to the service provider search criteria. A channel identified by the channel identifying information is selected if the user-input search criteria corresponds to the service provider search criteria.

Abstract: A satellite-based communications system operating at high data rates includes a plurality of satellites each having uplink and downlink antennas for transmitting and receiving a plurality of signals utilizing a plurality of spot beams to and from a plurality of coverage areas at a predetermined range of frequencies. The system can include, or be combined with, other systems to enable increased capacity over high population areas and ubiquitous coverage over lower population areas. A portable antenna assembly can be coupled to a user's portable or mobile electronic device for coupling the electronic device directly to a satellite. A routing switch provides routing and switching on-board the satellite and routes signals according to their desired destination.

Abstract: An ATM network comprises a central call processor, and one or more remotely located ATM bridge nodes, whereby the call processor is separated from the switching fabric in the ATM bridge nodes. A plurality of preestablished permanent virtual paths are defined within the ATM bridge nodes. In setting up a connection, a source user terminal communicates with the central call processor to obtain the virtual path identifier associated with the virtual path to one or more destination user terminals. The user data is segmented into one or more cells that incorporate a header containing the appropriate VPI. The ATM bridge node extracts the VPI from incoming cells, and then directs these cells to the appropriate output ports in accordance with a routing table. The instant invention provides for improved network efficiency and upgradability, and is particularly suited to satellite based ATM networks.

Abstract: A payload design for a multi-spot-beam satellite communication system includes a plurality of uplink spot beam receivers and downlink spot beam transmitters, and a broadcast transmitting subsystem capable of transmitting a broadcast beam to an entire system geographical service area. An input filter-switch-matrix (IFSM) controllably selects input IF signal bands for routing to an on-board digital signal processor-router (DSPR). The DSPR subsequently routes all received point-to-point and broadcast data packets to the appropriate downlink spot or broadcast transmitting subsystems for transmission thereof. The broadcast downlink allows broadcast transmissions to occur at the highest efficiency possible, while also allowing for flexible provision of surge capacity for point-to-point transmissions on previously exhausted spot beams by selective use of the broadcast beam for such point-to-point transmissions.

Abstract: A system in which a personal computer sends messages into a TCP/IP network using a conventional dial-up link and downloads data from the TCP/IP network using a high-speed one-way satelite link. A preferred embodiment uses a conventional SLIP provider to connect to the TCP/IP network and uses a commercial software TCP/IP package that has a standard driver interface. A spoofing protocol compensates for the long propagation delays inherent to satellite communication.