摘要:
A method and apparatus for providing half-duplex communications for a Very Small Aperture Terminal (VSAT) operating on a continuous received stream is disclosed. The method includes: decoding the continuous received stream to establish synchronization with the continuous received stream; locating, in the continuous received stream, a time plan including a receiving timeslot and a transmitting timeslot; demodulating the continuous received stream by adapting to a timing and frequency variation of the continuous received stream in the receiving timeslot, freewheeling the adapting of the continuous received stream during the transmitting timeslot, and resuming the adapting of the continuous received stream when the transmitting timeslot ends; stopping a receiving of the continuous received stream during the transmitting timeslot; and transmitting from the VSAT during the transmitting timeslot. The freewheeling includes saving a signal acquisition parameter at the start of the transmitting timeslot and restoring the saved signal acquisition parameter at the end of the transmitting timeslot.
摘要:
A communication system is described. The system includes: at least one gateway able to provide broadband connectivity, a set of ground terminals, and a set of aerial platforms, where at least one aerial platform is able to communicate with at least one gateway using radio frequencies, each aerial platform is able to communicate with ground terminals using radio frequencies, and each aerial platform is able to communicate with each other aerial platform using radio frequencies. An automated method for determining a beam direction for communication among UAVs includes: dividing a space around the UAV into multiple sub-regions, and, iteratively: selecting a sub-region from among the multiple sub-regions; pointing a signal toward the sub-region; and determining whether a signal is received from another UAV, until all sub-regions from among the multiple sub-regions have been selected.
摘要:
Systems and methods are described that use the downlink and uplink frequency bands of the fixed satellite service (FSS) and direct broadcast service (DBS) systems to provide broadband access to aerial platforms including aircraft, drones, and unmanned aerial vehicles (UAVs) such as balloons. The secondary service aerial platform transmitters are configured to avoid interference into the primary satellite service receivers. The aerial platform may be able to detect and connect to the cell site with the strongest signal. The aerial platform may be able to handoff from one cell site to another. Systems and methods are described that provide broadband access to ground terminal via aerial platforms such as drones and UAVs such as balloons.
摘要:
A two-way satellite communication system is provided that is particularly suited for use in remote and underdeveloped areas of the world. The system utilizes an icon-based graphical user interface that can be used by illiterate users, as well as portable and renewable power sources for use in remote areas without electrical power. The system can be used to transmit educational/informative materials to populations residing in remote and underdeveloped areas, as well as to provide the means for people in such areas to transmit emergency messages to appropriate organizations/groups. The system preferably utilizes a combination satellite antenna and solar power generator that functions as an omni-directional satellite antenna and an omni-directional solar collector.
摘要:
A satellite communication system between a source and a destination over multiple satellite communications paths including first identifying the link performance established in multiple spectrums, performing a link comparison among the multiple spectrums (for example C-, Ku-, or Ka-Band] in order to determine a spectrum link that provides the highest throughput within an acceptable reliability criteria, and switching among the multiple spectrum links to provide that determined spectrum link between the source and the destination.
摘要:
L'invention concerne un procédé et une architecture système permettant d'établir de manière dynamique un ou plusieurs tunnels chiffrés sur des réseaux de communication à bande contrainte. Elle permet notamment de chiffrer un ou plusieurs flux de données tout en garantissant la qualité de services sur les systèmes à bande contrainte, en particulier pour les flux chiffrés de type voix sur IP (protocole internet) ou de type données ou en anglo-saxon Data. Ces tunnels sont ainsi adaptés au plus juste aux flux de données utiles tout en permettant de contrôler et d'affecter les valeurs nécessaires à la qualité de service ou QoS sur ces réseaux.
摘要:
L'invention concerne un procédé pour l'allocation temporelle d'une ressource de communication satellite et un système de communication associé. Le procédé comporte : (i) l'émission (202), par le terminal, d'une requête indiquant la date d'entrée d'un message dans le système et son exigence temporelle et (ii) l'allocation (204) de la ressource de communication au message, en réalisant un traitement des requêtes par un calcul d'un ordonnancement des messages en prenant en compte la date d'entrée du message dans le système et son exigence temporelle.
摘要:
An orthogonal frequency division multiple access (OFDMA) scheme is used in a satellite environment to reduce narrowband interference, impulse noise, and signal degradation. The symbol timing of each of the satellite network's multiple terminals may be synchronized, and their frequency separation chosen to obtain near orthogonality condition at the reception, between the wanted demodulated channel, and the transmissions on neighbor channels. The establishment of symbol synchronization between various remote terminals may utilize a central clock which may be recovered from a reference downstream channel from one or more satellites; or where two or more satellites are utilized, the satellites may coordinate to provide a single reference clock to the remote user terminals. The terminals may be provided with additional satellite location information relating to slight movement of the satellites around a nominal location so that the timing of transmissions may be corrected based on a tracking algorithm for detecting slight movement of the satellites. The tracking algorithm may be accomplished with individual timing correction to each of the remote terminal's transmissions. A central hub may enforce global timing by utilizing an individual timing correction loop over the network, and enforce global timing synchronization by sending frequent individual timing correction requests and receiving acknowledgements.
摘要:
A system for directing an antenna (111) for transmission over a two-way satellite network is disclosed. A transceiver (109) is coupled to the antenna (111); the transceiver (109) transmits and receives signals over the two-way satellite network. A user terminal (101) is coupled to the transceiver (109) and executes an antenna pointing program. The program instructs a user to initially point the antenna (111) to a beacon satellite (107) using predefined pointing values based upon the location of the antenna (111). The program receives new antenna pointing parameters that are downloaded from a hub (113) over a temporary channel that is established via the beacon satellite (107). The program displays the new antenna pointing parameters and instructs the user to selectively re-point the antenna (111) based upon the downloaded new antenna pointing parameters.
摘要:
A method and apparatus for zero interference multi-gigabit inter-satellite communication between system satellites (300) and client satellites (301) using millimeter wave beams at transmit and receive frequencies that are aligned to the peak atmospheric molecular absorption frequencies in the electromagnetic spectrum (Fig. 1). The narrow low power beams are accurately steered within a restricted set of directions (Fig. 5) that prevent interference to other space borne radio receivers whether in geostationary or low earth orbits and cannot interfere with terrestrial receivers due to atmospheric absorption. The apparatus comprises an integrated electronically steered 2-D phased array (401), transceiver and baseband integrated circuits (402, 403) with a beam controller (404) coupled to the spacecraft attitude determination and control subsystem (407), central processing unit (406) and solid state storage device (405).