US5293645A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus and method for locating mobile and portable radio terminals in a radio network
Assignee: Sharp Corp
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Filing: 1991-10-04
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Granted: 1994-03-08
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Expires: 2011-10-04
Abstract
Abstract A system for locating a movable radio terminal within a cellular telephone network, or other radio network, which includes a plurality of base stations that transmit synchronized timing reference signals. A receiver in the network receives transmissions from the radio terminals to be located that include information compiled at the radio terminal indicating relative propagation delays in receipt of the timing reference signals from at least three base stations. A processor coupled with the receiver, processes the transmissions indicating relative propagation delays to identify a geographic location of the radio terminal. A complementary radio terminal receives the timing reference signals from base stations, including a designated base station and compiles information indicating propagation delays, relative to the propagation delay of the timing reference signal from the designated base station, from at least two additional base stations. The radio terminal transmits the information compiled so that a station receiving the transmission may locate the radio terminal in response to the information and the known locations of base stations in the network.
Inventors
- 👤 Prem L. Sood
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 21:21
CPC Classifications
H; H04; H04W; H04W64/00; G; G01; G01S; G01S5/00; G01S5/02; G01S5/0205; G01S5/021; G01S5/0226; G01S5/14
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
173 words
An apparatus for locating a radio terminal in a radio network, comprising: a plurality of base station in the radio network, each including a transmitter and a receiver communicating with the radio terminal if the radio terminal is located within an operating range of one of the plurality of base stations and transmitting a timing reference signal substantially synchronized with the timing reference signals transmitted by other base stations in the plurality of base stations, wherein the radio terminals includes a processor for compiling information indicating relative propagation delays of the timing reference signals from at least three base stations in the plurality of base stations; means, in the radio network, for receiving transmissions from the radio terminal to be located, the transmissions including the information compiled at the radio terminal indicating the relative propagation delays in receipt of the timing reference signals by the radio terminal; and means coupled with the means for receiving, for processing the transmissions indicating the relative propagation delays to identify a geographic location of the radio terminal.
Claim 2
Independent Claim
173 words
An apparatus for locating a radio terminal in a radio network, comprising: a plurality of base station in the radio network, each including a transmitter and a receiver communicating with the radio terminal if the radio terminal is located within an operating range of one of the plurality of base stations and transmitting a timing reference signal substantially synchronized with the timing reference signals transmitted by other base stations in the plurality of base stations, wherein the radio terminals includes a processor for compiling information indicating relative propagation delays of the timing reference signals from at least three base stations in the plurality of base stations; means, in the radio network, for receiving transmissions from the radio terminal to be located, the transmissions including the information compiled at the radio terminal indicating the relative propagation delays in receipt of the timing reference signals by the radio terminal; and means coupled with the means for receiving, for processing the transmissions indicating the relative propagation delays to identify a geographic location of the radio terminal.
Claim 3
Dependent Claim
34 words
The apparatus of claim 1, including an additional base station having a transmitter and a receiver in the radio network, and wherein the means for receiving comprises the receiver in the additional base station.
Claim 4
Dependent Claim
36 words
The apparatus of claim 1, further including: means mounted in respective base stations in the plurality of base stations, for synchronizing the timing reference signal of the respective base station with a master timing reference signal.
Claim 5
Dependent Claim
67 words
The apparatus of claim 1, wherein the means for processing includes: means, responsive to the information indicating relative propagation delays, for determining estimated propagation distances to the radio terminal from at least three base stations in the plurality of base stations; and means, responsive to the estimated propagation distances and known locations of the plurality of base stations, for identifying the geographic location for the radio terminal.
Claim 6
Dependent Claim
51 words
The apparatus of claim 1, further including: means for supplying a master timing reference signal to the plurality of base stations; and means, mounted in respective base stations in the plurality of base stations, for synchronizing the timing reference signal of the respective base station with the master timing reference signal.
Claim 7
Dependent Claim
21 words
The apparatus of claim 5, wherein the means for supplying includes a direct communication link to the plurality of base stations.
