Abstract: The present invention concerns a telecommunication network for establishing radiofrequency links between at least one gateway and ground terminals via a multispot telecommunication satellite. The network includes a service zone composed of a plurality of cells each including a plurality of ground terminals, the said service zone being split into N sub-zones, N being an integer strictly greater than 1, each sub-zone having a capacity profile evolving in time over a given period and presenting a maximum value, the said maximum values of each of the capacities being shifted with regard to time and a multispot satellite including a transponder including amplification of the signals emitted by the gateway on the forward link and the signals emitted by the cells on the return link and a continuous power supply system of the amplifier.

Abstract: A method and system for dynamically triggering re-connection of a TDMA-capable radio to a TDMA-based talk group via a TDMA site. The dynamic re-connection is triggered by the group call controller when an initial request for connection to the TDMA-based talk group is made through an FDMA site by the TDMA-capable radio.

Abstract: A shared wireless channel may serve real-time traffic and non-real-time traffic. Depending on channel conditions, the real-time traffic may experience variable levels of quality. The present invention contemplates systems and methods for guaranteeing bounded access time for real-time applications in a shared wireless network in the presence of non-real-time traffic. The systems and methods provide mechanisms to adapt to changing characteristics of wireless channels and to maximize throughput of non-real-time traffic while preserving the quality of real-time applications. The systems and methods may be extended generally to provide adaptive control over the delivery of multiple classes of traffic to protect the quality of critical applications over a shared transmission medium, including IEEE 802.11 networks, IEEE 802.16 networks, and DOCSIS networks.

Abstract: A serial multiplexer module for server management includes a first, a second and a third switching devices in circuit connection with a baseboard management controller, a serial transceiver and an input/output controller respectively. Each of the switching devices includes respectively four simplex sub-switches. The simplex sub-switches are controlled to be switched on/off directly/indirectly by a first control signal and/or a second control signal transmitted from the baseboard management controller, thereby enabling and monitoring the communication between the baseboard management controller, the input/output controller and the serial transceiver.

Abstract: Methods for propagating a network topology model of a binary tree topology network through a network, the network including a root node and leaf nodes, networked together to provide a communications path for data, each of the nodes except the root node being docked downtree of a parent node, and each of the nodes docked uptree of a first child node and a second child node, each of the at least one leaf nodes having none of the plurality of nodes docked downtree of and therewith. Each of the leaf nodes provides a propagate network topology model message containing the address of the providing leaf node to the parent node docked uptree of and with the providing leaf node. Each node receiving the message forms a network topology model representing a path from the receiving node to each one of the plurality of nodes downtree of the receiving node.

Abstract: Embodiments of the present invention relate to communication systems. Such communication systems may include a beamformer that is adapted to provide a plurality of beams, each of the plurality of beams providing communication for a corresponding coverage envelope, the plurality of coverage envelopes comprising at least one pair of overlapping coverage envelopes and at least one pair of non-overlapping coverage envelopes, and a scheduler that assigns system resources from a group of shared system resources to a plurality of receivers distributed throughout the coverage envelopes, the scheduler being adapted to assign the same system resources from the group of shared system resources for use during a simultaneous data transmission to a receiver in each of the coverage envelopes that comprises the at least one pair of non-overlapping coverage envelopes.

Abstract: In one embodiment, a system for data handling in a distributed communication network includes one or more data-handling nodes (DHNs) that each reside at one of one or more receptors. Each receptor is operable to receive first data units from one or more remote units. Each DHN is operable to extract second data units from the first data units, add extensions to the second data units for tracking the second data units in the distributed communication network, store the second data units locally at the receptor, generate log files of the second data units for communication to a data monitoring and recovery (DMR) agent at the receptor, and communicate the second data units with the added extensions to a routing system for routing the second data units in the distributed communication network.

Abstract: A inter-station transmission method of extending time allocated for a transmission path delay of an inter-station transmission path within a predetermined turnaround time, and increasing an inter-station transmission distance. A radio base station reproduces a clock synchronized with a BSU transmission clock DCLK used when transmitting downlink transmission data from a communication control station. The radio base station processes the downlink transmission data. The clock synchronization eliminates a necessity of data format conversion between the communication control station and the radio base station, a buffer accumulating transmission data in preparation for the conversion is not necessary. This reduces a turnaround time of a mobile communication system.

