Orion Industries, Ltd.

General Electric Company

Allen Telecom Group, Inc.

Samuel A Leslie

Michael W Evans

Robert T Gordon

William A Bowen

Arne B Bendixen

Jon M Newgard

Walter C Pitts

Mark M Sihlanick

John J Hurley

Donald J Umbdenstock

Robert C Schwartz

A system which improves coverage in overlapping coverage areas between two type-A or type-B cellular radio telephone systems is able to direct a subscriber unit in the overlapping coverage area to the home or primary system, thereby minimizing the subscriber unit's roaming-type expenses. The system includes a control channel receiver, a control unit, and a control channel transmitter/receiver pair, in combination with a transmit/receive antenna. The system transmits a control channel, which is associated with the home system, into the overlapping region. The control channel is intended to be the strongest channel in that region. Any subscriber units in the region associated with the home system which respond to that control channel will be directed to other control channels associated with the home system. Those subscriber units will receive service from the home system, as opposed to the foreign system which may provide other strong control channels in the overlapping coverage area.

Apparatus and method for preserving coverage in an overlapping coverage

A cell extender for use in digital cellular telephone systems comprises a control module, and scanning module, and several traffic modules. The control module bidirectionally repeats the donor cell site control channels. Voice modules therein bidirectionally repeat selected donor traffic channels for mobiles. The voice module amplifies and translates the Reverse Digital Traffic Channel RDTC (transmitted by the mobile). The voice module reframes the Forward Digital Traffic Channel, and advances its timing such that RDTC signals transmitted by the mobile and repeated by the cell extender arrive at the donor with the correct timing alignment. The timing advance compensates for RF path propagation delay between the donor and the cell extender, and for any additional delay through the cell extender. If the voice module determines that the mobile is leaving the cell extender coverage area, it sends a hand-off message returning the mobile to the assigned donor traffic channel.

Cell extender with timing alignment for use in time division

An apparatus and method which can provide a private cellular system within an area already served by a public cellular system include a receiver for receiving RF control signals from the public system. The public system control signals are converted to saturation level control signals from the private system. Subscriber units to be serviced by the public system are directed thereto. Those associated with the private system can be serviced directly.

Apparatus and a method of allowing private cellular operation within an

A system and method for handing back a movable transceiver to a different cell site from the original cell site includes circuitry for sensing signals from the movable transceiver which are transmitted on a modified frequency as well as circuitry for translating those signals back to their originally assigned frequencies without changing the detected field strength of the signal, in combination with circuitry for forwarding the translated signals to the different cell site for hand-off evaluation. The method includes sensing the received signals, translating the received signals to an originally assigned frequency based on either a fixed offset or other provided information concerning the translation along with a step of continually updating those frequencies which are to be retranslated.

Multi-donor booster operation and system

A diversity receiving apparatus includes first and second antennas and circuitry for selecting one antenna or the other. Control circuitry analyzes signal strength received from the selected antenna and determines when the antennas should be switched. The antennas are switched when the received signal strength falls below a running average thereof; the received signal strength falls below a threshold value; or a predetermined time has elapsed since the antennas have been switched. The antennas are switched when the received signal strength falls below a running average thereof; the received signal strength falls below a threshold value; or a predetermined time has elapsed since the antennas have been switched.

System and method for switching between antennas in a radio frequency

A system and a method for extending coverage of a cell site in a cellular radio telephone system include a plurality of repeaters or boosters which are spaced through the region where increased coverage is desired. A first booster is in radio communication with the transceiver for the cell site. The remaining boosters are linked together, by radio transmissions, in a series configuration with only one of those linked to the first booster. A movable transceiver operating in the extended area of coverage is in radio communication with the closest booster unit and, via the serial chain of boosters in communication with the controlling cell site. As the movable unit moves along the extended area of coverage from one booster area to another, it is automatically picked up by the approaching booster and dropped by the receding booster while continuing to be in communication ultimately with the cell site via the series coupled booster chain.