Claim 8
Independent Claim
183 words
An apparatus for locating a radio terminal in a radio network, comprising: a plurality of base stations, each including a transmitter transmitting a timing reference signal, wherein the radio terminal includes a processor for compiling information indicating relative propagation delays of the timing reference signals from at least three base stations in the plurality of base stations; means for supplying a master timing reference signal to the plurality of base stations; means mounted in respective base stations in the plurality of base stations, for synchronizing the timing reference signal of the respective base station with the master timing reference signal; a receiver in the plurality of base stations, adapted to receive transmissions from the radio terminal to be located, the transmissions including the information compiled at the radio terminal indicating the relative propagation delays of the timing reference signals by the radio terminal, relative to the propagation delay from a designated base station in the plurality of base stations; and means coupled with the receiver, for processing the transmissions indicating the relative propagation delays to identify a geographic location of the radio terminal.
Claim 9
Independent Claim
183 words
An apparatus for locating a radio terminal in a radio network, comprising: a plurality of base stations, each including a transmitter transmitting a timing reference signal, wherein the radio terminal includes a processor for compiling information indicating relative propagation delays of the timing reference signals from at least three base stations in the plurality of base stations; means for supplying a master timing reference signal to the plurality of base stations; means mounted in respective base stations in the plurality of base stations, for synchronizing the timing reference signal of the respective base station with the master timing reference signal; a receiver in the plurality of base stations, adapted to receive transmissions from the radio terminal to be located, the transmissions including the information compiled at the radio terminal indicating the relative propagation delays of the timing reference signals by the radio terminal, relative to the propagation delay from a designated base station in the plurality of base stations; and means coupled with the receiver, for processing the transmissions indicating the relative propagation delays to identify a geographic location of the radio terminal.
Claim 10
Dependent Claim
21 words
The apparatus of claim 7, wherein the means for supplying includes a direct communication link to the plurality of base stations.
Claim 11
Dependent Claim
73 words
The apparatus of claim 7, wherein the means for processing includes: means, responsive to the information indicating relative propagation delays, for determining estimated propagation distances to the radio terminal from the designated base station, and at least two additional base stations in the plurality of base stations; and means, responsive to the estimated propagation distances and known locations of the plurality of base stations, for identifying the geographic location for the radio terminal.
Claim 12
Dependent Claim
146 words
For use in a radio network including a plurality of base stations transmitting synchronized timing reference signals, a radio terminal comprising: a receiver receiving the timing reference signals from base stations in the plurality of base stations, including a designated base station, in a region near the receiver; means coupled with the receiver, for compiling information indicating propagation delays, relative to the propagation delay of the timing reference signal from the designated base station, of the timing reference signals from at least two additional base stations in the plurality of base stations in the region near the receiver; and a transmitter, coupled with the means for compiling, for transmitting information indicating the relative propagation delays of the timing reference signals, so that the radio terminal may be located in response to the transmission and known locations of the base stations in the plurality of base stations.
Claim 13
Dependent Claim
146 words
For use in a radio network including a plurality of base stations transmitting synchronized timing reference signals, a radio terminal comprising: a receiver receiving the timing reference signals from base stations in the plurality of base stations, including a designated base station, in a region near the receiver; means coupled with the receiver, for compiling information indicating propagation delays, relative to the propagation delay of the timing reference signal from the designated base station, of the timing reference signals from at least two additional base stations in the plurality of base stations in the region near the receiver; and a transmitter, coupled with the means for compiling, for transmitting information indicating the relative propagation delays of the timing reference signals, so that the radio terminal may be located in response to the transmission and known locations of the base stations in the plurality of base stations.
Claim 14
Independent Claim
115 words
A method for locating a movable radio terminal in a radio network including a plurality of base stations transmitting timing reference signals, comprising: synchronizing the timing reference signals in the plurality of base stations; receiving a transmission from the movable radio terminal including information indicating relative propagation delays of the timing reference signals from at least three base stations to the movable radio terminal; processing the information to determine estimated propagation distances to the movable radio terminal from at least three base stations in the plurality of base stations; and locating the movable radio terminal in response to the estimated propagation distance and known locations of the base stations in the plurality of base stations.
Claim 15
Independent Claim
115 words
A method for locating a movable radio terminal in a radio network including a plurality of base stations transmitting timing reference signals, comprising: synchronizing the timing reference signals in the plurality of base stations; receiving a transmission from the movable radio terminal including information indicating relative propagation delays of the timing reference signals from at least three base stations to the movable radio terminal; processing the information to determine estimated propagation distances to the movable radio terminal from at least three base stations in the plurality of base stations; and locating the movable radio terminal in response to the estimated propagation distance and known locations of the base stations in the plurality of base stations.
