The Boeing Company

David S Parkman

Michael De La Chapelle

Christopher John McLain

Gary V Stephenson

Paulus J Martens

David Carman

Janet L King

Joseph W Niesen

Richard A Hellman

Richard A Heilman

Christopher J Mclain

Implementations are described that use a control center to maintain a list of registered mobile platforms that are pre-authorized to make use of the satellite-based transponder to transmit and receive data content to and from the base transceiver. The control center may cause the base transceiver to transmit at least one polling message, the polling message carries information addressed to a specific aggregate group of the registered mobile platforms and includes a return channel which may be used by a mobile platform to communicate with the base transceiver. In one implementation, the control center protects the system from exceeding power spectral density (PSD) statistical limits by using the mobile platform in the group that has a greatest power spectral density signal as the PSD that the aggregate group will generate.

Aggregate batch polling method for return link communications between a platform and a base station

A satellite communications method for communicating information from a base station, via a satellite, to one or more user terminals via a single channel of a forward link.

System and method for adaptive information rate communication

A method for discovering a data routing path via satellite link to a mobile platform from a ground segment of a communications network. The mobile platform and ground segment communicate via satellite transponder. Each transponder has a dedicated ground segment equipment chain. A unique path signature is assigned to each chain. The ground segment multicasts, via the chain(s), message(s) containing the path signature corresponding to the chain(s). The platform transmits, to the ground segment, path signature(s) received by the platform via the message(s). The ground segment maintains information for controlling path discovery. Thus misrouting due to differences in transponder path identification is eliminated.

Methods and apparatus for path discovery between a mobile platform and a ground segment

A communication system and method for transmitting data to mobile platforms using multiple simultaneous channels operating at multiple data rates. Each mobile receiver has the capability to receive multiple transmit channels at multiple data rates. Mobile platforms report their position to a ground based controller which determines which communication channel can be operated without substantial loss of data. Data packets destined for each aircraft are preferably routed to the highest data rate channel that can be received by that mobile platform without substantial loss of data. This maximizes the overall system efficiency and throughput. High priority and mission critical data may be transmitted to the aircraft using low data rate channels to increase link availability.

Communications system and method employing forward satellite links using multiple simultaneous data rates

A communications system and method for transmitting data to a mobile platform is provided. The communications system comprises a forward link assignment manager in communication with a route server and a router, wherein the router selects from paths of forward link equipment chains to transmit data to the mobile platform. Generally, the forward link assignment manager assigns a cost to the path of each chain such that the more available the chain, the lower its cost, and the router always selects the lowest cost path. If a chain of forward link equipment fails, the forward link assignment manager increases its cost above that of a spare chain, which results in the router selecting the spare chain. Further systems are provided that inform the forward link assignment manager of a failed chain of forward link equipment, in addition to systems that remove a failed chain from the network topology.

Fail-over of forward link equipment

A method is provided for asymmetrically encrypting data communicated between a ground platform and multiple airborne platforms. The method includes packet encrypting ground-based data so as to preserve routing information while encrypting the remaining data. The packet-encrypted data is then transmitted to the airborne platforms. The method also includes bulk encrypting airborne-based data so as to maximize security. The bulk-encrypted data is then transmitted to the ground platform.

Encryption for asymmetric data links

A polling system and method for establishing forward and return communication links with a plurality of mobile platforms operating within a given coverage region, and further which provides preliminary return channel assignments with each polling message. Each polling message further has an associated ID code designating a particular mobile platform which is registered with a network operations center (NOC) of the system. If the mobile platform does not respond on its designated preliminary return channel within a given time period (e.g., 5 seconds) than the preliminary return channel is returned to a database of available return channels. Polling is carried out more expeditiously because groups of mobile platforms are polled simultaneously and provided with preliminary return channels which accompany the polling messages, and which direct each mobile platform to a designated return channel to use in establishing a return communications link. Polling groups are further sized according to available communication resources.

