Abstract: A calculating method for deducing all possible scenarios of satellite members and possibilities thereof in a low earth orbiting (LEO) satellite constellation is described, which is achieved mainly by relying on the spherical geometry analysis and probabilities and statistics technologies, in an attempt to rapidly and precisely obtain the concerned scenarios and possibilities thereof observed on the earth ground. With any user-defined orbital parameters and a position of an observation station for the scenarios on the earth ground inputted, all the possible scenarios and possibilities thereof can be obtained with the calculating method.

Abstract: A satellite communication system includes a satellite earth station operably coupled to a data network, and a plurality of satellite modems, each satellite modem of the plurality of satellite modems communicating in an upstream and downstream data communication mode with the satellite earth station via at least one servicing satellite.

Abstract: A proposed spread spectrum signal receiver includes a radio front-end unit and a processing unit. The radio front-end unit, in turn, has an antenna, a digitizing circuit and a primary buffer unit. The antenna is adapted to receive radio signals (SHF) from a plurality of signal sources, and the digitizing circuit is adapted to downconvert and filter the received signals (SHF), and generate sample values (SBP-D) thereof. The primary buffer unit is adapted to temporarily store the sample values (SBP-D) from the digitizing circuit and allow the processing unit to read out a first set of stored sample values (SBP-D) contemporaneously with the storing of a second set of sample values (SBP-D) in the primary buffer unit. The processing unit is adapted to receive the sample values (SBP-D) from the primary buffer unit, and based thereon, produce position/time related data (DPT).

Abstract: Systems and methods for obtaining corrected time information in a GPS-enabled device connected to a mobile handset via a short-range wireless network, such as a Bluetooth™ Piconet™. The mobile handset includes a GPS time and a network clock synchronized with a network clock in a short-range wireless network interface in the GPS-enabled device. The GPS-enabled device may send requests for time information to the mobile handset. The mobile handset receives the request and latches the network clock time and the GPS time. The captured network clock time and GPS times are sent to the GPS-enabled device in response to the request. The GPS-enabled device subtracts the captured network clock time from its own network clock time and adds the difference to the captured GPS time to obtain a corrected GPS time.

Abstract: A system for reducing electromagnetic interference between two or more co-located antennas is described herein. In one embodiment, the system includes a first antenna for transmitting a first signal within a first frequency band, and a second antenna for operating within a second frequency band during transmission of the first signal. The first and second frequency bands may be substantially identical, or may occupy overlapping or nearby channels within the radio frequency spectrum. The system also includes an apparatus. In one embodiment, the apparatus is positioned proximate to the second antenna for intercepting the electromagnetic energy radiated from the first antenna during transmission of the first signal. In other embodiments, the apparatus may be positioned proximate to the first antenna for intercepting the electromagnetic energy radiated from the second antenna during transmission of a second signal.

Abstract: A business model of satellite digital audio broadcasting, also referred to as multicasting, teaches computer improvements in business operations for the determination of the number of listeners and listeners' preferences of multicast satellite transmissions and more particularly to the detection of signals from a multitude of individual client radios that simultaneously respond to a polling signal with a radio frequency chirp. A response to a polling signal instruction is synchronized utilizing an instruction embedded within a digital audio broadcast. Further embodiments teach a determination of listener count derived from signal strength, single chirp signal strength contribution derived from reception delay, and media prioritization derived from changes in user preferences.

Abstract: A method of transmitting subpackets in a mobile communication system using at least one frequency carrier is disclosed. More specifically, the method comprises receiving a first broadcast subpacket from a base station (BS) at a first time slot on a first frequency carrier, and receiving at least one subsequent broadcast subpacket from the BS via at least one relay station (RS) at a second time slot on a second frequency carrier, wherein information of the first broadcast subpacket and the subsequent broadcast subpacket are the same.

Abstract: Methods and apparatuses for acquiring and demodulating a data stream transmitted in a communication system. A method in accordance with the present invention comprises finding a boundary of a physical layer frame (PLFrame) in the data stream, finding a first 26 bits of a Unique Word (UW) associated with the data stream, finding a scrambling code utilizing the UW, and using a decoding procedure to determine a modulation type and code rate used for desired signals within the data stream.