Abstract: A low-cost, low-power, low-complexity, small, high-reliability, robust, seamless satellite communication network is described. The network performs encoding of a user signal at the customer premises to enable routing of the user signal to an appropriate destination beam at the satellite requiring low power user signal processing. Routing information is embedded at the periphery of the network CPE's rather than at the satellite. Embedding the routing information in this way greatly reduces on-board switching complexity and increases signal to interference ratio for the user.

Abstract: A method and system for determining attenuation and controlling uplink power in a satellite communication system includes receiving a beacon signal and establishing a clear sky uplink power value. A fade value is determined in response to the beacon signal and in response to the clear sky uplink power value and the fade value, an uplink power is determined. The fade value corresponds to a delta value in addition to the clear sky uplink power to obtain the final uplink power.

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 wireless base station that performs data communication using a plurality of sub carriers, and repeatedly generates frame patterns comprising one combination or more of at least two types of frames in which the number of common pilots in each is different, and transmits data for mobile terminals having poor receiving quality in a frame having a large number of common pilots, and transmits data for mobile terminals having good receiving quality in a frame having a small number of common pilots.

Abstract: A data switching system for a satellite in a satellite data transmission system which relays from a terrestrial sending area to a terrestrial receiving area via the satellite data including payload data and associated control data which constitutes respective switching requests and provides data on the switching of the payload data. The system analyzes data on the basis of a signal conveying the control data and switches the payload data as a function of the result of the analysis of the associated control data to at least one of a plurality of sending ports for sending it to the receiving area. Only the control data is analyzed. The payload data is not analyzed.

Abstract: An arrangement for providing synchronization between a number of overlapping area access points within a wireless LAN utilizes a Power over Ethernet (PoE) cable connection to transmit synchronization signals from a centralized hub/switch to each of the access points connected to the cable. The synchronization signal takes the form of a direct sequence spread spectrum (DS-SS) signal that is coupled onto the twisted pair used to provide the low voltage PoE signal to various powered devices. At each access point, a filter is used to remove the synchronization signal from the PoE transport, allowing for the group of access points to share a common beacon signal and allow for frequency re-use among the access points. The DS-SS signal is preferable created by a combination of a baseband signal and a set of separate pseudo noise (PN) sequences defining a precision phase (“pilot tone”) signal, a time mark (superframe/beacon) signal, and a time-of-day (real-time clock) signal.

Abstract: The invention relates to a method for transmitting signals in a radio communication system consisting of at least two frequency signal-transmitting channels. At least the first (fcoord) of said frequency channels is used for organizing radio resources, and at least the second (fi) of the frequency channels is used for transmitting signals between the stations of the system where the signal transmission is carried out by the frequency channels from/in a direction of said stations in conformity with a predefined temporal pattern (P1, P2, P3).

Abstract: A method for relaying data packets to a subscriber station (SS) by taking a relay station (RS) into consideration when a base station (BS) establishes a data packet scheduling is disclosed. According to the method, a data packet is relayed by RSs, which have a signal intensity greater than a threshold value for all RSs appointed by the BS. Each SS determines whether the SS receives the data packet directly from the BS or via an RS, based on signal intensities between the SS and the BS and between the SS and RSs, and feeds channel information corresponding to the determination back to the BS, thereby allowing the data packet to be transmitted.

Abstract: A method and apparatus for wireless communication in which groups of expected mobile device mobility speed ranges are established. A first sub-carrier block arrangement for the group having the lowest expected mobility speed range is determined. The first sub-carrier block arrangement is comprised of a plurality of sub-carriers. A second sub-carrier block arrangement for a group having an expected mobility speed range faster than the expected speed range of the lowest expected speed range group is determined. The second sub-carrier block arrangement is comprised of the plurality of sub-carriers. The first and second sub-carrier block arrangements are different but use the same sub-carrier spacing and symbol duration.

Abstract: Time division multiplexed input signals (i.e., separated into time slots) are spread in each time slot with a destination code. This spreading is applied for destination identification as opposed to signal information modulation. Each spreading signal is associated with a particular destination for a particular time slot. These spread signals are then combined on a code division bus. Output signals for retransmission to the destinations are recovered from the bus by application of despreading codes. Each despread signal has a destination code which appears in its individual time slot. In a variant code division multiplexed signals are directed to a destination by use of time slot interchanger to achieve time division switching to route the CDMA multiplexed channels.

