2476 results about "Satellite Telecommunications" patented technology

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 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.

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 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.

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.

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.

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 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 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 emergency satellite communications system that provides remote sites with assured access. The network is provisioned, configured, and managed such that the remote units are always online, but not used to an extent that would prevent remote units from communicating via the network upon demand. The network may include geographic hub diversity to protect against hub failure. Proactive monitoring of the components comprising the network is used to mitigate or prevent network congestion, such as by load balancing. An overflow link may be provided, allowing for remote sites to be assigned from a first link to the overflow link to mitigate or prevent congestion on the first link, and/or allow for additional bandwidth to be allocated to one or more remote sites that remain on the first link. A satellite communication network may comprise a satellite and a network management system operative in controlling and managing a plurality of first and second terminals. A first earth station may be communicatively coupled to one or more terrestrial communications networks, where the first earth station provides a first communication link via the satellite for bidirectional communication between the first earth station and the plurality of first terminals assigned to the first earth station by the network management system. A second earth station may be geographically diverse from the first earth station and is communicatively coupled to at least one terrestrial communications network. The second earth station may provide a second communication link via the satellite for bidirectional communication between the second earth station and the plurality of second terminals assigned to the second earth station by the network management system.

A satellite communications system (10) includes a hub (14), a satellite (32), and any number of remote terminals (16). Each remote terminal (16) includes a remote receiver (38), a monitor (40), and a network access controller (42). Each remote receiver (38) is configured to receive and down convert the system's entire spectrum of interest from which channels are accessed by the remote terminals (16). The monitors (40) independently perform FFT processes over this entire spectrum, but at a low frequency resolution which is no higher than needed to distinguish channels. Based on these spectral analyses, uplink/inbound channels are independently selected by the network access controllers (42) at each remote terminal (16). Remote terminals (16) immediately transmit data to the hub (14) as soon as they select an uplink/inbound channel.

A satellite communication subscriber device includes a smart antenna for generating antenna beams for receiving signals from at least one satellite, and a receiver. The receiver includes a quality metric module for calculating a quality metric on the signals received by each antenna beam. A beam selector is coupled to the smart antenna for selecting the antenna beams. An antenna steering algorithm module runs an antenna steering algorithm for operating the beam selector for scanning the antenna beams, receiving the calculated quality metrics from the receiver for each scanned antenna beam, and comparing the calculated quality metrics. The algorithm selects one of the scanned antenna beams based upon the comparing for continuing to receive signals from the at least one satellite.