Abstract: A method of flexibly allocating capacity in a satellite coverage area, comprising establishing a frequency reuse pattern of at least two interleaved sets of cells, assigning a polarization to each set of cells, such that adjacent sets of cells alternate in orthogonal polarization, flexibly assigning satellite transmit power to at least one cell, flexibly assigning frequency and bandwidth to at least one cell, and moving frequencies, bandwidths, and satellite transmit power among the cells within each set, independently of the other sets, ensuring that at all times no two adjacent cells within a given set share a common frequency.

Abstract: Techniques for allocating transmission gaps and making cell measurements in asynchronous communication networks are described. A terminal establishes communication with a first communication network (e.g., a W-CDMA network), receives an initial allocation of transmission gaps for making cell measurements, and makes measurements for cells in a second communication network (e.g., a GSM network) during the allocated transmission gaps. The terminal determines the timing of at least one cell in the second network, which is asynchronous with the first network, and sends the cell timing to the first network. The terminal then receives a new allocation of transmission gaps for making cell measurements. The locations of the transmission gaps in the new allocation are determined based on the cell timing reported by the terminal. The terminal makes measurements for the at least one cell in the second network during the transmission gaps in the new allocation.

Abstract: Methods, systems, and devices are described for synchronization in mesh satellite communications. The arrival time of the gateway signal may be used to set a start of receive frame time for a terminal. A received control signal from the gateway may then be used to set a start of transmit frame time for the user terminal. The distance between the satellite and the gateway may change. Ephemeris data, various collections of terminal measurements, or terminal sync bursts may be used to modify start of transmit frame or start of receive frame settings for the terminal or gateway.

Abstract: Methods, systems, and devices are described for synchronization in mesh satellite communications. The arrival time of the gateway signal may be used to set a start of receive frame time for a terminal. A received control signal from the gateway may then be used to set a start of transmit frame time for the user terminal. The distance between the satellite and the gateway may change. Ephemeris data, various collections of terminal measurements, or terminal sync bursts may be used to modify start of transmit frame or start of receive frame settings for the terminal or gateway.

Abstract: Methods, systems, and devices are described for synchronization in mesh satellite communications. The arrival time of the gateway signal may be used to set a start of receive frame time for a terminal. A received control signal from the gateway may then be used to set a start of transmit frame time for the user terminal. The distance between the satellite and the gateway may change. Ephemeris data, various collections of terminal measurements, or terminal sync bursts may be used to modify start of transmit frame or start of receive frame settings for the terminal or gateway.

Abstract: Disclosed is a satellite beam pointing system that uses color encoded signals from subscribers to align antennas on a satellite and to align the satellite. Subscribers detect the signal strength and signal-to-noise ratio of signals that are transmitted from the satellite. The values of the signal strength and signal-to-noise ratio data are encoded in signals that are transmitted back to a ground station that color encodes the data and graphically displays the signal strength and signal-to-noise ratio of the subscriber received signals. The actual beam projection can then be determined and the satellite antennas moved, so that the actual beam projection coincides with the intended beam projection. Also, the satellite can be properly oriented using this technique.

Abstract: A gateway node that communicates with a plurality of satellite nodes positioned on one or more logical layers is disclosed. Satellite nodes on the first logical layer operate as repeaters for nodes not on the first logical layer. The gateway node and each satellite node communicate outbound messages during a synchronized outbound communication time. Satellite nodes execute a receiving communication time that overlaps with a transmitting communication time for a satellite node on a logical layer that is one layer closer to the gateway node during the outbound communication time. The satellite nodes also communicate messages to the gateway node during a synchronized inbound communication time. Each satellite node executes a transmitting communication time that overlaps with a receiving communication time for a satellite node on a logical layer that is one layer closer to the gateway node during the inbound communication time so that messages are communicated to the gateway node.

Abstract: A satellite communications system is described for increasing capacity through spectrum reuse by multiple satellites. The system includes a constellation of satellites traveling in a geosynchronous orbit, where the geosynchronous orbit defines a ground track. The satellites operate in a first mode when traveling in a first latitudinal direction on the satellite track and in a second mode when traveling in a second latitudinal direction on the satellite track. By using different operation modes, satellites traveling in opposite latitudinal directions do not interfere with each other. Each of the satellites maintains a minimum spacing apart from other satellites moving in the same latitudinal direction to prevent interference from satellites using the same operation mode.

