2540 results about "Satellite Telecommunications" patented technology

The present invention relates to Random Access Channel (RACH) access apparatus for mobile satellite communication system and method therefor. The method for accessing random access channel (RACH) on satellite system, random access channel (RACH) carrying message from a plurality of mobile stations to the satellite system, the method includes the steps of: receiving preamble and the message, the message successively transmitted with the preamble from the plurality of mobile stations; and transmitting acquisition response signal corresponding to the preamble or the message to the plurality of mobile stations. Accordingly, success of packet reception of satellite system is improved and transmission delay is reduced.

The present invention relates to one- or two-way Direct-To-Home (DTH) satellite communications systems which broadcast high bit rate wideband television and multimedia content to user terminals located within a desired coverage area and, more specifically, a single or multi-transponder Direct-To-Home satellite communications system in which a high bit rate wideband data stream is comprised of real-time, statistically multiplexed information and non-real-time information that is transmitted to a subscriber media gateway device for storage and later-use. The user terminal contains a specially designed receiving system and may contain a transmitter for transmission of a return data channel to the Broadcast Center.

First radio signals are received by a first satellite, the received first radio signals including a desired satellite uplink signal transmitted from a first source using a frequency assigned to the first source and an interfering signal transmitted from a second source using the frequency assigned to the first source. The first radio signals are combined based on a first performance criterion to generate a first output signal. Second radio signals are received by a second satellite, the received second radio signals including a measure of the desired signal. The second radio signals are combined based on a second performance criterion to produce a second output signal. The first and second output signals are combined to generate an estimate of the desired satellite uplink signal.

The invention provides apparatus and methods for monitoring and controlling hydrocarbon production wells and / or injection wells from a remote location. The apparatus for monitoring and controlling one or more hydrocarbon production wells or injection wells from a remote location comprises one or more surface control and data acquisition systems; one or more sensors disposed in communication with the one or more control and data acquisition systems; one or more downhole flow control devices disposed in communication with the one or more control and data acquisition systems; and one or more remote controllers disposed in communication with the one or more control and data acquisition systems. Preferably, the remote controller comprises a computer having an internet access disposed in communication with the one or more control and data acquisition systems through a communication device comprising an internet web site server. The method for monitoring and controlling a downhole hydrocarbon production well or an injection well comprises: transmitting data collected by a downhole sensor module to a control and data acquisition system; evaluating downhole operating conditions and optimizing downhole operating parameters utilizing an optimization software program disposed in communication with the control and data acquisition system; and transmitting signals between the control and data acquisition system system and a remote controller utilizing a satellite communication system, the remote controller comprising a computer and an internet browser control access adapted to display operating conditions and parameters and to accept instructions to change operating parameters.

The invention discloses a circular polarized antenna with a wide wave beam width and a small size. The antenna comprises a square paster; two notch grooves of an open circuit of a terminal are arranged on the square paster, wherein the two notch grooves are mutually orthogonal; the paster is fixed on a square grounding reflecting surface by a coaxial line. And four short-circuit columns of the open circuit of the terminal are arranged on the reflecting surface, so that the size of the reflecting surface is reduced. According to the invention, a signal feeding technology is utilized to excite the two orthogonal notch grooves to work in a circular polarization mode. According to the invention, an impedance bandwidth reaches 19%, wherein a standing-wave ratio is less than 2; and a 3d axial ratio bandwidth reaches 3.8%. In an axial ratio bandwidth, a 3d B wave beam width reaches a value by adding 101.4 degrees with 1.4 degrees or subtracting the 1.4 degrees from the 101.4 degrees as well as a gain reaches a value by adding 5.76dBi with 0.18dBi or subtracting the 0.18dBi from the 5.76dBi. The circular polarized antenna has advantages of compact antenna dimension, light weight, low cost and easy manufacture. Especially, the circular polarized antenna has advantages of good impedance bandwidth, wide radiation wave beam, and high gain. Therefore, the circular polarized antenna can be widely applied to satellite communication and traffic navigation.

The present invention provides a multiple band mobile radio (also referred to as a Wireless Communication Device (WCD)) capable of communicating with both a satellite communication system and a terrestrial communication system. The satellite communication system can be, for example, a Low Earth Orbit (LEO) satellite system. The terrestrial communication system can be a Personal Communication System (PCS), or a cellular system, including either an analog or a digitally based cellular system. The cellular analog system can be AMPS. The digitally based cellular system can be a CDMA or a TDMA based communication system. The WCD can concurrently receive signals from the terrestrial communication system and the satellite communication system.