Abstract: A method and system for communicating a facsimile (fax) message over a computer network. A user initiates the sending of the fax to a recipient fax transceiver located outside the user's local-toll area of a Public Switched Telephone Network (PSTN). A first fax transceiver transmits the fax to a first server, wherein the first fax transceiver and the first server both are located in the same local-toll area. The first server then transmits the fax via the Internet to a second server, which is located in the same local-toll area as the recipient fax transceiver. The second server, having an inbound, dial-up access modem pool, is configured to process and transmit the fax via the local PSTN to the recipient fax transceiver.

Abstract: A system and methods for wireless computing devices to become mesh member nodes within a self-configuring mesh network includes mechanisms for neighbor discovery and sharing of a common topology database including mesh topology and mesh network information. Each mesh node may use the topology database to determine optimized routing paths within the mesh network. Mesh member nodes are configured to detect and communicate topology changes and measured mesh network attributes to other members of the self-configuring wireless network.

Abstract: A method and system for determining delays between a primary site and a diverse site in a satellite communication system includes uplinking signal from the primary site and the diverse site. A controller determines a switchover processing time, a communication time between the primary site and the diverse site and a gap time to establish a gap at the receiving device. The controller changes uplinking from the primary site to the diverse site in response to the switchover processing time, the communication time and the gap time.

Abstract: A mode switching method in a mobile communication system is provided. The method comprises providing a mode switching start point between an uplink signal and a downlink signal of a transceiver; resetting the mode switching start point based on length of a guard period provided between the uplink signal and the downlink signal; and starting mode switching at the mode switching start point.

Abstract: A partial mesh link channel is established within a satellite communication system by allocating return link channel resources to the partial mesh link channel.

Abstract: A system and method for propagating a network topology model of a binary tree topology network through the network. The network includes a plurality of nodes, including a root node and at least one leaf node, operatively networked together. Each leaf node provides a propagate network topology model message to the parent node docked uptree of and with the providing leaf node. Each of the plurality of nodes that receives the propagate network topology model message forms a network topology model representing one or more paths from the receiving node to nodes downtree of the receiving node, stores the model in a memory accessible to the receiving node, and provides a propagate network topology model message containing the network topology model to the parent node docked uptree of and with the receiving node. A network topology model is thereby propagated through the network.

Abstract: An apparatus and method for synchronizing the transmission of uplink signals and reception of downlink signals by a terminal in a mobile communication system is disclosed, the apparatus and method allowing a terminal to adaptively compensate for deflection generated in synchronization of a transmission channel and a fine adjustment to be made for controlling channel synchronization. A new switching point between uplink time slots and downlink time slots is determined based on a detected present switching point and a recognized uplink and downlink time slot construction, with the new switching point utilized to perform switching between a receiver and transmitter with a variable time interval. A delay may be inserted in a transmitted uplink signal to compensate for errors in the switching function.

Abstract: An adaptive MIMO communications system includes a multifunctional reconfigurable antenna with a selectively alterable effective physical antenna array configuration and radiation/polarization properties, which configuration and properties is a component in the optimization of the adaptive system parameters. The multifunctional reconfigurable antenna comprises a plurality of antenna components and a plurality of selectively controllable switches coupling selected ones of the plurality of antenna components together into a multifunctional reconfigurable subarray of antenna components. A processing unit coupled to the multifunctional reconfigurable antenna determines communication channel conditions for generating adaptive control signals to the plurality of selectively controllable switches to selectively apply a selected space-time coding protocol or a selected beam forming protocol together on the plurality of antenna components depending on channel conditions.

Abstract: A low-cost, low-power, low-complexity, small, high-reliability, robust, seamless satellite communication network is described. The network performs encoding of a user signal at the customer premises to enable routing of the user signal to an appropriate destination beam at the satellite requiring low power user signal processing. Routing information is embedded at the periphery of the network CPE's rather than at the satellite. Embedding the routing information in this way greatly reduces on-board switching complexity and increases signal to interference ratio for the user.

Abstract: An adaptive controller for linearization of transmitters using predistortion of the input signal has reduced sensitivity to impairments such as gain variation, phase noise or modulation/demodulation frequency instability by linearizing an adaptively normalized gain provided through a separate estimation and cancellation of linear gain variations. Values of a nonlinear and a linear gain blocks, cascaded with the linearized transmitter and called respectively a predistortion block and a gain regulation block, are independently adjusted by two different adaptive controllers. In one embodiment, four banks of real gain elements compose the predistortion block and realize an arbitrary step-wise approximation of a generalized 2×2 transmit gain matrix of nonlinear functions. In a further embodiment cancellation of a DC level bias multi-channel impairment is provided by an adaptively adjusted signal adder inserted in the transmit chain between the predistortion block and the linearized transmitter.