Abstract: Methods and apparatus are presented to facilitate the transfer of a PPP session of a mobile communication device that is handed between multiple communication networks with different air interfaces.

Abstract: A method and apparatus for adaptively transmitting an uplink signal comprising information from a ground station to a satellite is disclosed. The method comprises the steps of receiving a transmitted downlink signal at a ground station from the satellite; measuring the quality of the transmitted signal; computing a prediction of a degradation of the uplink signal using the quality of the received signal, and transmitting the uplink signal according to the predicted degradation of the uplink signal.

Abstract: Communications occur between a satellite and respective first and second classes of terminals using substantially different polarizations. The first class of terminals may include fixed and/or vehicle-based terminals, and the second class of terminals may include handheld terminals. The second class of terminals may include terminals configured to preferentially receive and/or transmit linearly polarized signals, for example, terminals with substantially linearly polarized antennas, and the first class of terminals may include terminals configured to preferentially receive and/or transmit circularly polarized signals, for example, terminals with patch and/or helical antennas configured to transmit and/or receive substantially circularly polarized signals.

Abstract: A radioterminal communications system includes an ancillary terrestrial component configured to receive from at least some of a plurality of radioterminals using frequencies from a first satellite frequency band (e.g., an L-band) and to transmit to at least some of the plurality of radioterminals using frequencies from a second satellite frequency band (e.g., an S-band). The system further includes a space-based component configured to communicate with the plurality of radioterminals using at least some of the frequencies from the first satellite frequency band and/or at least some of the frequencies from the second satellite frequency band. In some embodiments the ancillary terrestrial component communicates with radioterminals using a Time Division Duplex (TDD) mode and the space-based component communicates with the same or other radioterminals using a Frequency Division Duplex (FDD) and/or a TDD mode.

Abstract: A system and method for managing access to a satellite-based transponder by a plurality of aircraft each having a mobile radio frequency (RF) system. The system employs a ground-based, central control system for managing access to the satellite-based transponder so that the aggregate power spectral density (PSD) of the RF signals of all the mobile systems does not exceed, at any time, limits established by regulatory agencies to prevent interference between satellite systems. This is accomplished by a dual control loop arrangement for monitoring the signal-to-noise ratio (Eb/No) of the RF signal transmitted by the satellite-based transponder. A ground-based control loop is used whereby a ground-based central controller monitors the Eb/No and transmits commands to the aircraft (via the satellite transponder) to maintain the Eb/No of the transmitted signal within a predetermined range.

Abstract: A space-based component (SBC) of a communications system includes a service link subsystem including a plurality of service link antenna elements configured to provide service links with radioterminals and a feeder link subsystem configured to provide respective feeder links to/from respective processing facilities. The SBC further includes a channelizer configured to map different spectral components of a signal received at the SBC via a service link antenna element to different feeder links.

Abstract: A communication system, method, computer program product, and apparatus include common equipment shared between multiple independently administered networks. The common equipment is reconfigurable and expandable and provides changed communication capacity and functions when additional elements are added or reconfigured. Configurable features include, for example, communication bandwidth, Quality of Service, and a number of communication satellites included in the communication system. The common equipment includes expandable elements including, for example, a single hub modem chassis that can expand to communicate with more than one communication satellite and a protocol processor that can share a protocol processing task with another protocol processors.

Abstract: A satellite is linked to a number of gateways by a number of feeder links. When a degraded link is detected among the feeder links, communications are switched from the degraded link to a diversity link shared among the feeder links. In one embodiment, the diversity link is connected to a diversity gateway located outside a service area of the satellite. In another embodiment, the diversity link comprises channels distributed among the feeder links within the service area.

Abstract: In a method for relative time and position determinations for moving objects of a constellation, signals by the objects are isochronously transmitted, with each object transmitting a unique signal for that object. The received signals of each object of the constellation are transmitted to all other objects of the constellation after a predetermined waiting time.

