Stanford Telecommunications, Inc.

Itt Manufacturing Enterprises, Inc.

Other

Leonard Schuchman

Ronald C Bruno

Lloyd Engelbrecht

Aaron Weinberg

Kenneth D Cunningham

Charles Moses

Edward J Zakrzewski

Steve Greenberg

John Kefaliotis

Joseph Smallcomb

Robert Rennard

Hatch Graham, Iii

Robert McCarthy

John E Miller

An air traffic control automatic dependent, WAAS/GPS based, surveillance system (ADS), for operation in the TRACON airspace. The system provides encryption protection against unauthorized reading of ADS messages and unauthorized position tracking of aircraft using multilateration techniques. Each aircraft has its own encryption and long PN codes per TRACON and transmit power is controlled to protect against unauthorized ranging on the ADS-S aircraft transmission. The encryption and PN codes can be changed dynamically. Several options which account for available bandwidth, burst data rates, frequency spectrum allocations, relative cost to implement, complexity of operation, degree of protection against unauthorized users, system capacity, bits per aircraft reply message and mutual interference avoidance techniques between ADS-S, ADS-B Enroute and Mode S/ATCRBS TRACON are disclosed. ADS messages are only transmitted as replies to ATC ground terminal interrogations (no squittering). Derivative surveillance backup systems provide an anti-spoofing capability.

Automatic dependent surveillance system secure ADS-S

Positioning system for locating a mobile body comprising a plurality of earth based spread spectrum (SS) broadcasting stations arranged geographically in a cellular pattern. Each SS broadcasting station include a modulator providing a channel signal structure which is substantially orthogonal with respect to adjacent stations in the cellular pattern, each channel signal including navigation beacon data including a unique beacon identification, station latitude and longitude, time_slot and phase characterizations and selected parameters of adjacent stations. In one embodiment, each modulator provides a chirped SS signal in which the navigation beacon is a frequency tone that is repeatedly swept over a selected frequency band for each station. In a further embodiment, each modulator provides a GPS like direct sequence SS signal in which the navigation beacon is a PN coded broadcast. A receiver on the mobile body receives the SS signals from at least three of the SS broadcasting stations and determines the location thereof. A fourth SS broadcasting station provides altitude CPS satellite signals can be used for timing control.

Cellular positioning system (CPS)

A cellular telephone system having three or more cell sites with each cell site having a source of cellular communication signals and an RF transmitter and antenna for broadcasting the cellular communication signals. A direct sequence spread spectrum waveform carrying navigation signals is embedded in the cellular communication signals, including controlling the signal strength of the navigation signals so that the combined energy of the navigation signals from all cell sites at any location is at least a predetermined energy level below the energy level of the cellular communication signals. Each cell site includes timing for timing the operation of a GPS receiver. An RF signpost system comprising a plurality of low powered RF broadcast stations, one each at a plurality of scattered geographic locations, each low powered RF broadcast station broadcasting a direct sequence spread spectrum digital RF waveform and means to modulate the digital RF waveform with location information identifying the geographic locations, respectively.

Position enhanced communication system including system for embedding CDMA navigation beacons under the communications signals of a wireless communication system

A mobile unit includes a network receiver, such as a GSM telephone, for communication with a wireless network, and a navigation receiver, such as a global positioning system (GPS) receiver for receiving navigation signals. The navigation receiver includes a vector delay lock loop (VDLL) that receives information concerning the navigation sources, such as satellite data messages, transmitted over a common broadcast channel of the wireless network, and receives navigation signals from the navigation receiver. The VDLL uses the navigation signals received from navigation sources that are not obscured and uses satellite data messages broadcast over the wireless network to track a navigation signal that is received only intermittently due, for example, to the navigation source being obscured from view of the mobile unit.

Hybrid system for position determination by a mobile communications terminal

A position enhanced cellular telephone system wherein a cellular telephone device incorporates an RF position finder facility, a data modem and controller and a car alarm device, having a system for flexibly merging the functionality of the telephone device, position finder facility, data modem, controller, and car alarm, reduce overall components and lower the cost. A microprocessor, with a memory, is provided with a plurality of data input and output terminals. Car alarm and position signals from said RF position finder facility to an input terminal on the microprocessor. A signal conversion circuit converts RF to baseband and vice versa, and electronic switch device controlled by the microprocessor for coupling RF signals to and from the cellular telephone device to the signal conversion circuit. A digital signal processor (DSP) coupled to said microprocessor and controlled thereby, said DSP being adapted to a microphone and a speaker connected to the DSP, and the DSP is coupled to the signal conversion circuit.

Integrated vehicle applique unit for the position enhanced cellular system

An accessory device for portable telephones which provides simultaneous functionality of a hands-free accessory device and a data-in-voice modem enabling a portable telephone to be used in a vehicle such that the driver can be engaged in a hands-free conversation at the same time as data (such as GPS position information) is being sent over the same cellular voice channel.

System for providing a simultaneous data and voice channel within a single channel of a portable cellular telephone to provide position-enhanced cellular services (PECS)

A monitoring and location system comprising a service center from which movement to and from a prescribed local area and a prescribed wide area is to be monitored. Each member of a class being monitored is provided with a personal RF transponder unit (RFTU). Each RF transponder unit has a digital electronic identification number (DEIN) embedded therein for transmission by RF upon request. RF transceiver interrogation units define specific egress/ingress zones for the prescribed areas. Each interrogation unit being connected to the service center to god signal (1) when an RFTU has egressed or ingressed a prescribed area and (2) the DEIN embedded therein. The RF transceiver interrogation units can determine distance and bearing to a given RFTU and DEIN. When there are a plurality of cell sites encompassing the prescribed areas, an RF transceiver interrogation unit at each of the cell sites, respectively, are connected to the service center. Each RFTU has an emergency signalling component which, when activated, causes a range and bearing measurement to that RFTU to be made and sent to the service center for action.

