The present invention pertains generally to satellite communications systems. More particularly, the present invention pertains to satellite communications systems wherein a Local Area Network (LAN) is mounted on a moving vehicle. The present invention is particularly, but not exclusively, useful in a satellite communications system wherein the combination of components for communication and antenna control can be customized for operational compatibility, to thereby establish and maintain a data path between the moving vehicle and the satellite.
Satellite communications systems rely on the ability of a LAN to establish and maintain a data path between the station and the satellite. Not surprisingly, this is no easy task. Moreover, the ability to operationally maintain the data path becomes increasingly complex when the LAN is mounted on a moving vehicle. Accordingly, the operational control of an antenna assembly that is suitable for use with the moving vehicle is a very important design consideration.
As a practical matter, there are many different types of moving vehicles (i.e. airborne, terrestrial and maritime), and they will each have their own respectively unique and different operational requirements. A consequence of these differences is that different types of antenna assemblies are typically required. Further, as implied above, each antenna assembly will necessarily have its own control requirements. On top of this, operational flexibility may require the ability to change the configuration of a particular LAN and/or its antenna assembly. More specifically, there are situations wherein it may be desirable to replace one antenna assembly with another type antenna assembly. In such a case, as well as in other cases wherein moving vehicles have unique but changed requirements, the ability to substitute one antenna assembly for another may be desirable. In the event, system component compatibility and interoperability must be established.
In light of the above, it is an object of the present invention to provide a customized satellite communications system with the capability of individually or collectively substituting operationally essential components, such as an antenna assembly, without compromising the system's operational compatibility. Still another object of the present invention is to provide a satellite communications system that can establish and maintain a data path between a satellite and a moving vehicle. Yet another object of the present invention is to provide a satellite communications system with a flexible methodology for changing operationally compatible components that is easy to perform in a cost effective manner.
In accordance with the present invention, a system is provided for use in connecting a LAN into a satellite communications network. Specifically, the system is provided to establish a central management interface between the electronic components that interchange operational data. In particular, this interchange of data is accomplished by the system to control the components that establish and maintain a data path between the LAN and a satellite. As envisioned for the present invention the system will be mounted on a moving vehicle that may either be airborne, terrestrial or maritime.
Components for the system of the present invention include a services platform, an antenna assembly, an Antenna Control Unit (ACU), an Inertial Reference Unit (IRU) and a modem. For communication purposes, the antenna assembly is connected to the modem, and the modem is connected with the services platform. In turn, the services platform is connected to the LAN. Thus, the LAN is connected in communication with the antenna assembly. On the other hand, for control purposes, the antenna assembly is connected with the ACU, and the ACU is connected via the services platform with the IRU. Thus, the antenna assembly is operationally controlled by the ACU to establish and maintain a communication data path between the LAN and a satellite.
For operational control of the antenna assembly, the IRU generates parametric values that are transferred by the services platform for input to the ACU. More specifically, these parametric values are indicative of both a spatial attitude of the moving vehicle (e.g. pitch, roll and yaw), and a location of the moving vehicle (e.g. position, altitude and velocity). Typically, the location information can be provided by a GPS capability. In the event of a GPS failure, however, the system of the present invention can revert to inertial sensing techniques for its location information.
In operation, under control from the services platform, the ACU converts input from the IRU into antenna orientation parameters. More specifically, based on inputs from the IRU, the antenna assembly is dynamically oriented by the ACU in response to movements of the vehicle. Thus, movements of the antenna assembly are controlled with appropriate elevation, azimuth and polarization inputs to establish a data path between the antenna and the satellite. At the same time, also under control from the services platform, system signals will be converted between Ku-band (used on the data path between the moving vehicle and the satellite) and L-band (between the LAN and the modem and between the modem and the antenna). Further, the services platform and modem encode/decode and assemble/disassemble data. The services platform will also direct data transmissions in the LAN.
The novel features of this invention, as well as the invention itself, both as to its structure and its operation, will be best understood from the accompanying drawings, taken in conjunction with the accompanying description, in which similar reference characters refer to similar parts, and in which:
Referring initially to
For purposes of this disclosure, consider the moving vehicle to be the airborne vehicle 16, and that it is in communication with the central facility 28. As shown in
With reference to
For the communication functions of the present invention, consider the data path 32 that extends between the satellite 12 and the LAN 14. Keep in mind, this will be a two-way communications data path 32 for both transmit and receive by the LAN 14. Between the satellite 12 and the system 30, the data that is carried on the data path 32 will be carried on Ku-band. Data that is received by the antenna assembly 40 will be passed to a system 30 where it is converted from Ku-band to L-band. In concert with the services platform 38, the modem 44 will then also be used to encode/decode and assemble/disassemble the packets of data that are being transmitted on the data path 32. Further, at the services platform 38, the communications data on data path 32 is sorted and routed through the switch 42 for further transmission to appropriate stations in the LAN 14.
For the orientation function of aiming the antenna assembly 40 toward the satellite 12, the system 30 of the present invention incorporates an Antenna Control Unit (ACU) 46 and an Inertial Reference Unit (IRU) 48. As shown, the ACU 46 is connected to the antenna assembly 40, and it is controlled by the services platform 38, for the purpose of moving the antenna assembly 40 to maintain the data path 32 between the system 30 and the satellite 12. As also shown, the IRU 48 is controlled by the services platform 38 to generate inputs of parametric values to the ACU 46 which are indicative of a spatial attitude of the vehicle 16, and its location. In particular, the parametric values for measuring the spatial attitude of the moving airborne vehicle 16 include measurements of pitch, roll and yaw. On the other hand, parametric values for identifying the location of the moving vehicle 16 include position, altitude and velocity. Preferably, the parametric values for the location of the moving vehicle 16 are obtained by selectively using GPS or inertial sensing techniques. Based on these inputs the antenna assembly 40 is dynamically oriented with elevation, azimuth and polarization inputs from the ACU 46.
While the particular Airborne Satellite Communications System as herein shown and disclosed in detail is fully capable of obtaining the objects and providing the advantages herein before stated, it is to be understood that it is merely illustrative of the presently preferred embodiments of the invention and that no limitations are intended to the details of construction or design herein shown other than as described in the appended claims.
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Number | Date | Country | |
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20130307725 A1 | Nov 2013 | US |