Abstract: A two-way satellite communications system includes an Earth station communicating with a plurality of remote terminals using a network access protocol that facilitates low power consumption by the terminals. The earth station generates forward link TDM packet data transmissions on one or more satellite channels, and detects, despreads and decodes multiple concurrent return link slotted CDMA packet transmissions on one or more satellite channels. It communicates through a wired connection with a packet processing center which ultimately both delivers return link packet data to end-customers and receives forward link packet data from end-customers. The remote terminals receive, process and act upon forward link TDM transmissions on one or more satellite channels, and generate slotted spread spectrum CDMA transmissions on the return link on one or more satellite channels.

Abstract: A wireless terminal using OFDM signaling supporting both terrestrial and satellite base station connectivity operates using conventional access probe signaling in a first mode of operation to establish a timing synchronized wireless link with a terrestrial base station. In a second mode of operation, used to establish a timing synchronized wireless link with a satellite base station, a slightly modified access protocol is employed. The round trip signaling time and timing ambiguity between a wireless terminal and a satellite base station is substantially greater than with a terrestrial base station. The modified access protocol uses coding of access probe signals to uniquely identify a superslot index within a beaconslot. The modified protocol uses multiple access probes with different timing offsets to further resolve timing ambiguity and allows the satellite base station access monitoring interval to remain small in duration.

Abstract: The transportation system, such as airplane, which comprises the internal wireless communicating system and the external antenna system. The passenger(s) in the transportation system may access network (e.g., the Internet) via the internal wireless communicating system and the external antenna system. The transportation system further provides security measure.

Abstract: A communication satellite comprises at least one antenna configured to communicate with at least one ground terminal over a first communication link in a first frequency band and a second communication link in a second frequency band. The first communication link and the second communication link are for communicating the same information. A satellite communication system comprises a first satellite having a first antenna configured to communicate with a ground terminal over a first communication link in a first frequency band and a second communication link in a second frequency band. The satellite communication system further comprises a second satellite having a second antenna configured to communicate with the ground terminal over a third communication link in the first frequency band and a fourth communication link in the second frequency band. The first communication link and the second communication link are for communicating the same information.

Abstract: The invention refers to a satellite communications system with a mobile user terminal. In order to provide a satellite communications system which enables communication with a mobile user terminal via conventional communication satellites on any area of interest on earth, a quasi-geostationary satellite is operated in an inclined orbit and sends a spread downlink signal s? (t) to said area of interest on earth to be received and despreaded by a mobile user terminal.

Abstract: The invention relates to a method of synchronizing a mobile station with a base station in a wireless communications system, to a mobile station for a wireless communications system, as well as to a wireless communications system of this kind. In order to enable faster ultimate synchronization, it is proposed to compare components of the received data not only with a stored synchronization pattern, but also with a stored identification pattern prior to the adaptation of the timing of the mobile station to received data. Already before the synchronization it can thus be determined with a high degree of probability whether received data originates from a desired base station or not. The necessity of checking the contents of packets which are not associated with a desired base station can thus be avoided.

Abstract: A method and system for a plurality of airplanes in flight to receive from and send to a plurality of ground stations broadcast and communication signals through a single or a plurality of geostationary satellites, wherein at least the mobile link between said airplanes and said satellite, uplink or downlink, uses the high frequency radio waves at 17 GHz or higher, such as Ka-band. The fixed link between said satellite and said ground stations may use any radio frequencies below the frequencies used to communicate between the satellite and the aircraft. The lower frequencies tend to be less susceptible to rain attenuation and hence suitable for closing the fixed broadcast and communication link. Frequencies such as C-band or Ku-band, or even Ka-band, are applied between satellite and ground such that the available link margin is sufficient to overcome rain attenuation at said ground stations.

Abstract: A system and method for communicating between ground stations and mobile satellites effectively eliminates the need for transferring information from one ground station to another. Communication between a ground station and a mobile satellite is accomplished via an intermediate network of geosynchronous control satellites. The mobile satellite is positioned within a three-dimensional cellular grid formed by the network of geosynchronous satellites. This system is particularly applicable to a terrestrial network communicatively coupled to the geosynchronous network via one or more ground stations. The terrestrial network of ground stations no longer needs to perform expensive, time-consuming and manual synchronization and hand-off procedures.