An apparatus and method for paging a user terminal (UT) using a satellite communications system having a gateway and one or more satellites, wherein each satellite produces a plurality of beams and each beam includes a plurality of channels. The method of the present invention includes the step of recalling a location of the UT, wherein the recalled location corresponds to a location of the UT at a time t1. In one embodiment this is accomplished by performing a lookup in a table that includes location information for user terminals at different points in time. The method also includes the step of determining an area, based on the recalled location, within which the UT is assumed to be located at a time t2, where time t2 is later in time than time t1. The next step is to determine a time t3, where t3 is equal to or later in time than time t2, when the following two criteria are satisfied. First a satellite of the one or more satellites has an elevation angle between theta1 and theta2. Second, all locations within the area are located within a footprint of the satellite (that has an elevation angle between theta1 and theta2). The elevation angles theta1 and theta2 can be determined from the perspective of the recalled location. Alternatively, the elevation angle can be determined from the perspective of all locations within the area. This ensures that the UT is in the "sweet spot" of the satellite (where the gain of signals sent from the satellite are highest) when the UT is paged. A page is then sent from the gateway to the UT on a channel of a beam of the satellite at time t3. The page can be sent on a channel of every beam of a plurality of beams that make up the footprint of the satellite at time t3. Alternatively, the page can be sent on a channel of selected beams of the footprint. By waiting until the UT is within the "sweet spot" to page the UT, less power can be used by the satellite. In addition, this type of operation allows the UT to use an antenna that has a substantial gain only when the UT is within the "sweet spot". This allows the use of satellite power to be reduced further.

The present invention provides a multiple band mobile radio (also referred to as a Wireless Communication Device (WCD)) capable of communicating with both a satellite communication system and a terrestrial communication system. The satellite communication system can be a Low Earth Orbit (LEO) satellite communication system. The terrestrial communication system can be a Personal Communication System (PCS), or a cellular system, including either an analog or a digitally based cellular system. The WCD can concurrently receive signals from the terrestrial communication system and the satellite communication system. Also, the WCD can receive signals useful for position location, such as a GPS satellite signal alone, or both GPS and satellite communication signals, simultaneously.

An antenna system includes a beamformer having a feed port and a one-dimensional or two-dimensional arrangement of output ports, radiating antenna elements coupled with output ports of the beamformer, and an antenna control unit coupled with the beamformer to steer a beam of the antenna system. The antenna system forms an electrically steerable, phased array antenna having a beam steering angle which is constant over a very broad band of frequencies. Specific applications for the antenna system include satellite communications including tracking low earth orbiting satellites, radar systems and data links using a steerable antenna for self-installation, self-healing and adaptation.

A signal power control loop is provided for a link between a terrestrial station and a terminal when the terminal and a satellite are linked via the terrestrial station. The signal power control loop may control transmitted signal power of the terminal and / or the terrestrial station. In some embodiments, the signal power control loop controls transmitted signal power of the terminal and / or the terrestrial station independent of signal power control for a link between the terrestrial station and the satellite.

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.

An object locator device is disclosed for use in conjunction with both a GPS satellite system and a two-way communication satellite. The object locating system includes a mobile unit physically connected to the object to be located. The mobile unit includes a satellite communication transceiver capable of receiving and transmitting encoded signals. A decoder is associated with the satellite communication transceiver for decoding a unique signal associated with that mobile unit and for generating an activation signal upon receipt of the unique signal. The mobile unit further includes a GPS receiver which is activated in response to the receipt of the unique signal so that the GPS receiver generates a position signal representative of the position of the mobile unit. The output signal from the GPS receiver is connected as an input signal to the satellite communication transceiver such that the satellite communication transceiver transmits the.position signal to a base station on the communication satellite. The base station physically separated from the remote unit is operable to both transmit the unique signal to the communication satellite in order to activate the mobile unit as well as for receiving the position signal from the communication satellite following activation. The base station creates a display representative of the location of the mobile unit. Preferably, this display signal is transmitted via a telephone line and modem to a computer which generates the display on a computer monitor. Energy conservation algorithms including periodic activation of the satellite communication transceiver as well as activation of the satellite communication transceiver only when the position of the mobile unit has changed more than a threshold amount between periodic signals is disclosed.

A system and method of free-space optical satellite communications includes a ground station and transceiver for transmitting and receiving an optical communications signal. Adaptive optics at the ground station are operative with the transceiver for determining the shape of any distortions in the wavefront of the optical communications signal and compensating at the ground station for the distortions. A satellite includes a transceiver for transmitting and receiving the optical communications signal and includes adaptive optics for determining the shape of any distortions in the waveform of the optical communications signal and compensating at the satellite for the distortions.

