Abstract: A system and a methodology to improve the end-user quality of service both in terms of response time and reliability for the transport of in-call DTMF signals in wireless systems, particularly in geostationary mobile satellite systems. The methodology encompasses several techniques to provide acceptable end-to-end quality of service for DTMF. A technique is applicable for transport of DTMF in the wireless subscriber to network direction, where DTMF digits are carried in the form of an out-band message. The central part of the technique is to allow multiple key presses in the same message, thereby increasing efficiency and throughput in long-delay environment. Another technique utilizes the vocoder's functionality to carry DTMF in-band, thereby reducing system complexity.

Abstract: A communications system has a high altitude communication device generates a plurality of user link beams having a first communication characteristic and a feeder link having a first communication characteristic. A gateway terminal receives the user link beam for receiving a first received signal and a second received signal thereafter. The receiver circuit has a recursive filter for generating differential amplitude of symbol timing estimate from said first received signal.

Abstract: A modulator produces a modulated signal including a carrier and data signals representing data bits. The data signals include at least two in-phase modulating pulses which have different shapes and which are interfering in time and frequency; the data signals further include at least two quadrature modulating pulses which have different shapes and which are interfering in time and frequency. The modulator includes a filter for producing each shape of pulse, and combining circuits for combining the pulses with each other and with a carrier. The demodulator (or receiver) receives the combined signal and separates the pulses from the carrier. The demodulator further includes filters for separating the pulses, and a circuit for processing the pulses to reproduce the data bits. The processing circuit preferably includes one or more maximum likelihood sequence estimation equalizers.

Abstract: An audio data file-handling device which may receive one or more audio data files from a base station. This file transfer may be accomplished utilizing wireless transmissions. Furthermore, the base station may accumulate one or more audio data files from a variety of content sources and communication paths. An audio data file distribution system which accumulates audio data files in a base station and uploads at least one accumulated audio data file to an audio data file handling device. A user interface, such as a wireless control unit, may send a trigger signal to the base station either directly or via the audio data file-handling device. This triggering signal triggers the upload of audio data files from the base station to the audio data file-handling device. The triggering signal may also be generated upon a vehicle start condition or upon the arrival of a designated time. Furthermore, cellular or other wireless networks may be utilized to transfer audio data files over long distances.

Abstract: A facsimile transmission relay apparatus, referred to as an Intelligent Facsimile Relay (IFR) for improving call success rates in long delay environment such as terrestrial cellular, fixed wireless, and geostationary mobile satellite systems and the like. A first bi-directional telecommunications interface is provided for receiving facsimile signals from a transmitting facsimile device via a first network such as a Public Switch Telephone Network (PSTN). A buffer memory is used by the IFR for storing the facsimile signal, and a second bi-directional telecommunications interface retransmits the facsimile signal via the second network.

Abstract: A system and method employing a rate matching algorithm for providing an optimized pattern for puncturing parity bits of a turbo encoded data word of a given rate to produce a turbo encoded data word of a desired lower rate, to thus eliminate bits from said turbo encoded data word to be transmitted by a transmitter. The system and method determine a final amount of bits to be transmitted in the encoded data word, and determine, based on the final amount of bits in relation to the original number of bits in the encoded data word, the number of parity bits to be eliminated from transmission in the encoded data word. Because the parity bits typically have been inserted into the encoded data word by different encoders, the system and method uses a rate matching algorithm to provide an optimized pattern for puncturing the parity bits so that substantially the same number of parity bits provided by each encoder are punctured.

Abstract: An approach for providing a multiple-beam antenna system for receiving and transmitting electromagnetic signals from a plurality of closely spaced satellites is disclosed. Dielectric inserts are selectively coupled to the feedhorn bodies to alter the radiation patterns according to dielectric constants of the dielectric inserts. A reflector produces multiple antenna beams based upon the altered radiation patterns of the feedhorn bodies. The antenna provides simultaneous transmissions to satellites that are spaced about 2° or less.

Abstract: An antenna alignment apparatus and alignment method is used to effectively position an antenna used in a satellite communication system on the satellite orbital arc, and to ensure that a proper antenna polarization is achieved during installation or alignment of a remote station antenna. The apparatus includes a secondary receiving device mounted on the feed arm of the antenna at a specified distance from the primary receiving device located on the primary plane of the antenna. An antenna using this system and method may be properly aligned on the orbital arc using only simple receiving equipment.

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: 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 waveguide and a method for assembling the same are provided. The waveguide comprises a first half and a second half. A gasket is applied to a first mating surface of the first half. The first mating surface of the first half is aligned with a second mating surface of the second half. The gasket is positioned between the first mating surface of the first half and the second mating surface of the second half. The first half is fastened to the second half to form the assembled waveguide.