Abstract: Systems and methods for transmitting and receiving diverse signals across regions using a minimum of frequency capacity and maintaining compatibility with the heritage system. A system of the invention comprises at least one broadcast transmitter for transmitting a broadcast signal in a first frequency band to a receiver, at least one gapfiller transmitter for transmitting a gapfiller signal in a second frequency band to the receiver and at least one set of reuse transmitters for transmitting a plurality of spotbeam signals in the first frequency band to define coverage regions and at least one coverage gap where the spotbeam signals are not transmitted. A method of the invention comprises receiving a first signal, receiving a second signal, generating a first intermediate frequency (IF) signal from the first signal, generating a second IF signal from the second signal, filtering the second IF signal to produce a filtered second IF signal and combining the filtered second IF signal and the first IF signal.

Abstract: A set of formats and protocols is proposed for a satellite communications system. In these formats, a pilot signal (PS) is inserted after every 25 or 29 data symbols. The formats consist of SCPC frames (F) which may contain either data (D) and in-band signaling information (SU), or only signaling information (SU). In either case, the contents of each frame (F) are error-correction coded before transmission with the same coding rate. Each data frame (F) carries the data content of an integral number of input user data frames (M), each of which comprises four subframes. Different symbol transmission rates are used for different input data rates, the symbol transmission rates being selected so that their different synchronizing clock rates can easily be obtained from a common clock. Data bursts may be preceded by a constant power level preamble (P). The formats and protocols satisfy the requirements of a high data rate satellite communications system.

Abstract: A communications payload configuration comprising a multi-port amplifier that incorporates remotely controllable travelling wave tube amplifiers (TWTAs) for allowing their output power to be adjusted depending on the traffic demand and the payload operational conditions. The power delivered by each TWTA is controlled by adjusting the TWTA anode voltage in response to a command signal received from the ground station. If a TWTA fails, the power delivered by each of the remaining TWTAs is increased by gross anode voltage control. The power lost by the failure is thus recovered by increasing the power of the remaining TWTAs. This power control is done in a constant efficiency way by also readjusting the TWTA collector voltages.

Abstract: A source selection system for a communication switch for selecting a primary datasource from a plurality of datasources is provided. The system includes a validation module associated with the plurality of datasources adapted to monitor each datasource of the plurality of datasources for transmission errors in output originating from each datasource and adapted to provide information relating to the transmission errors. The system also includes a source selector associated with the validation module and the plurality of datasources, the source selector adapted to select an output datasource from the plurality of datasources. The system further includes an assessment module associated with the validation module adapted to identify the primary datasource from the plurality of datasources utilizing the information provided by the validation module and adapted to cause the source selector to select the output datasource associated with the primary datasource.

Abstract: 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.

Abstract: A satellite constellation has a plurality of satellites. Each of the satellites has an RF ground link for communicating with a ground station and an optical link for communication with at least one of the plurality of satellites. Each of the satellites has a reconfigurable optical transmitter for sending and receiving data streams. Each reconfigurable optical transmitter has a first optical carrier associated therewith and a reconfigurable optical receiver. The plurality of satellites is arranged to have a first subset of satellites. The first subset of satellites is configured to communicate. The plurality of satellites is reconfigured to have a second subset of satellites having at least one different satellites than that of said first subset. The second subset supercedes the first subset. The second subset of satellites is configured to communicate. Various subset around the globe may form local area networks. The local area networks are preferably optically coupled to form a wide area network.

Abstract: The invention is a system for distributing content data over a computer network and a method of arranging receiver nodes in a computer network such that the capacity of the server is effectively multiplied many times over, and may even be increased exponentially. The invention takes advantage of the excess capacity many receiver nodes possess, and uses them as repeaters. The distribution system includes nodes having databases which indicate their ancestors and descendants so that reconfiguration of the distribution network may be accomplished without burdening the system's primary server.

Abstract: This disclosure describes a method to generate large numbers of spot beams for multiple-beam satellite systems using smaller apertures. This is done by dividing the basic spot beam that has 3 to 4 dB of gain drop within the beam into a number of smaller 1-dB sub-beams. This has the effect of reducing the required peak gain for the antenna by 2–3 dB, thus reducing its size by as much as 50%. The frequency band allocated to the basic beam will be divided among the sub-beams. However, the frequency re-use among the basic beams can be maintained. Frequency allocations have to be coordinated among all beams. This concept is especially applicable to phased arrays using digital beam formers. The DBF complexity is a function of the number of array elements, and is less dependent on the number of beams. Reducing the array size, and consequently reducing the number of elements helps in reducing the complexity, power and mass of the DBF.