Communications are conducted between a space-based component of the wireless communications system and radioterminals using a plurality of forward link cells and a plurality of return link cells, the return link cells having a greater number of cells per frequency reuse cluster than the forward link cells. At least some of the forward and return link cells may use at least some frequencies of a terrestrial wireless communications system having an adjacent and / or overlapping coverage area. Forward links of the at least some of the forward and return link cells may have a greater link bandwidth than return links of the at least some of the forward and return link cells.

A system designs a thin and relatively flat microwave focusing lens that can produce multiple simultaneous beams, using readily-available isotropic dielectric materials, and having a gradient-index (GRIN) profile. The design optimizes the lens to achieve beam scanning and / or multiple beams over a wide field of regard (FOR) with broad bandwidth and a very short focal length compared with conventional lenses. The lens can be used individually or as an element in a more complex antenna having multiple lenses in various orientations that are independently switched, selected and / or excited simultaneously as elements in a phased array. The antenna terminal incorporates such lens into an array of lenses along with one or more feeds to produce single or multiple beams covering a broad field of regard for such applications as satellite communications on-the-move, cellular, broadband point-point or point-multipoint and other terrestrial or satellite communications systems. The lens and array design support multiple simultaneous independently steerable beams as well as null placement for interference cancellation.

A hybrid satellite communications system provides communications, particularly Internet access, to computer users. The hybrid satellite communications system includes a satellite system and a terrestrial communications system. The satellite system includes two transceivers. The first transceiver receives and transmits a first set of signals received from the terrestrial communications system to a plurality of user units. In reverse fashion, the satellite systems second transceiver receives a second set of signals in a second frequency band from the user units and transmits those signals back to the terrestrial communications system. The first set of signals (downlink signals) are of much higher frequency than the second set of signals (uplink signals). Preferably, the first set of signals are relayed by a Direct Broadcast System (DBS) satellite in a frequency band between 12.2 GHz and 12.9 GHz, while the second set of signals are relayed by a Mobile Satellite System (MSS) satellite operating between 1.0 GHz and 3.0 Ghz, or relayed by a terrestrial node operating between 0.8 and 2.0 Ghz. The differences in frequency between the first set of signals and second set of signals is considered optimal for the transmission and receipt of communications between a computer user with the Internet. Moreover, the present invention is capable of using the present communications infrastructures dedicated to the satellite transmission of television via DBS satellites, satellite cellular communications via MSS satellites, and radio communications via terrestrial cellular systems.

Antenna and satellite communications assemblies and associated satellite tracking systems that may include a low profile two-way antenna arrangement, tracking systems, and applications thereof. Applications for the system include military, civilian, and domestic emergency response applications. The antenna arrangements may be configured to form a spatial multi-element array able to track a satellite in an elevation plane by electronically dynamically targeting the antenna arrangement and / or mechanically dynamically rotating the antenna arrangements about transverse axes giving rise to generation of respective elevation angles and dynamically changing the respective distances between the axes whilst maintaining a predefined relationship between said distances and the respective elevation angles. The system provides autonomous dynamic tracking of satellite signals and can be used for satellite communications on moving vehicles in a variety of frequency bands for military and civilian applications.

The invention relates to mobile communication systems using wireless network cells inside a vehicle, such as an aircraft, other airborne vessel, ship or train while aboard, and using satellite communications between the cells inside the vehicle and the terrestrial communication system. According to the invention there is an emulator functionality provided at both ends of the satellite communication link. The emulator is capable of providing required state signalling without a connection between the base station and the base station controller, and therefore the satellite communication link can be switched to off state when it is not needed for transferring calls or other information. The invention also provides a possibility to use alternative satellite connections depending on the location of the vehicle.

A data recording unit 60 for managing operating situations of a hydraulic excavator 1 comprises a RAM 67 for taking in and storing plural kinds of operational information regarding the hydraulic excavator 1 as operational data, and a CPU 65 for extracting top priority operational data from among the plural kinds of operational data stored in the RAM 67, and transmitting the extracted data to the supervising side via satellite communication. Top priority data among the plural kinds of operational data of the hydraulic excavator, which may bring the hydraulic excavator into rest, can be presented to a supervisor of the hydraulic excavator, etc.

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. The remote terminals communicate with a local digital data source and / or sink, digitize one or more local analog sensor signals, enter into a sleep mode to minimize the terminal's power consumption, and access the satellite communications network in accordance with the system network access protocol.