Abstract: A system for communicating data among a plurality of ships is disclosed. The system comprises means for sending an inbound message from one of said plurality ships (501), via at least one geostationary satellite (503) and base station (505) to a control center (507). Spatial information obtained from the control messages is consolidated by the control center (507) to reduce traffic volume of outbound messages associated with inbound messages. Consolidated messages are then sent via base station (505) and at least one geostationary satellite (503), to a sub-set of said plurality of ships, wherein sub-set of ships are in at least one of the same (a) geographic region, and (b) adjacent region(s), as said one ship.

Abstract: A communications system, apparatus, method, and computer program product for inter-satellite and inter-spacecraft crosslinks (ISL) with non-ISL optimized antennas on spacecraft. The system includes a mobile communications platform that includes an ISL antenna configured to transmit information to a target satellite through a non-ISL antenna of the target satellite. The mobile communications platform is configured to relay transmissions through the non-ISL antenna of the target satellite to another communications platform. The mobile communications platform includes a controller configured to determine a location of the mobile platform; determine whether the target satellite is within communications range; and prepare a signal for relayed transmissions through a non-ISL antenna of the target satellite to another communications platform in a signal format that is decipherable by this other communications platform.

Abstract: A satellite radiotelephone frequency band can be reused terrestrially by an ancillary terrestrial network even within the same satellite cell, using interference reduction/cancellation techniques. An interference reducer is responsive to a space-based component and to an ancillary terrestrial network. The interference reducer is configured to reduce interference in wireless communications that are received by the space-based component from first radiotelephones in the satellite footprint over a satellite radiotelephone frequency band using wireless communications that are received by the ancillary terrestrial network from selected ones of second radiotelephones in the satellite footprint over the satellite radiotelephone frequency band and/or wireless communications that are transmitted by the ancillary terrestrial network to the second radiotelephones in the satellite footprint over the satellite radiotelephone frequency band.

Abstract: The invention discloses a method that implements synchronization for a WCDMA system. The method introduces a globe synchronization time to the WCDMA system as a reference time for signal transmitting of all NodeBs; when searching adjacent cells or making handover, each UE takes this reference time as a reference time; in this way, the UE design complexity is reduced, the UE available time is increased, the handover signaling is simplified and the handover success and reliability are increased too. Therefore, the method increases system capacity and makes service quality better.

Abstract: The present invention relates to a method of synchronizing base stations of a terrestrial cellular communication system using a satellite component.

Abstract: In base station 100, TA control amount calculating section 106 calculates a time alignment control amount based on a signal received from communication terminal station 150. Then, TA control amount rounding section 107 performs rounding on the time alignment control amount to obtain a time aliment control amount of the predetermined number of significant digits and a rounding error amount. Reception timing correcting section 109 corrects the reception timing detected in reception timing detecting section 103, using the rounding error amount. Receiving section 104 obtains demodulated data from a received signal at the corrected reception timing.

Abstract: A receiver includes a tuner and a circuit. The tuner receives an indication of a radio frequency signal from an antenna feedline in response to the radio frequency signal being provided to the antenna feedline by an amplifier. The circuit transmits a control signal to the antenna feedline to control a gain of the amplifier in response to a strength of the radio frequency signal.

Abstract: A low profile mobile in-motion antenna and transmit/receive terminal system for two-way “VSAT” type satellite communication using FSS service, preferably in Ku band, supporting at the same time TV signal reception from the same satellite or a separate DBS satellite located at the same or nearby geo-stationary orbital position.

Abstract: A satellite system includes a plurality of orbit slots having a first orbital and a second orbital slot. A first satellite occupies a first orbital slot and generates a first set of uniform beams. A second satellite located in a second orbital slot generates a second set of uniform beams. A tiling pattern on the face of the Earth has a plurality of cells, with each of the cells having a defined frequency for communication. The first set of beams and the second set of beams are generated according to parameters to avoid interference between them. The parameters may include satellite orbit separations, beam size, multiplicity of band reuse, and ground station received beamwidth.

Abstract: A method of communicating with a transceiver (120). In one arrangement, the method of communicating with the transceiver can be performed in a systemless group environment. Synchronization information (150) can be received from a mobile transceiver (110) and used to synchronize to the mobile transceiver. The synchronization information can include a timing offset and a frequency offset. Synchronization can be maintained until a predetermined condition is met, for example, a predetermined amount of group inactivity.