Batch round robin polling method for return link communications between a mobile platform and a base station

A communications system and method for assigning forward link transponder assignments to mobile platforms is provided. The communications system comprises at least one ground station in communication with a plurality of satellites and mobile platforms, wherein the mobile platforms receive assignments to various transponders on the satellites through the ground station based on the desired set of data or services. The communications system requires a return link from the mobile platform to the ground station so that changes in the desired data or services can be confirmed, and accordingly, a default transponder assignment table is incorporated in each mobile platform to establish the return link in the event of receiver equipment failure. The communications system further comprises a set of forward link transponder assignments loaded onto a piece of communications equipment to provide the assignments to a piece of receiver equipment in the event of receiver equipment failure.

Ground control of forward link assignments

A communications system and method for transmitting authorization messages to mobile platforms is provided. The communications system authorizes the mobile platform to continue transmitting data with a single signal rather than multiple signals. Specifically, the authorization signal comprises a unique address for a path of forward link equipment that transmits data to the mobile platform. The unique address informs the mobile platform which equipment is currently being used for data transmission, and the mobile platform then relays this information back to a ground station. The authorization signal further comprises a return link assignment that informs the mobile platform which transponder is to be used for data transmission back to the ground station. Accordingly, a single signal is used to transmit the required data to the mobile platforms.

Transmit authorization

A system and method for carrying out a hand-off of a satellite-based communications link with a mobile platform, such as an aircraft, leaving a first coverage region and entering a second coverage region. A land-based communications link connects ground stations in each of the coverage regions for communications with one another and also with a network operations center (NOC). As the aircraft enters an area of overlap between the two coverage regions, a sequence of communications is initiated between the ground stations and also between each of the ground stations and the aircraft to ensure that new forward link and return link assignments are received by the aircraft before the aircraft relinquishes its communications link with the first ground station to begin communicating with the second ground station. The hand-off in communications is accomplished in less than approximately 30 seconds of time after one of the ground stations detects that the aircraft has entered a pre-defined overlap area between the two coverage regions.

Precoordination of return link for hand-off between coverage areas being traversed by a mobile transceiver platform

A communication system and method for transmitting data to mobile platforms using multiple simultaneous channels operating at multiple data rates. Each mobile receiver has the capability to receive multiple transmit channels at multiple data rates. Aircraft report their position to a ground based controller which determines which communication channel can be operated without substantial loss of data. Data packets destined for each aircraft are preferably routed to the highest data rate channel that can be received by that aircraft without substantial loss of data. This maximizes the overall system efficiency and throughput. High priority and mission critical data may be transmitted to the aircraft using low data rate channels to increase link availability.

A polling system and method for establishing forward and return communications links with a plurality of mobile platforms operating within a given coverage region. The system and method combines preliminary return channel information and path discovery information into polling messages transmitted by a ground station. A mobile platform responding to the polling messages relayed from one of a plurality of satellite based transponders transmits a response on the designated preliminary return channel and includes the path discovery information in its response. The path discovery information informs the ground station of the precise route through various components of the forward link communications path that the polling message took in reaching the mobile platform. Combining the path discovery information and the return channel information into the forward link polling messages saves important transponder bandwidth.

Path discovery method for return link communications between a mobile platform and a base station

A system and method for assigning network addresses to mobile platforms using a satellite communications link. The network address information is transmitted from a ground station only upon request by the mobile platform, with the mobile platform transmitting a confirmation signal after receiving the network address information. Bi-directional communication is thereby provided between the ground system and specific mobile platforms. The network address information is maintained on-board the mobile platform within a plurality of components to avoid losing the information in the event of a failure of one or more on-board components operating on a network on the mobile platform.

System and method for providing network addresses to mobile platforms

A method for rapidly monitoring and detecting a mobile terminal causing RF interference with one or more satellites orbiting in the vicinity of a target satellite, from a plurality of mobile terminals accessing the target satellite. Each mobile terminal performs a transmit lobing signal sequence and a ground-based component in the form of a Network Operation Center (NOC) analyzes the signals transmitted by each mobile platform. The NOC determines a ratio of energy-per-bit to noise spectral density (Eb/No) value for the signals transmitted by each mobile platform and compares these values to a predetermined Eb/No value. If the Eb/No values for a given mobile platform deviate by more than a predetermined magnitude from the predetermined Eb/No value, then the NOC identifies that given mobile platform as causing the unintended RF interference with the adjacent satellite(s).

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Mercer Island, WA, United States of America

David S Parkman