Abstract: A quadrifilar helix antenna used to transmit and receive wireless signals may include a number of inductively loaded antenna elements. The antenna elements may be helically wound around a cylindrical structure.

Abstract: A node may include a receiver configured to receive signals transmitted from a gateway and a logic device coupled to the receiver. The node may also include a memory configured to store label information identifying a data packet stored in the node. The logic device may be configured to receive a message from the gateway, where the message includes label information, and access the memory to identify a data packet based on the label information included in the message. The node may also include a transmitter configured to transmit the data packet to the gateway over a channel shared with a number of other nodes.

Abstract: A node may include a receiver configured to receive signals transmitted from a gateway and a logic device coupled to the receiver. The node may also include a memory configured to store label information identifying a data packet stored in the node. The logic device may be configured to receive a message from the gateway, where the message includes label information, and access the memory to identify a data packet based on the label information included in the message. The node may also include a transmitter configured to transmit the data packet to the gateway over a channel shared with a number of other nodes.

Abstract: A system for communications on an extraterrestrial body may include a space-based component and an ancillary extraterrestrial component on the extraterrestrial body. The space-based component may be configured to provide wireless communications with a plurality of radioterminals located on the extraterrestrial body over a satellite frequency band wherein the space-based component includes at least one satellite orbiting the extraterrestrial body. The ancillary extraterrestrial component may be configured to provide wireless communications with the plurality of radioterminals located on the extraterrestrial body. Moreover, the ancillary extraterrestrial component may reuse at least one satellite frequency of the satellite frequency band, and the space-based component and the ancillary extraterrestrial component may be configured to relay communications therebetween. Related methods are also discussed.

Abstract: A quadrifilar helix antenna used to transmit and receive wireless signals may include a number of inductively loaded antenna elements. The antenna elements may be helically wound around a cylindrical structure.

Abstract: Information content is nonidentically mapped between service link carriers and feeder link carriers at a cellular satellite. A reduced number of satellite feeder link carriers compared to the number of satellite service link carriers and/or a reduced total bandwidth of the satellite feeder link carriers compared to the satellite service link carriers thereby may be obtained.

Abstract: A system and method of operation for efficiently reusing and/or sharing at least a portion of the frequency spectrum between a first satellite spot beam and a second satellite spot beam, and/or an underlay terrestrial network associated with a second satellite spot beam. The spectrum is efficiently reused and/or shared between respective spot beams and/or associated underlay terrestrial systems in a manner minimizes interference between the respective satellite and terrestrial systems.

Abstract: A satellite communications system includes a satellite that is configured to wirelessly communicate with radioterminals in a satellite coverage area over a satellite frequency band, and an ancillary terrestrial component that is configured to wirelessly communicate with radioterminals in the satellite coverage area over at least some of the satellite frequency band, to thereby terrestrially reuse at least some of the satellite frequency band. Wireless communications with a radioterminal are handed over from the ancillary terrestrial component to the satellite if the radioterminal transmit power exceeds a threshold, and a received satellite signal quality exceeds a threshold, even though the radioterminal is able to wirelessly communicate with the ancillary terrestrial component.

Abstract: A cellular communications system comprising a space based system comprising a first set of cells, and a ground based system comprising a second set of cells. The space and ground systems can optionally function substantially autonomously, with each using spectrum from at least one predetermined frequency band.

Abstract: A satellite gateway is coupled to a communications network and is operative to communicate with a communications satellite. A terrestrial terminal interface subsystem is operative to communicate with the satellite gateway via the communications satellite using a first radio interface and to communicate with terminals over a geographic area using a second radio interface. The communications network may be a wireless communications network, and the satellite gateway is configured to communicate with a base station controller of the wireless communications network, such that the terrestrial terminal interface subsystem may provide one or more satellite-linked terrestrial base stations.

Abstract: In a mobile satellite system, a system for providing satellite communication between multiple users in a closed user group arrangement includes first and second mobile earth terminals (METs) responsively connecter to and registering with the mobile satellite system. The first MET selects a closed user group network identifier (NET. ID) representing a NET group including the first and second METs to establish voice communication therewith and transmits the NET ID to a central controller. The central controller receives the NET ID from the first MET, validates the first MET for communication, validates the NET ID, allocates a frequency for the NET group, and broadcasts the message to the NET group including the second MET informing the NET group of the allocated frequency and the voice communication associated therewith. The second MET tunes to the frequency in response to the message broadcast by the central controller, and the central controller assigns the first MET as current speaker for the NET group.