Abstract: A system, method, apparatus, means, and computer program code for improving accuracy of radio timing measurements. According to some embodiments, a wireless terminal or other wireless device can make adjustments to a measurement made from a radio transmission source by adjusting timing measurements using a weighted average and/or synchronizing its timing to the timing of this or some other radio transmission source. The adjusted measurements can be obtained for times other than when the original measurements are made. Measurements for multiple radio transmission sources can then be adjusted to a common time wherein adjustment errors due to unknown timing drift in the radio sources and wireless terminal and Doppler errors due to unknown relative velocities can be reduced or eliminated.

Abstract: A UWB repeater preferably applied to a relay of stream data, which does not require frequency conversion and has less delay in relay. The UWB repeater includes a receiving antenna, a receiver, a transmitter, a transmitting antenna, and a relay controller. The relay controller is provided with a switch unit, a delay, and a transmitting/receiving timing controller. UWB pulse signals demodulated by the receiver are power-amplified by the transmitter and transmitted after being delayed by the delay unit for timing that does not overlap the receiving timing. The transmitting/receiving timing controller turns on the switch unit during the period of pulse receiving timing and enables a relay of the receiving pulses, and turns off the switch unit during the period of relaying of pulses, and can prevent sneak path signals between the transmitting side and the receiving side.

Abstract: A method is disclosed for establishing communication links in a satellite based wireless communication system. The method includes: establishing a forward link from the satellite to at least one of a plurality of subscriber wireless communication devices (WCDs) by use of a shared frequency multi-user communication protocol; applying an error correction code to use in the forward link, whereby the error correction applies to an aggregation of communications provided to multiple ones of the WCDs; and receiving communications in a return: link signal by use of a protocol providing channels having dedicated frequency assignments and non-slotted channel assignment.

Abstract: A first radio signal is received via a first satellite reception path, for example, an antenna or spot beam, which serves a satellite cell. The received first radio signal includes a desired satellite uplink signal transmitted from a first source using a frequency assigned to the satellite cell and an interfering signal transmitted from at least one second source using the frequency assigned to the satellite cell. A second radio signal is received via a second satellite reception path, for example, via another antenna or spot beam of the system and/or via a satellite antenna beam of another system. The second radio signal includes a measure of the interfering signal. The first and second radio signals are processed to recover the desired satellite uplink signal.

Abstract: A mobile terminal generates an estimate of GPS time. The mobile terminal includes a cellular receiver, a GPS receiver, and a processor. The cellular receiver is configured to receive communication signals from cells in a wireless communication system. The GPS receiver receives GPS signals and determines a GPS time reference therefrom. The processor estimates a cell time reference from the received communication signals, and generates cell-to-GPS timing data that represents a time offset between the cell time reference and the GPS time reference. The processor then estimates GPS time based on a time indicator portion of a received communication signal and the cell-to-GPS timing data. The estimated GPS time may be used by the GPS receiver to acquire GPS signals.

Abstract: A communication system has a stratospheric platform with a payload controller and a phased array antenna having a plurality of main array elements for generating a plurality of communication beams and a plurality of auxiliary elements for canceling interference between the communication beam. A gateway station communicates with the stratospheric platform. The gateway station scales the plurality of elements to form a reconfigurable plurality of beams. The gateway station communicates an embedded control signal to the stratospheric platform to communicate a scaling of elements to form the communication beams and the auxiliary element output. The auxiliary element output is used to provide interference canceling.

Abstract: Methods and an arrangement for synchronizing communication of framed data via asynchronous base stations (BS1, BS2) in a cellular communication system are presented. The synchronization methods are performed continuously by sending out certain system frame counter states from a central node in the system to all its connected base stations (BS1, BS2). Each base station (BS1, BS2) includes a local frame counter (LFCBS1, LFCBS2), which generates local frame counter states (t1(1)-t1(4), t2(1)-t2(4)) correlated to the system frame counter states. Transmission of information via the base stations (BS1, BS2) is synchronized by assigning each data frame (DR(1)-DR(4)) a particular frame number, which is given by the local frame counter states (t1(1)-t1(4), t2(1)-t2(4)), so that data framed (DF(1)-DF (4)) having identical numbers contain copies of a certain data packet.