1727 results about "Satellite communication systems" 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.

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 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.

Two satellite communications systems can use the same frequency or frequencies in geographically overlapping footprints, without creating undue interference in a given system that is caused by the same frequency signal(s) that is / are used by the other system. In particular, an aggregate Effective Isotropic Radiated Power (EIRP) of the radioterminals and / or ancillary terrestrial components of a second satellite communications system in the common footprint is sufficiently low, and / or the receive antenna gain of a first satellite communications system is sufficiently low compared to the receive antenna gain of the second satellite communications system, so as to increase an aggregate receiver noise that is seen by the first satellite system receivers by an amount that does not substantially change a Quality of Service (QoS) of the first satellite communications system.

A method and apparatus for mitigating communications interference between satellite communications systems in different orbits is disclosed. The method comprises the steps of evaluating a geometrical relationship between a second ground station and the satellites in the second satellite constellation, and directing communications between the second ground station and the second satellite according to the evaluated geometrical relationship. In one embodiment communications are handed over from a first satellite to another satellite when the first satellite is no longer at the highest elevation angle of visible satellites. In another embodiment, handover occurs when the first satellite drops below a minimum elevation angle.

A satellite communication system includes a plurality of satellites, such as low earth orbit satellites, and a plurality of gateways. The satellite communication system is bidirectionally coupled to a terrestrial communication system through at least the plurality of gateways. The satellite communication system and the terrestrial communications system together form a data communication network having a plurality of nodes including source nodes, destination nodes and intermediate nodes. Multiple copies of a packet can coexist within the data communication network, and the packet and its one or more copies are routed, using at least in part satellite-resident routers and gateway-resident routers, over a plurality of different paths between a particular source node and a particular destination node. At least one duplicate copy of a given packet is simply not used during the execution of a packet reordering procedure in the destination node, or at an intermediate node. Certain of the paths are carried over satellite-to-satellite cross-links, while certain other ones of the paths are carried over satellite-to-gateway uplinks and downlinks, and at least one path exists between a user terminal and at least one satellite. In a preferred embodiment the packets are TCP / IP (or equivalent protocol) packets containing information for enabling the selective destruction of a duplicate packet to occur.

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.

An approach is provided for supporting retrieval of web content over a meshed communication network. A first server receives a request from a browser application for the content resident in the web server. The first server includes a downstream proxy configured to modify the request to include information specifying support of a parse and pre-fetch service within an optional header field of the request as to permit handling of the modified request by the web server in absence of an upstream proxy that is communicating with the web server. A second server is configured as the upstream proxy to intercept the modified request and pre-fetch the content from the web server. The second server forwards the pre-fetched content over the communication network to the first server. This approach as particular applicability in relatively high latency networks, such as a satellite communications system.

A satellite communication system including an interface device for distributing satellite signals received from an outdoor unit (ODU) to a plurality of indoor units (IDUs) connected to a local area network (LAN), at a particular site. Only two cables, a power cable and a cable connected to the LAN, must be installed between the interface device and the site containing the IDUs. Accordingly, the installation of IDUs at a site is simplified and has the flexibility of allowing future satellite based services to be added without requiring the installation of new cables between the ODU and the IDUs. The satellite communication system also permit flexibility among connected devices, including to which other devices they are connected, how they are connected to other devices and what types of connections are used.

The present invention relates to an electromagnetic wave transmission / reception source for a multireflector antenna of the Cassegrain type comprising longitudinal-radiation means operating in a first frequency band and an array of n radiating elements of the travelling-wave type operating in a second frequency band with the n radiating elements arranged symmetrically around the longitudinal-radiation means, the array and the longitudinal-radiation means having an approximately common phase centre, the array of n radiating elements being excited by a waveguide of polygonal cross section. The invention applies especially in satellite communication systems operating in the C-, Ku- or Ka-bands.

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.

A compact, agile polarization diversity, multiple frequency band antenna with integrated electronics for terrestrial terminal use in satellite communications systems is disclosed. The antenna includes an antenna feed having highly integrated microwave electronics that are mechanically and electromagnetically coupled thereto in a distributed arrangement so that diverse polarization senses having a low axial ratio and electronic switching control of the polarization senses is provided. The arrangement of the integrated distributed transceiver configuration enables the mechanical rotation of the orientation of a first transceiver for skew alignment while a second transceiver remains stationary relative to the antenna feed assembly. The first transceiver can be a high-band transmitter and receiver pair that supports linear polarization senses and the second transceiver can be a low-band transmitter and receiver pair that supports circular polarization senses. The antenna system presented is highly compact and offers improved polarization performance previously achievable by only larger devices.

A high-speed, low-complexity Reed-Solomon (RS) decoder architecture using a novel pipelined recursive Modified Euclidean (PrME) algorithm block for very high-speed optical communications is provided. The RS decoder features a low-complexity Key Equation Solver using a PrME algorithm block. The recursive structure enables the low-complexity PrME algorithm block to be implemented. Pipelining and parallelizing allow the inputs to be received at very high fiber optic rates, and outputs to be delivered at correspondingly high rates with minimum delay. An 80-Gb / s RS decoder architecture using 0.13-μm CMOS technology in a supply voltage of 1.2 V is disclosed that features a core gate count of 393 K and operates at a clock rate of 625 MHz. The RS decoder has a wide range of applications, including fiber optic telecommunication applications, hard drive or disk controller applications, computational storage system applications, CD or DVD controller applications, fiber optic systems, router systems, wireless communication systems, cellular telephone systems, microwave link systems, satellite communication systems, digital television systems, networking systems, high-speed modems and the like.