Personal location system

A method of avoiding near-far interference problems in a cellular ray of navigation signal beacons having selected CDMA or GPS-like navigation signals. The navigation signals from adjacent navigation signal beacons are pulsed so that adjacent navigation signal beacons do not broadcast navigation signals simultaneously and the multiple frequencies are coordinated in a time divisional multiplex manner. In another aspect, the near-far interference problem is avoided by using multiple frequencies in time division multiplexing and coordinating the use of the multiple frequencies and the time division multiplexing to assure avoidance of the near-far interference problem.

Method of avoiding near-far interference problems in an array of

A cellular telephone communication system has at least one base station and a plurality of remote mobile stations in which both base and mobile stations have RF transceivers which communicate with each other using periodically repeated pulse sequence epochs whose time patterns are known at both transmitting and receiving station. Each mobile station transceiver, during normal operation, establishes and maintains synchronization between the start of a received pulse epoch at the mobile station and a subsequent beginning of a responsive transmitted pulse epoch. An agile antenna system is located at the base station and includes at least one scanning antenna spaced a selected distance from a central reference point. The scanning antenna is effectively rotated relative to the central reference point and adapted to receive RF transmissions from a selected mobile station, and a direction or bearing detection processor is connected to antenna systems for detecting from received RF transmissions from the selected mobile station the bearing to the selected mobile station from the base station. The bearing sensing processor is one selected from amplitude sensing, phase sensing or frequency sensing or a combination of these sensing principles. A range measuring processor circuit also at the base station measures the time interval from the start of the base station's transmitted pulse epoch to the start of a pulse epoch subsequently received from the selected mobile station and derives range to the selected mobile station therefrom.

Phase agile antenna for use in position determination

Base station and system modifications to a digital cellular telephone system that measures location of a mobile station from its normal transmissions, and can forward the measured position to that station or some other authorized caller or service on the communication network. Range measurement is enabled without modification of mobile station equipment because of the synchronization between received pulse epochs and transmitted ones that are required for normal operation in digital telephony. Range measurement is made at a base station currently in contact with the mobile station by measuring the time interval from the start of its own transmitted pulse epoch to the start of a pulse epoch subsequently received from the mobile station, then dividing that time interval by twice the velocity of radio waves. Direction from the base station is determined, in a preferred embodiment, by use of a planar phase steered antenna array synchronized to pulse sequences from the mobile station.

Positioning system for CDMA/PCS communications system

Positioning system for locating a mobile body comprising a plurality of earth based spread spectrum (SS) broadcasting stations arranged geographically in a cellular pattern. Each SS broadcasting station include a modulator providing a channel signal structure which is substantially orthogonal with respect to adjacent stations in the cellular pattern, each channel signal including navigation beacon data including a unique beacon identification, station latitude and longitude, time.sub.-- slot and phase characterizations and selected parameters of adjacent stations. In one embodiment, each modulator provides a chirped SS signal in which the navigation beacon is a frequency tone that is repeatedly swept over a selected frequency band for each station. In a further embodiment, each modulator provides a GPS like direct sequence SS signal in which the navigation beacon is a PN coded broadcast. A receiver on the mobile body receives the SS signals from at least three of the SS broadcasting stations and determines the location thereof. A fourth SS broadcasting station provides altitude. CPS satellite signals can be used for timing control.

A multiple access RF communication system in which a plurality of mobile user transceivers communicate with a central hub transceiver through an earth orbiting satellite, and wherein groups of mobile user transceivers in close proximity with each other share a common multi-access inbound (to hub) frequency F.sub.l and a common outbound channel (from hub) frequency F.sub.o. Each said mobile user transceiver includes a continuously listening receiver for the outbound channel and a half-duplex transceiver on the inbound channel, determining the busy or idle status of the common inbound frequency F.sub.1, and a device to indicate the status of the carrier outbound channel, which controls the ability to transmit on the inbound channel.

Multi-access CS-P/CD-E system and protocols on satellite channels

A digital broadcast system, comprising a master radio broadcast station located at a main predetermined location for formatting and broadcasting a plurality of channels of digitized program data in a spread spectrum, time and frequency hopping waveform to remote mobile and stationary receivers. A plurality of relatively low power range extension radio broadcast stations are provided, each said range extension station being located in selected areas and, each range extension station being adapted to receive and store one or more channels of program information from the master station. A separate program distribution system coupling the received and store of each range extension radio broadcast station with the master radio broadcast station, said separate distribution system, including, for each range extension station at least one path selected form satellite, microwave, fiber-optic, coaxial cable and telephone paths, for coupling one or more channels of program information to each range extension station. The channels of digital data re-broadcast from each of the range extension radio broadcast stations is synchronized with broadcasts from the master radio broadcast station such that a mobile receiver traveling between edges of reception of two or more low power range extension radio broadcast stations does not evidence interference therebetween.

Digital broadcast system

Air traffic surveillance and communication system

A GPS system has a plurality of satellites transmitting time and location data over radio frequency signals which enable a mobile GPS receiver on the ground to determine its position, includes a source of satellite data message block containing the ephemeris and time modes of the GPS satellites which is independent of the satellites, and an independent cellular telephone channel having a voice channel, a data-in-voice modem including a notch filtering circuit in the voice channel (transmits and receive) and circuits for inserting and retrieving data in and from the notch for accessing said satellite data message block and controller means connecting said satellite message data block to said mobile GPS receiver.

Growing community of inventors

Potomac, MD, United States of America

Leonard Schuchman