Abstract: A satellite radiotelephone system includes a space-based component, a plurality of ancillary terrestrial components, and a plurality of radiotelephones. The space-based component is configured to provide wireless radiotelephone communications using satellite radiotelephone frequencies. The plurality of ancillary terrestrial components include a plurality of ancillary terrestrial component antennas configured to provide wireless radiotelephone communications using at least one of the satellite radiotelephone frequencies in a radiation pattern that increases radiation below the horizon compared to above the horizon. The plurality of radiotelephones are configured to communicate with the space-based component and with the plurality of ancillary terrestrial components. Each radiotelephone also includes a GPS signal processor and a GPS mode filter that is configured to suppress energy at (1575.42−&Dgr;) MHz, where 0<&Dgr;≦16.42 MHz. Related radiotelephones and methods are also discussed.

Abstract: A satellite radiotelephone frequency can be reused terrestrially by an ancillary terrestrial network even within the same satellite cell, using interference cancellation techniques. Moreover, the ancillary terrestrial network can use a modified range of satellite band forward link frequencies for transmission, to reduce interference with out-of-band receivers. A modified range of satellite band forward link frequencies that is used by the ancillary terrestrial network can include only a subset of the standard satellite band forward link frequencies to provide a guard band, can include power levels that monotonically decrease as a function of increasing frequency and/or can include two or more contiguous slots per frame that are left unoccupied and/or are transmitted at reduced maximum power. Time division duplex operation of the ancillary terrestrial network may also be provided over at least a portion of satellite band return frequencies.

Abstract: A mobile satellite system includes a network engineering/systems engineering (NE/SE) system. The NE/SE performs the processes of comparing expected traffic loads with capability and availability of space and ground resources in the mobile satellite system, formulating tactical plans to maximize available resources of the satellite, and producing frequency plans for different geographical regions and defining circuit pools for different groups of users.

Abstract: Data transfer efficiencies of a frequency division and/or time division multiple access (FDMA/TDMA) communication systems are improved over prior art systems by distributing signalling and messaging activities over all return channels of a channel group, by varying forward to return channel data rate ratios, and by reducing message transport delays with respect to prior art communication systems, based on message traffic over such channel group. Return channels of a defined channel group are time division controlled and are generic to operate either in a signalling mode or in a messaging mode. Data rates for the forward channel and the return channels may be selected from predefined combinations of forward and return channel data rates.

Abstract: A priority and preemption method for performing a priority and preemption process includes the steps of satisfying a resource acquisition request from a reserve pool for an external system, and when the resource acquisition request cannot be satisfied from the reserve pool, requesting additional unused frequencies, and when the additional unused frequencies are not available, requesting to preempt active calls. The method also includes the step of replenishing the power and the frequencies received from the frequency controller, the data hub and/or the independent operations controller when the frequencies are no longer needed by the priority and preemption system.

Abstract: A mobile satellite system including a satellite communication switching office and network system having a satellite antenna for receiving and transmitting a satellite message via a satellite to and from a mobile earth station including a mobile communication system, a satellite interface system, a central controller receiving and transmitting the satellite message from the mobile earth station to and from the satellite communication switching office via the satellite and the satellite interface system. The mobile communication system includes a user interface system providing a user interface through which a user has access to services supported by the mobile satellite system and an antenna system which provides an interface between the mobile communication system and the mobile satellite system via the satellite interface system.

Abstract: A communication system includes a communication switching office having a transceiver for receiving/transmitting a message from/to a data terminal using a communication system, and a management system including a central controller receiving/transmitting the message from/to the communication switching office. The central controller is responsive to the message received from the data terminal, and receives data in the message received from the data terminal. The data terminal transmits to the management system on a message channel. The message channel includes multiple messages from multiple data terminals. The management system receives the multiple messages per message channel or TDM group, and allocates message channel bandwidth for each of the multiple messages to the data terminal responsive to the data terminal call request received on the signalling channel.

Abstract: In a mobile satellite system, a system for providing satellite communication between multiple users in a virtual network arrangement includes first and second mobile earth terminals (METs) responsively connected to and registering with the mobile satellite system. The first MET selects a virtual network identifier (VN ID) representing a virtual network group including the first and second METs to establish voice communication therewith and transmits the VN ID to a central controller. The central controller receives the VN ID from the first MET, validates the first MET for communication, validates the VN ID, allocates a frequency for the virtual network group, and broadcasts the message to the virtual network group including the second MET informing the virtual network group of the allocated frequency and the voice communication associated therewith. The second MET tunes to the frequency in response to the message broadcast by the central controller.

Abstract: In a communication system in which a transmitter transmits data over a communication channel of a fixed bandwidth to a receiver, the method according to which the transmit data rate is continuously adjusted to a rate which is substantially equal to a short-term average data rate. The channel capacity and/or other characteristics of the system, is continuously adjusted, through changes in transmit power, symbol rate and modulation format, to a level at which the ratio of received signal energy per bit to noise spectral density (Eb/N0) at the receiver is close to but above its minimum acceptable level, thereby matching the channel capacity and/or other characteristics of the system to the traffic. The system has further attributes which adjust the transmit data rate responsive to conditions involving at least one of data traffic levels, power reserve emergency, thermal load and message priority.