摘要:
A system and method for selectively enabling and disabling wireless connectivity between cellular or PDA users on-board commercial aircraft having a shielded fuselage, and remotely located wireless access points, while the aircraft is at an airport or airfield. The system and method does not require access to an on-board LAN system of the aircraft. The system includes one or more antennae disposed in the cabin area of the aircraft that are coupled via an RF switch with an exterior antenna mounted on an exterior of the fuselage. The RF switch is controlled by a switch control subsystem, and enables or disables communication between the interior antennae and the exterior antenna. The exterior antenna is connected to the switch via a conductor that extends through the shielding of the aircraft. When the RF switch is in the closed position, cellular or PDA users can connect through the interior antennae and the exterior antenna directly to remotely located wireless access points.
摘要:
A method and apparatus for creating an antenna system. A configuration for a plurality of antenna cells is selected for an antenna in the antenna system. Each antenna cell in the plurality of antenna cells comprises a plurality of antenna elements having a symmetric arrangement. A portion of antenna elements in the plurality of antenna elements for each antenna cell in the plurality of antenna cells on a substrate is selected to transmit electromagnetic waves.
摘要:
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.
摘要:
A communications system and method for providing a cellular communications link between a user traveling on a mobile platform (or at a remote location) and a terrestrial based segment. The system and method uses a radio access segment located on board the mobile platform (or at the remote location) to interface with the user's personal communications device. The bearer terminal facilitates the transmission of information to and from the radio access segment, via an off-platform system, to the terrestrial segment. The terrestrial segment manages the communications link between one or more cellular service providers who are accessing the terrestrial segment and the mobile platform (or a remote site). The system does not limit access to the terrestrial segment to only one cellular service provider but instead allows virtually any number of cellular service providers to access the terrestrial segment and to participate in providing a cellular link to the mobile platform (or a remote site).
摘要:
A system and method for preventing use of cellular/PDA devices on-board a mobile platform, such as an aircraft. The system involves using the shielding of the fuselage of the aircraft to provide a first degree of signal-to-noise ratio attenuation of signals from terrestrial wireless access points entering into the interior cabin area of the aircraft. A noise floor lifter subsystem raises the noise floor level within the aircraft to provide a second degree of attenuation of the signal-to-noise ratio of the signal entering the aircraft. By using the shielding of the fuselage, communication of the cellular/PDA devices can be prevented with a lesser degree of noise floor lifting within the aircraft, thus reducing the chance of interference with terrestrial wireless access points and/or interference with important navigation or avionics subsystems within the aircraft.
摘要:
A system and method for implementing soft handoffs in a cellular communications system on a mobile platform. The system employs an antenna controller in communication with a beam forming network that generates two independently aimable lobes from a single beam. The single beam is radiated by a phased array antenna on the mobile platform. In an Air-to-Ground implementation involving an aircraft, a base transceiver station (BTS) look-up position table is utilized to provide the locations of a plurality of BTS sites within a given region that the aircraft is traversing. The antenna controller controls the beam forming network to generate dual lobes from the single beam that facilitate making a soft handoff from one BTS site to another. In a ground-based application, one lobe of the beam is used to maintain a communications link with one BTS site while a second lobe of the beam is continuously scanned about a predetermined arc to receive RF signals from other BTS sites and to determine when a new BTS site has become available that will provide a higher quality link than the link presently made with the one BTS site. A soft handoff is then implemented from the one BTS site to the new BTS site.
摘要:
A method of coordinating communications between ground stations and fixed beam satellites is provided, wherein each beam of a satellite antenna is assigned a color to create a color pattern that matches a frequency reuse pattern for the antenna, thereby using the same frequencies in a different beam with the same color. In operation, a ground station requests a virtual channel number from a resource manager, which sends a virtual channel number that is not used by another ground station within a beam diameter of the requesting ground station. The ground station then determines the position of the satellite, the beam and beam color, and further computes the frequency, polarization, and time slot, among other information, to communicate with the satellite. A method is also provided for managing virtual channels that comprises a network manager that groups ground stations and limits the number of virtual channels per group.
摘要:
A communications system and method for providing a cellular communications link between a user traveling on a mobile platform (or at a remote location) and a terrestrial based segment. The system and method uses a radio access segment located on board the mobile platform (or at the remote location) to interface with the user's personal communications device. The bearer terminal facilitates the transmission of information to and from the radio access segment, via an off-platform system, to the terrestrial segment. The terrestrial segment manages the communications link between one or more cellular service providers who are accessing the terrestrial segment and the mobile platform (or a remote site). The system does not limit access to the terrestrial segment to only one cellular service provider but instead allows virtually any number of cellular service providers to access the terrestrial segment and to participate in providing a cellular link to the mobile platform (or a remote site).
摘要:
One or more decoys (22) are towed by an aircraft (18) to confuse hostile radar. The tow lines (20) to the decoys (22) include fiber optic components which optically transmit to the decoys (22) both radio frequency signals for retransmission to hostile radar (24), and direct current power. The fiber optic components absorb strain forces imposed by towing the decoys (22). Multiple decoys (22) are deployed at varying distances from the aircraft (18) to increase the overall range of frequencies covered by the system, simulate a plurality of false targets, or accomplish angle gate deception. The deception may be accomplished by transmitting signals from the decoys in sequence and can be enhanced by dynamically varying the power levels of the decoy transmitting antennas. The fiber optic components may be separate optical fibers deployed separately or joined together for simultaneous deployment. The preferred configuration is a single optical fiber with coaxial inner and outer cores. The decoy preferably has a transmitting antenna in the form of a simulated biconical dipole. In one embodiment, both halves of the dipole are simulated by a set of fins. In another embodiment, the forward half is simulated by a truncated cone.
摘要:
The optical power emitted from a light energy producing diode is stabilized over temperature using a simple bias circuit consisting of a voltage source with a series resistance or a current source with a shunt resistance. The bias circuit resistance is equal to the slope of the bias line formed by the constant optical power bias points of the diode plotted on a voltage versus current graph. The voltage source or current source value in the bias circuit is equal to the zero current or zero voltage intercept value, respectively.