Abstract: Space-time codes for use with layered architectures with arbitrary numbers of antennas are provided such as rate k/n convolutional codes (e.g., rates higher than or equal to 1/n where n is the number of transmit antennas). Convolutional codes for layered space-time architectures are generated using matrices over the ring F[[D]] of formal power series in variable D.

Abstract: A method and apparatus for broadcasting newsgroup information to a plurality of users uses a news server, which is in communication with the Internet, a newscast transmitter, a satellite gateway, and a subscriber station. The news server gathers newsgroup information from Internet newsgroups, and the newscast transmitter, in conjunction with the satellite gateway and a satellite, distributes all of the information to a plurality of subscriber stations. The subscriber stations preferably include personal computers equipped to receive broadcast newsgroup information. The subscriber stations each include a personal news server, storage media and a newsreader. The personal news server filters newsgroup information received based on subscription information stored only local to the receiver. The filtered newsgroup information is stored on the storage media for use at a later time when a user desires to read the newsgroup information.

Abstract: An improved system and method for performing lossless data compression of a data string by parsing the data string and representing the parsed characters of the data string as irreducible grammar that is efficiently updatable. The system and method are each capable of parsing the data string into a least one variable of irreducible grammar, such that each variable represents a respective plurality of data characters of the data string, and formatting each variable of irreducible grammar as a linked list data structure having at least one pointer pointing to a linked list data structure representing another variable. The system and method are each further capable of updating the irreducible grammar based on at least one character to be parsed in the input string by changing at least one pointer of at least one of the linked list data structures to point to a linked list data structure different than that to which the at least one pointer pointed prior to updating.

Abstract: A system and method for pointing a non-tracking antenna in a geo-synchronous satellite-based communication system is provided. A satellite terminal antenna is initially pointed towards the target satellite by any desired method. The antenna bore sight is then aligned towards the center of a satellite station-keeping box for operational use. By pointing the antenna bore sight towards the center of the satellite station-keeping box, the largest excursion between the antenna's bore sight and the actual satellite position is no greater than half the diagonal of the satellite station-keeping box despite the fact that satellite will move within the satellite station-keeping box's outer limits after the installation of the non-tracking antenna.

Abstract: A system and method of blind channel estimation to receive a signal burst over a communications channel; divide the signal burst into a prescribed number of groups of symbols; hypothesize all possible transmitted data sequences or each group; generate a corresponding channel estimate for each possible data sequence; determine an error measurement for each corresponding channel estimate; select a number of the corresponding channel estimates for each group from amongst the corresponding channel estimates, the number of the corresponding channel estimates being selected for having smaller error measurements than remaining corresponding channel estimates not selected; identifying a best channel estimate for each group from amongst the number of the corresponding channel estimates having been selected for each group; and reviewing the best channel estimate having been identified for each group and reidentifying best channel estimates for some of the groups so as to increase smoothness of a curve in two-dimensiona

Abstract: A multiprotocol radio communications network that includes a first plurality of stationary transceivers for handling low-tier traffic and a second plurality of stationary transceivers for handling high-tier traffic. The stationary transceivers communicate information to a mobile transceiver at different information rates. A switching center automatically switches communication between the mobile transceiver and the stationary transceivers as the mobile transceiver moves between areas of different traffic density.

Abstract: A requesting terminal includes an interface that allows a user to select whether data downloaded from a network (such as the Internet) is transmitted to the requesting terminal via a high-speed link, such as a satellite link, or a lower speed link, such as a terrestrial link. Preferably, the terrestrial link (which may comprise a conventional dial-up Internet connection) is a two-way link, wherein the requesting terminal transmits data requests to the network via the terrestrial link. The data requests generated by the requesting terminal are modified to designate whether the requested data should be downloaded from the network via the terrestrial link or the satellite link. The terrestrial link may also be automatically selected for certain applications.

Abstract: A satellite telephony communication system is used to provide a method of delivering service voice announcements to remote ground transceivers in the satellite telephony system. A relatively small portion of the satellite's bandwidth is dedicated to broadcasting periodic service voice announcements. When an announcement is desired, the remote ground transceiver tunes to the announcement frequency and retrieves the desired announcement in the broadcast sequence. Preferably, the announcements are broadcast in bursts, with a control data burst repeated periodically among the announcement bursts. The control data burst notifies the ground transceiver about the location and duration of each broadcast announcement, thus allowing the transceiver to time its voice path connection to the announcement frequency such that it starts at the beginning of the desired announcement and terminates at the end of the desired announcement.

Abstract: A method and apparatus for synchronizing and error checking received bitstreams of encoded information is provided. The apparatus includes a single polynomial division shift register. The method involves calculating successive syndromes using the single polynomial division shift register by shifting the received bits of information, generating a syndrome, and comparing the syndrome to a known marker syndrome.