A mobile communications system transporting messages between mobile terminals and a central control center using a satellite communications system. The central control center and the mobile terminals each store a plurality of message display forms each having a form identifier and a predetermimed display format. The message display forms are selected as templates for generating user messages including message data supplied at the originating station. The satellite messages transmit the user message by transmitting the message data and the form identifier of the corresponding selected message display form. The receiving station, upon receiving the satellite message, accesses the message display form from memory in response to the supplied form identifier, and combines the accessed message display form with the message data to recreate the user message. The mobile terminals are designed as low-cost data terminals requiring a minimum amount of memory. The mobile terminals include a satellite transceiver, a graphic user interface providing a display and accepting key inputs from the user, and a software system including an application layer providing all messaging functions for the user and a middleware layer controlling transport of messages between the application layer and the satellite transceiver. The application layer operates as an event-based state machine, and includes an event handler that controls the application layer operations in accordance with the processing capacity of the middleware layer.

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.

A system for determining at least one of uplink ASI and downlink ASI in a satellite communication system having at least a first satellite and a second satellite, each having uplink and downlink footprints and being in communication with respective earth stations and having a potential interference. The system comprises a first antenna for receiving downlink signals communicated from said first satellite, a second antenna for receiving downlink signals communicated from said second satellite, power spectrum measurement equipment connected to the second antenna for measuring the second satellite power spectrum, and CSM equipment connected to the first antenna and the power spectrum measurement equipment for generating an adjacent satellite carrier plan.

A distributed digital communications network and method for interactive communications, e.g., for cellular, wireless Internet access, digital television, and / or like multimedia services, is provided, that includes one or more global communications satellites positioned and adapted for receiving and relaying packet data communications encapsulating the interactive communications. One or more base station(s) are located in each of a plurality of selected remote geographic regions, and have mobile wireless links to a plurality of subscribers of communications services in the region. A plurality of satellite communications terminals is also provided for communicating with the satellite from the region. Each terminal is located in the selected remote geographic region and associated with one or more of the base stations. In addition, a plurality of user terminals are utilized, each located in the selected remote geographic region and associated with the base station(s) in the region. One or more base station controller(s) located remotely from, or locally with, the base station(s) have programming for controlling the base stations. Furthermore, a single mobile switching center located remotely from, or locally with, the base station controller(s) and the base stations. The switching center, in addition, has a digital communications signal processor for handling digital signal switching between the plurality of base stations, and / or wireline and / or other communications network(s). Finally, a packet data network is utilized between the satellite and satellite communications terminals for interactive data communications throughout the distributed network.

A system and method for increasing the performance of a satellite communication system by using a multivariate analysis approach to optimize the pointing of the boresight of a satellite-mounted antenna. Optimizing the pointing of the boresight of the antenna minimizes sidelobe generation, and thus Co-Channel Interference (CCI) in geographic areas served by the system. By minimizing CCI, the overall system performance of the communication system is optimized. To optimize the pointing of the boresight of the antenna, the overall performance of the satellite communication system is determined, and the boresight of the antenna is iteratively repointed in the direction of increasing system performance until the optimized boresight pointing is determined. Alternatively, the frequency re-use plan of the satellite communication system may be analyzed to determine a high density cell region and the boresight may be pointed to the high density cell region.

A communications system and method are disclosed that may include a constellation of satellites operating in a substantially equatorial, non-geostationary orbit; a plurality of ground stations configured to communicate with the satellites, at least one given ground station of the ground stations lacking a wired connection to any global communications network; and at least one gateway station coupled to a global communications network and to at least one said satellite, wherein each satellite includes at least one antenna having a steerable beam, the antenna being controllable to continuously direct a concentrated spot beam toward the given ground station.

A satellite communication system is disclosed which provides multiple beams and employs a plurality of user terminals (UT) and at least one gateway connected to a PSTN which communicates with at least one UT over the system wherein each of the UTs within a given frequency band is distinguished one from the other employing a combination of time slots and orthogonal codes.

An approach for processing packets for transmission over a satellite communications network is disclosed. A communication system includes a satellite terminal that provides connectivity for a host. The satellite terminal includes a user interface that receives a packet associated with an application from the host, and classification logic that classifies the packet into one of a plurality of transport services based upon the corresponding application. The satellite terminal also includes a mapping logic that maps the one transport service to one of a plurality of packet delivery services, wherein the one packet delivery service provides transmission of the packet to the satellite. The system also includes a hub that is configured to communicate with the satellite terminal over the satellite to provide the plurality of packet delivery services.