The present invention makes it possible to precisely monitor remotely located objects. The construction vehicles each contain a GPS apparatus, and various sensors for capturing the states of vehicle parts, and are capable of reporting, as required, the current position captured by the GPS apparatus, and operation information captured by the various sensors to the TMS mail server via the satellite communication system. The TMS mail server and the rental company system are capable of communicating at any time via a communication network between computers. The TMS mail server collects the latest positional information, operation information, and so forth, on the construction vehicles being rented and relays such information in the form of electronic mail, for example, to the rental company system as required or periodically. The rental company system displays construction vehicles by means of marks in the current positions of the construction vehicles on a map represented by map data, or in the form of a list, based on the collected positional information and operation information, on a branch store computer terminal. The system also displays the operating states of rented construction vehicles based on the collected operation information, on the branch store computer terminal.

Systems and methods are described for paired-beam satellite communications in a flexible satellite architecture. Embodiments include one or more “bent pipe” satellites having multiple transponders for servicing a number of spot beams. Implementations include novel types of paired-beam transponders that communicatively couple gateway terminals and user terminals in different spot beams. Some implementations also include loopback transponders that communicatively couple gateway terminals and user terminals in the same spot beam. The transponders can use similar components, can provide for flexible forward-link and return-link spectrum allocation, and / or can provide other features. Certain embodiments further include support for utility gateway terminal service and / or redundancy (e.g., active spares) for one or more active components.

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.

An aircraft monitoring system adapted for mounting in an aircraft and at a location independent of the aircraft for providing information related to aircraft location and / or the current state of the operation of the aircraft. The monitoring system includes an aircraft-tracking device and a server computer adapted for communicating with an aircraft owner / operator. The device includes a signal receiving antenna for receiving signals from a satellite positioning system and a decoder connected to the antenna for decoding the location position coordinates (GPS or GLONASS). Further, the aircraft-tracking device includes a microprocessor connected to the decoder and a two-way satellite communication transceiver. The transceiver is connected to a two-way radio communication antenna. The radio communication antenna receives and sends two-way satellite communications between a satellite communication system. The satellite communication system communicates with a ground-based satellite communication service. The server computer is connected to the satellite communication service and is connected to a telecommunication system for alerting the owner / operator as to the aircraft's location and / or the current state of operation.

A border gateway protocol (BGP) management system (10) dynamically determines an optimum or preferred data route (12) from wireline networks (18) into a satellite communication system (11). Multiple gateways (16, 30-34) provide access points to the wireline networks. The management system includes a connectivity matrix which processes (74) information, such as bandwidth availability and route congestion, and then generate a BGP update that is communicated (80) into at least one of the gateways. The BGP update promotes preferred gateways and so identifies a preferred access path to the satellite system. Specifically, the BGP update instruction contains a metric altering a weighting of an identified route data route, which metric effects path selection at a gateway receiving IP datagrams. The metric is derived from information pertaining to a connectivity matrix associated with the satellite system.

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.

A method for implementing an activity based resource assignment medium access control (MAC) protocol to allocate resources to subscribers in an interactive, multimedia, broadband satellite communications system. A plurality of channels is provided with at least one of said plurality of channels being assigned to each of a plurality of terminals. Utilization of the channel resources by the plurality of terminals is monitored and an evaluation is conducted of system needs based on the levels of activity and utilization of channel resources by the terminals. Requests for system resources by the terminals are communicated to a resource controller which calculates the system needs. The resource controller is utilized to adjust the channel resources based on the levels of activity and utilization of resources by the terminals. The adjustment provides active terminals as much resources as required during duration of their activity, subject to resource availability.

An approach is provided for providing quality of service reservations in a packet-based radio communication network is disclosed. Connection information including connection rate is extracted from a dataflow from an application requesting connection-oriented service. A request message is sent to a proxy for establishing a connection based on the connection information over the network, wherein the proxy configures a classification rule based on flow criteria from the request message and accordingly initiates establishment of the connection over the network to a destination terminal. A confirmation that the connection can be established is selectively received according to the connection information, wherein the dataflow satisfying the flow criteria from the application is transported over the established connection to the destination terminal. This approach as particular applicability to shared capacity systems, such as a satellite communication system.

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.

A method and apparatus (system) for providing forward-link channel-frequency allocation for multiple-satellite cellular communications networks is disclosed. The system has a centralized ground-operations control center that provides bi-weekly minute-by-minute allocation plans for geographically-defined service areas. This enables each service area to set its diversity policy in accordance with the requirements of the government regulators and customer preferences within the service area. The system has a user model having a frequency re-use pattern, a channel allocation model for modelling the power allocated to each channel, and a gateway channel model for allocating channels in accordance with the user model and the channel allocation model. The allocation is made for each satellite of the plurality of satellites. The traffic allocation induces an operating frequency for each of the one or more links in each satellite of the plurality of satellites. The satellite communication system computed frequency allocation is optimized to minimize total radiation from all forward links for one or more of the plurality of satellites.

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 two-way satellite communication system is disclosed. A transceiver transmit signals over a return channel to a satellite and receives signals over a downlink channel from the satellite. A hub communicates with the transceiver over the return channel, wherein the hub provides connectivity between the transceiver and a packet switched network.