System and method for extending cell site coverage

A cellular communication system booster has plural narrowband and wideband channels each having down mixers, local oscillators, IF filters, and amplifiers for amplifying communication signals. On a narrowband channel preferably not in use, and preferably in a time-multiplexed manner, a reference signal of known signal strength is substituted at the output amplifier in lieu of a normal communications signal. When this amplified reference signal is broadcast at the output antenna a portion of the signal is feed back to the input antenna due to imperfect isolation between the antennas. This feedback signal is measured by a Radio Signal Strength Indicator (RSSI) circuit at the point of its receipt into the IF filter of the narrowband channel. The measured signal strength serves as a measurement of signal isolation/feedback between the antennas. A microprocessor receiving the measurement and knowledgeable of the reference signal strength controls the gain of the channel amplifier so as to maintain the feedback signal 10 dB below the reference signal, thereby preventing RF signal feedback oscillation. In different embodiments the reference signal may be derived from an injection oscillator or, alternatively, from an actual communication signal upon another communications channel. Isolation/feedback measurements are typically stepped across multiple channels spanning the entire communications frequency band, thereby providing measurement and appropriate control at all frequencies and operational conditions.

Measuring and controlling signal feedback between the transmit and

An apparatus for detecting excessive output power from a cellular radio telephone system booster includes input circuitry for receiving incoming radio frequency signals from a mobile source. Amplifiers are provided for amplifying the radio frequency signals either directly or by means of intermediate frequency channels. The output power amplifiers have variable gain. Circuitry detects when the transmitted radio frequency signals exceed a predetermine threshold and reduce the amplifier gain accordingly.

Repeater with feedback oscillation control

A method for optimizing antenna orientation in a cellular radio telephone system with respect to a predetermined criterion of signal level includes the steps of orienting the antenna in a selected direction, sensing a selected received signal in a predetermined frequency range, mixing the selected received signal with the control signal so as to generate a corresponding intermediate frequency signal in an intermediate frequency transmission path, measuring a selected parameter of the intermediate frequency signal and then altering the orientation of the antenna while subsequently repeating the required steps. The preferred antenna orientation can be determined by examining the results of the various measurements and selecting an antenna orientation which maximizes the signal level of the desired received signal.

Optimization system and method

A diversity receiving apparatus includes first and second antennas and circuitry for selecting one antenna or the other. Control circuitry analyzes signal strength received from the selected antenna and determines when the antennas should be switched.

Booster diversity receiving system usable with cellular booster

An apparatus and method for selecting a number of cellular radio channels to be boosted in a given geographical area provides either F1-F1 or F1-F2 operation. The signals can be boosted at the same frequency with input to output isolation being achieved by the use of directive transmit and receive antennas physically positioned to achieve sufficient isolation. Each signal is individually filtered, amplified, and recombined for transmission. Any number of signals may be accommodated depending upon the number of retransmission channels available. Apparatus is also provided to retransmit a signal at a different frequency from that at which it is received. A tag, typically an audio tone or diminished signal amplitude gap, may be selectively applied to boosted retransmitted signals in order that they may be recognized as such.

Booster with detectable boost operation

An apparatus and method for selecting a number of cellular radio channels to be boosted in a given geographical area provides either F1-F1 or F1-F2 operation. The signals are be boosted at the same frequency with input to output isolation being achieved by the use of directive transmit and receive antennas physically positioned to achieve sufficient isolation. Each signal is individually filtered, amplified, and recombined for transmission. Any number of signals may be accommodated depending upon the number of retransmission channels available. Apparatus is also provided to retransmit a signal at a different frequency from that at which it is received.

Booster

A system for coupling a plurality of telephones or local units to a remote land line telephone system includes a line interface associated with each of the telephones or local units. Each of the line interfaces is in turn coupled to an audio switch matrix. Outputs and inputs to and from the audio switch matrix are coupled to a 4 to 2 wire hybrid, a tone interface hybrid and a computer based control unit. The control unit includes a programmed microcomputer with interface circuits enabling it to communicate with and to control the line interfaces and the audio switch matrix. The computer also includes interface circuits enabling it to communicate with and control a radio transceiver. The radio transceiver is in radio frequency communication with a corresponding radio transceiver remotely located and coupled to the remote land line telephone system. Communications with the remote land line telephone system can be initiated by any of the local units. Additionally, communications from the remote land line telephone system can be received at each of the local units, only if at least one unique identifier is received by the transceiver of the local unit.

Cellular remote station with multiple coupled units

Communications transceiver set

A vehicular radio transceiver is normally powered by a vehicular ignition switch and a transceiver on-off switch both being closed. A latch circuit senses the presence of communication over the transceiver, and produces a latch signal that powers the transceiver despite opening of either of the switches.

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Forest, VA, United States of America

Samuel A Leslie