Claim 16
Dependent Claim
33 words
The method of claim 11, wherein the step of synchronizing comprises: synchronizing the timing reference signals of the respective base stations in the plurality of base stations with a master timing reference signal.
Claim 17
Dependent Claim
46 words
The method of claim 11, wherein the step of synchronizing comprises: supplying a master timing reference signal to the plurality of base stations; and synchronizing the timing reference signals of the respective base stations in the plurality of base stations with the master timing reference signal.
Claim 18
Dependent Claim
115 words
For a radio network including a plurality of base stations transmitting synchronized timing reference signals, a method for providing information from a movable radio terminal from which its location may be identified, comprising: receiving, at the movable radio terminal, the timing reference signals from at least three base stations in the plurality of base stations; identifying, at the movable radio terminal, a designated base station in the plurality of base stations; determining, at the movable radio terminal, propagation delays of the received timing reference signals relative to the time of receipt of the timing reference signal from the designated base station; and transmitting, from the movable radio terminal, the information indicating the relative propagation delays.
Claim 19
Dependent Claim
115 words
For a radio network including a plurality of base stations transmitting synchronized timing reference signals, a method for providing information from a movable radio terminal from which its location may be identified, comprising: receiving, at the movable radio terminal, the timing reference signals from at least three base stations in the plurality of base stations; identifying, at the movable radio terminal, a designated base station in the plurality of base stations; determining, at the movable radio terminal, propagation delays of the received timing reference signals relative to the time of receipt of the timing reference signal from the designated base station; and transmitting, from the movable radio terminal, the information indicating the relative propagation delays.
Claim 20
Independent Claim
152 words
An apparatus for locating a radio terminal in a radio network, comprising: a plurality of base stations for the radio network, each including a transmitter transmitting a timing reference signal substantially synchronized with the timing reference signals transmitted by other base stations in the plurality of base stations, wherein the radio terminal includes a processor for compiling information indicating relative propagation delays of the timing reference signals from at least three base stations in the plurality of base stations; a receiver, mounted in at least one base station in the plurality of base stations, to receive transmissions from the radio terminal to be located, the transmissions including the information compiled at the radio terminal indicating relative propagation delays in receipt of the timing reference signals by the radio terminal; and means, coupled with the receiver, for processing the transmissions indicating the propagation delays to identify a geographic location of the radio terminal.
Claim 21
Independent Claim
152 words
An apparatus for locating a radio terminal in a radio network, comprising: a plurality of base stations for the radio network, each including a transmitter transmitting a timing reference signal substantially synchronized with the timing reference signals transmitted by other base stations in the plurality of base stations, wherein the radio terminal includes a processor for compiling information indicating relative propagation delays of the timing reference signals from at least three base stations in the plurality of base stations; a receiver, mounted in at least one base station in the plurality of base stations, to receive transmissions from the radio terminal to be located, the transmissions including the information compiled at the radio terminal indicating relative propagation delays in receipt of the timing reference signals by the radio terminal; and means, coupled with the receiver, for processing the transmissions indicating the propagation delays to identify a geographic location of the radio terminal.
Claim 22
Dependent Claim
36 words
The apparatus of claim 15, further including: means, mounted in respective base stations in the plurality of base stations, for synchronizing the timing reference signal of the respective base station with a master timing reference signal.
Claim 23
Dependent Claim
66 words
The apparatus of claim 15, wherein the means for processing includes: means, responsive to the information indicating relative propagation delays, for determining estimated propagation distances to the terminal from at least three base stations in the plurality of base stations; and means, responsive to the estimated propagation distances and known locations of the plurality of base stations, for identifying the geographic location for the radio terminal.
Claim 24
Dependent Claim
51 words
The apparatus of claim 15, further including: means for supplying a master timing reference signal to the plurality of base stations; and means, mounted in respective base stations in the plurality of base stations, for synchronizing the timing reference signal of the respective base station with the master timing reference signal.
Claim 25
Dependent Claim
21 words
The apparatus of claim 18, wherein the means for supplying includes a direct communication link to the plurality of base stations.
Claim 26
Dependent Claim
16 words
The apparatus of claim 1, wherein the plurality of base stations comprise a cellular radio network.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-03-07 | 1997-09-06 | 1998-03-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-03-07 | 2001-09-06 | 2002-03-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-03-07 | 2005-09-06 | 2006-03-08 | $7700.00 | Window Closed / Lapsed |