Abstract: A low-cost, low-power, low-complexity, small, high-reliability, robust, seamless satellite communication network is described. The network performs encoding of a user signal at the customer premises to enable routing of the user signal to an appropriate destination beam at the satellite requiring low power user signal processing. Routing information is embedded at the periphery of the network CPE's rather than at the satellite. Embedding the routing information in this way greatly reduces on-board switching complexity and increases signal to interference ratio for the user.

Abstract: A multimode transmission system using TDMA provides a plurality of satellite services to a ground station terminal. These services include timing beacon synchronization, multi-cast/broadcast data service, calibration data, and point-to-point data service. The multimode transmission system uses a TDM switch to generate a TDMA signal having a plurality of TDMA transmission frames. Each TDMA transmission frame includes a plurality of downlink frame time slots. Each time slot may be of variable length and is dynamically allocated to an individual satellite service based upon demand. The TDMA signal is then broadcast using an advanced transmit antenna system, which requires beam-shaping and beam power control features, to enable TDMA switching between shaped beams and spot beam modes of the antenna. These antenna features allow for the dynamic partitioning of satellite system capacity between wide-area broadcasts and localized point-to-point service and efficient utilization of the satellite transmission power.

Abstract: Time division multiplexed input signals (i.e., separated into time slots) are spread in each time slot with a destination code. This spreading is applied for destination identification as opposed to signal information modulation. Each spreading signal is associated with a particular destination for a particular time slot. These spread signals are then combined on a code division bus. Output signals for retransmission to the destinations are recovered from the bus by application of despreading codes. Each despread signal has a destination code which appears in its individual time slot. In a variant code division multiplexed signals are directed to a destination by use of time slot interchanger to achieve time division switching to route the CDMA multiplexed channels.

Abstract: A data routing subsystem (200) for a communication satellite includes an inbound module (602) that accepts demodulated uplink data. The inbound module (602) includes a routing table (702) that stores queue tags (714) specifying downlink beam hop locations (302, 304) for the uplink data. The subsystem (200) also includes a self addressed packet switch (608) having an input port coupled to the inbound module (602), and an outbound module (610) coupled to an output port of the switch (608). A memory (804) in the outbound module (610) stores the uplink data in accordance with the downlink beam hop locations (302, 304). A multiple beam array antenna (116–122) is coupled to the outbound module (610). The multiple beam array antenna (116-122) includes a first feed element (116) assigned to a first downlink beam hop location (302) and a second feed element (118) assigned to a second downlink beam hop location (304).

Abstract: A spot beam satellite communications system and method for delivering information to user terminals at a high data rate. In a hub, a high data rate serial data stream is separated into parallel data streams that are modulated onto respective uplink transponders. The uplink transponders are transmitted by the hub to an earth-orbiting satellite, which translates the uplink signals to downlink frequencies. The satellite broadcasts the transponders to user terminals located in the desired beam coverage areas on the earth. The user terminal separates the downlink transponders and demodulates each of the downlink transponder signals to regenerate the parallel data streams. The parallel data streams are combined to reproduce the original serial data stream. By dedicating multiple transponders to a particular data stream, data can be relayed at a very high data rate by a communications satellite that employs a standard transponder frequency assignment scheme.

Abstract: In a communication system with a bandwidth-on-demand processor, which may be power limited and connected to a myriad of terminals via relatively long delay paths, and another processor, which is connected to a few terminals via relatively short delay paths, an approach for effectively coordinating the processors is disclosed. A bandwidth controller receives a message requesting bandwidth from a remote processor and selectively grants the bandwidth request. The bandwidth controller transmits an assignment message that specifies a bandwidth allocation to the remote processor, and concurrently transmits a control message. A switch is configured to forward the assignment message to the remote processor. A controller is coupled to the switch and is configured to receive the control message, wherein the control message provides bandwidth allocation. The above arrangement has particular applicability to a satellite communications system.

Abstract: An improved technique for networking multiple users for retrieving data information from various data sources provides a less costly method for retrieving information while aboard a transportation vehicle, such as, for example, an aircraft. The data communications system may be carried out in one form by a data communications system having a data source, a server/router coupled to the data source and adapted to request data information from the data source, and an information distribution system coupled to the server/router and adapted to receive the data information requested from the data source.

