Cellular telephone zone system
First Claim
1. A method for marking a predefined zone independent of a cellular telephone system and for determining if a mobile unit is located within the predefined zone, said cellular telephone system including a cell site transceiver that transmits and receives signals to and from a mobile unit on one or more control channels in a cell site, the method comprising the steps of:
- transmitting a zone identification signal on a marker channel that identifies said predefined zone said zone identification signal being transmitted from a first marker transmitter having a radio frequency coverage area that includes at least part of the cell site;
shaping the radio frequency coverage area of the first marker transmitter so that said zone identification signal can be received by said mobile unit in an area that substantially corresponds to the boundaries of said predefined zone said step of shaping including transmitting a jamming signal from a second marker transmitter at substantially the same time as said zone identification signal is being transmitted from said first marker transmitter to thereby reduce or enlarge the radio frequency coverage area in which the zone identification signal can be received by said mobile unit;
monitoring said marker channel at said mobile unit; and
detecting said zone identification signal at said mobile unit.
9 Assignments
0 Petitions
Accused Products
Abstract
A system for marking a plurality of zones within a cellular service area. One or more marker transmitters are disposed throughout a cellular area to transmit a zone identification signal that is independent of normal RF cellular coverage to a mobile or portable cellular receiver. Each zone identification signal is transmitted in a radio frequency coverage area that illuminates the zone to be identified and is constrained by a similar transmitter jamming the zone signal. The marker transmitters are programmed to transmit the zone identification signal during a predefined time slot so that more than one marker transmitter may simultaneously transmit the zone identification signal, thereby increasing the area in which the zone identification signal can be received by the mobile unit. In order to reduce the area in which a zone identification signal may be received by a mobile unit, the marker transmitters may transmit a jamming signal at the same time as the zone identification signal is transmitted.
185 Citations
34 Claims
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1. A method for marking a predefined zone independent of a cellular telephone system and for determining if a mobile unit is located within the predefined zone, said cellular telephone system including a cell site transceiver that transmits and receives signals to and from a mobile unit on one or more control channels in a cell site, the method comprising the steps of:
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transmitting a zone identification signal on a marker channel that identifies said predefined zone said zone identification signal being transmitted from a first marker transmitter having a radio frequency coverage area that includes at least part of the cell site; shaping the radio frequency coverage area of the first marker transmitter so that said zone identification signal can be received by said mobile unit in an area that substantially corresponds to the boundaries of said predefined zone said step of shaping including transmitting a jamming signal from a second marker transmitter at substantially the same time as said zone identification signal is being transmitted from said first marker transmitter to thereby reduce or enlarge the radio frequency coverage area in which the zone identification signal can be received by said mobile unit; monitoring said marker channel at said mobile unit; and detecting said zone identification signal at said mobile unit. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21)
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22. A zone marker system for use in marking a zone within one or more cell sites of a cellular telephone system that includes a cell site transceiver that transmits and receives signals to and from a mobile telephone unit on one or more control channels in order to provide cellular telephone service within a cell site coverage area, the zone marker system comprising:
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a first marker transmitter for transmitting a zone identification signal on a marker channel wherein the first marker transmitter transmits the zone identification signal in a radio frequency coverage area that includes at least part of the cell site; means for shaping the radio frequency coverage area of the marker transmitter substantially correspond to the boundaries of the zone said shaping means including means for synchronizing a second marker transmitter to simultaneously transmit a jamming signal when a zone identification signal is being transmitted from a first marker transmitter, to thereby reduce or enlarge the radio frequency coverage area in which the zone identification signal can be received by the mobile unit; and means associated with said first marker transmitter for a receiving a signal from said mobile unit that indicates whether the mobile unit has received the zone identification signal. - View Dependent Claims (23, 24, 25, 26, 27, 28)
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29. A mobile unit for use in a cellular telephone system that includes one or more cell site transceivers that transmit signals to and receives signals from the mobile unit on one or more control channels, and a zone marker system that includes a first and a second marker transmitter said first marker transmitter transmitting a zone identification signal on a marker channel in a radio frequency coverage area including at least part of a cell site, said radio frequency coverage area identifying a zone and said second marker transmitter transmitting a jamming signal at the same time as said zone identification signal to thereby reduce or enlarge the radio frequency coverage area, the mobile unit comprising:
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means for monitoring the marker channel to detect the zone identification signal;
in said radio frequency coverage area andmeans for transmitting a signal that indicates the mobile unit is within the zone if the zone identification signal is detected by the mobile unit. - View Dependent Claims (30, 31, 32, 33, 34)
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Specification