Method and apparatus for enhanced 911 location using power control in a wireless system
First Claim
1. A method of locating a mobile telephone, comprising the steps of:
- receiving at a base station a call from a mobile telephone, the call including a dialed number and a TDMA signal;
transmitting from the base station to the mobile telephone a control message, in response to the dialed number meeting a predetermined criterion, the control message instructing the mobile telephone to transmit the TDMA signal at a maximum power;
increasing the TDMA signal to maximum power in response to the control message; and
determining location information for the mobile telephone based on at least one characteristic of the TDMA signal received at the base station.
9 Assignments
0 Petitions
Accused Products
Abstract
A method of locating a mobile telephone includes steps of receiving, transmitting, increasing and determining. In the receiving step, a first base station receives a call from a mobile telephone, the call including a dialed number and a TDMA signal. In the transmitting step, the base station transmits a control message to the mobile telephone when the dialed number meets a predetermined criterion, such as being 911. The control message instructs the mobile telephone to transmit the TDMA signal at a maximum power. In the increasing step, the mobile telephone increases the TDMA signal to maximum power in response to the control message. Then in the determining step, location information for the mobile telephone is determined based on at least one characteristic of the TDMA signal received at at least one of the first base station and other base stations. In an alternate embodiment, the method is practiced in a mobile telephone and the power level is automatically increased in response to the dialed number meeting a predetermined criterion.
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Citations
25 Claims
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1. A method of locating a mobile telephone, comprising the steps of:
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receiving at a base station a call from a mobile telephone, the call including a dialed number and a TDMA signal;
transmitting from the base station to the mobile telephone a control message, in response to the dialed number meeting a predetermined criterion, the control message instructing the mobile telephone to transmit the TDMA signal at a maximum power;
increasing the TDMA signal to maximum power in response to the control message; and
determining location information for the mobile telephone based on at least one characteristic of the TDMA signal received at the base station. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
receiving a MIN from the mobile telephone;
querying a user profile database with the MIN to determine whether the location function should be invoked; and
invoking location function based on the query.
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5. The method according to claim 1, further comprising:
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receiving a dialed number from the mobile telephone; and
invoking the location function when the dialed number meets a predetermined criterion.
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6. The method according to claim 1, further comprising:
determining location information for the mobile telephone based on pre-specified data comprised by the TDMA signal received at the base station, the pre-specified data selected to assist in location determination.
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7. The method according to claim 6, further comprising:
providing the location information to a recipient of the call.
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8. The method according to claim 7, further comprising:
providing the location information to a geographic information system for displaying the location information on a map.
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9. A method of locating a mobile telephone, comprising:
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receiving at a base station a signal from a mobile telephone;
invoking a location function in response to the signal;
determining whether the mobile telephone should increase power for location determination;
transmitting from the base station to the mobile telephone a control message instructing the mobile telephone to transmit a TDMA signal at an increased power level based on the determining;
receiving at least one of a plurality of base stations the TDMA signal transmitted at the increased power level; and
calculating a location of the mobile telephone based on the TDMA signal received at at least one of the plurality of base stations. - View Dependent Claims (10, 11, 12, 13, 22)
receiving a MIN from the mobile telephone;
querying a user profile database with the MIN to determine whether the location function should be invoked; and
invoking location function based on the query.
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13. The method according to claim 9, further comprising:
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receiving a dialed number from the mobile telephone; and
invoking the location function when the dialed number meets a predetermined criterion.
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22. The method of claim 9, further comprising:
calculating a location of the mobile telephone based at least in part on pre-specified data comprised by the TDMA signal received at at least one of the plurality of base stations, the pre-specified data selected to assist in location determination.
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14. A method of locating a mobile telephone, comprising:
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receiving a dialed number in a first signal having a first power level;
determining whether the dialed number triggers a location function;
initiating a mobile telephone call to the dialed number;
transmitting known data to a mobile telephone system for location determination at increased power level when the location function is determined to be triggered;
receiving in response to the known data a second signal from the mobile telephone, the second signal having a higher power level than the first signal, the second signal comprising pre-specified data to assist in location determination; and
applying the higher power level of the second signal to perform the location determination triggered by receipt of the dialed number. - View Dependent Claims (15, 16)
receiving location data from the mobile telephone system; and
displaying the location data on the mobile telephone.
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16. The method according to claim 14, further comprising:
decreasing the power level after location determination.
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17. An apparatus for locating a mobile telephone, comprising:
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a plurality of base stations communicating TDMA signals with a mobile telephone;
a mobile switching center, coupled with the plurality of base stations, the mobile switching center a) receiving from one of the plurality of base stations a call that includes a dialed number of the mobile telephone, b) determining whether the dialed number invokes a location function, and c) sending an instruction to the mobile telephone via one of the plurality of base stations to increase transmission power when the location function is invoked; and
a location processor, coupled with the plurality of base stations and the mobile switching center, the location processor determining the location of the mobile telephone based on the TDMA signals received from the mobile telephone via at least one of the plurality of base stations at the increased power level. - View Dependent Claims (18, 19, 20, 21)
a geographic information system, coupled with the location processor, the geographic information system receiving the location from the location processor and plotting the location on a map.
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19. The apparatus according to claim 17, further comprising:
a public switched telephone network, coupled to the mobile switching center, for transmitting a call to a destination telephone corresponding to the dialed number.
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20. The apparatus according to claim 17, wherein the mobile switching center further determines whether the call invokes the location function based on a mobile identification number received from the mobile telephone.
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21. The apparatus of claim. 17, the location processor determining the location of the mobile telephone based at least in part on pre-specified data comprised by the TDMA signals received from the mobile telephone, the pre-specified data selected to assist in location determination.
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23. A method comprising:
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instructing a mobile device to place a call;
the mobile device determining whether location determination is to be performed for the call;
the mobile device transmitting the call at a highest power level available for calls from the mobile device when location determination is to be performed for the call, the mobile device transmitting the call at a lower power level otherwise; and
the mobile device transmitting pre-specified data during the call when the call is transmitted at a highest power level, the pre-specified data selected to assist in location determination.
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24. A method of locating a mobile telephone, comprising:
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receiving at a first base station a request from a mobile device to perform location determination for the mobile device;
invoking a location function in response to the signal;
determining whether the mobile device should increase power for location determination;
when the mobile device should increase power, transmitting from the base station to the mobile device a control message instructing the mobile device to transmit a signal at a highest power level;
receiving at at least one of a plurality of base stations the highest power level; and
calculating a location of the mobile device based on the signal received at the at least one of the plurality of base stations, the signal comprising pre-specified data selected to assist in location determination.
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25. An apparatus for locating a mobile telephone, comprising:
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a plurality of base stations communicating signals with a mobile telephone;
a mobile switching center, coupled with the plurality of base stations, the mobile switching center a) receiving from one of the plurality of base stations a call that includes a dialed number of the mobile telephone, b) determining whether the dialed number invokes a location function, and c) sending an instruction to the mobile telephone via one of the plurality of base stations to increase transmission power and to provide pre-specified data when the location function is invoked; and
a location processor, coupled with the plurality of base stations and the mobile switching center, the location processor determining the location of the mobile telephone based at least in part on the pre-specified data received from the mobile telephone via at least one of the plurality of base stations at the increased power level.
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Specification