Abstract: The system comprises transmitters transmitting programs or multimedia data to a satellite, each program being transmitted on an uplink frequency channel, and program multiplexing means onboard the satellite receiving programs and routing them onto a single downlink frequency channel. A configuration station on the ground comprises means for transmitting system data on an uplink frequency channel and configuration means onboard the satellite selectively associate uplink frequency channels and a downlink frequency channel in response to some of the received system data.

Abstract: A method and apparatus for implementing multicast in a space-based communication system is disclosed. The present invention allows for the use of a buffer in which to store data packets prior to replication in a multicast application. The present apparatus includes a buffer (102), a header memory (103), and an ASIC (101) to store and extract received data packets and replicate them as required. The ASIC (101) includes a switch interface (201), a queue manager (203), a header processor (205), a holding buffer (207), and a arbitration interface (209). The switch interface (201) is connected to the queue manager (203). The queue manager (203) is connected to the buffer (102), the header processor 205, the holding buffer (207), and the arbitration and switch interface (204). The header processor (205) is connected to the header memory (103).

Abstract: A space-based network router architecture (20) is disclosed. The router includes an array-of-processors architecture (20) for routing uplink and downlink traffic of a communications system (10). The architecture comprises multiple node interface chips (26) linked to one another via horizontal and vertical rings (22, 24), thus forming a mesh (21). Associated with each node interface chip (26) is a processor (28) and either a demodulator (30) or modulator (32). Each node interface chip (26) selectively transfers a signal depending upon the particular signal's destination and processing requirements. The router architecture (20) provides scalabitly, fault-tolerance and flexibility, as well as structural advantages over present router systems.

Abstract: A downlink orderwire integrator (63) and separator (81) for use in a processing satellite (12) and a user terminal (14) in a satellite based communications system (10) is provided having a formatter (64), a cell switch (72) and a cell sieve (80). The formatter (64) generates orderwire cells (54) with each orderwire cell (54) having a header (60) and a body (62). The cell switch (72) receives the orderwire cells (54) from the formatter (64) and traffic cells (56) from at least one uplink (16) and arranges the orderwire cells (54) and the traffic cells (52) in at least one frame (48) to transmit on at least one downlink (18). The frame (48) includes a fixed custom frame portion (42) and a fixed traffic portion (50) that contains both the traffic cells (52) and the orderwire cells (54).

Abstract: The methods (300, 900, and 1200), and apparatus (140 and 800) of the present invention employ demand assigned spatial multiplexing in a satellite communication system (100) to efficiently accommodate varying demand for high data rate service while minimizing satellite antenna and radio system complexity in a ubiquitous coverage satellite system optimized for transporting packet data. In a preferred embodiment, the methods (300, 900, 1000 and 1200) and apparatus (140 and 800) of the present invention use a first set of signaling beams (210) to establish signaling uplinks and then direct traffic spot beams (220) at particular UE devices to support traffic uplinks in accordance with demand assigned multiple access (DAMA) parameters when and only when the UE devices have traffic data to transmit to a satellite.

Abstract: A satellite communication system having a spatial segment comprising at least one satellite, preferably in a geostationary orbit, carrying a multi-beam telecommunication payload and a terrestrial segment comprising access gateways to terrestrial networks each arranged to communicate with the satellite via a forward link uplink beam and a return link downlink beam and user terminals each arranged to communicate with a satellite via a forward link downlink beam and a return link uplink beam, wherein the forward link carries signals multiplexed in time and the return link carries signals multiplexed in frequency and time, the payload comprising; a forward link router for routing signals multiplexed in time from a forward link uplink beam on a frame basis to a forward downlink beam, a return link router for routing signals multiplexed in frequency and time from a return uplink beam on a frequency bank basis to a return link downlink beam, and a mesh communication router for receiving signals multiplexed in freque

Abstract: A method in which incoming RF signals to a given node of a wireless network are detected in real-time by using a comparison circuit for comparing a signal which is indicative of the strength of an incoming RF signal with a prescribed threshold level. The output of the comparison circuit is coupled to an input of the digital signal processor (e.g., microprocessor) of the node. The microprocessor is preferably programmed to check this input prior to attempting to transmit data thus minimizing the chances of a collision occuring due to overlapping data transmitting and receiving operations. Preferably, the prescribed threshold level utilized in the comparison circuit of a given node can be selectively varied in order to thereby selectively vary the size of the cell in which the given node resides. In this connection, the neighborhood or cell sizes in which the individual nodes in the network reside are preferably adaptively varied in such a manner as to maximize the data throughput of the entire network.