US6493539B1
Expired / Lapsed
US
⏱️ 0.0 years remaining
Providing an accurate timing source for locating the geographical position of a mobile
Assignee: Nokia of America Corp
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Filing: 1999-07-28
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Granted: 2002-12-10
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Expires: 2019-07-28
Abstract
Abstract The synchronization system uses a TDMA or AMPS air interface to provide timing synchronization between previously unsynchronized base stations. The synchronization of base stations is critical between when determining the geographical position of a mobile because the geographical position is determined using a time difference of arrival method. In order to synchronize a remote base station with a serving base station, the remote base station receives a signal from the serving base station and measuring the receiving time of the signal at the remote base station in relation to the clock of the remote base station. The synchronization system determines the transmission time of the signal based on the reception time of the signal and the distance between the base stations, in relation to the clock signal of the second station, and synchronizes the clock of the remote base station to the clock of the serving base station based on the offset in the clock cycles at the time the signal was transmitted.
Inventors
- 👤 Steven A. Falco
- 👤 Alex Matusevich
- 👤 Bernard McKay
- 👤 Myles P. Murphy
- 👤 Sheng-Jen Tsai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 17:34
CPC Classifications
H; H04; H04B; H04B7/00; H04B7/14; H04B7/15; H04B7/204; H04B7/212; H04W; H04W56/00; G; G01; G01S; G01S5/00; G01S5/02; G01S5/0205; G01S5/021; G01S5/0226; H04B7/24; H04B7/26; H04B7/2662; H04B7/2671; H04B7/2678; H04B7/2687; H04L; H04L7/00; H04L7/02; H04L7/033; H04W64/00
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
139 words
A method for synchronizing a first base station and a second base station, comprising: (a) receiving a first signal from the first base station, the first base station having a clock signal unsynchronized with a clock signal of the second base station; (b) measuring a receiving time of the first signal in relation to the clock signal of the second base station; (c) determining a transmission time of the first signal based on the measured receiving time of the first signal and a distance between the first base station and the second base station, in relation to the clock signal of the second base station; and (d) synchronizing the clock signal of the second base station to the clock signal of the first base station based on a signal cycle difference between the clock signals at the transmission time.
Claim 2
Independent Claim
139 words
A method for synchronizing a first base station and a second base station, comprising: (a) receiving a first signal from the first base station, the first base station having a clock signal unsynchronized with a clock signal of the second base station; (b) measuring a receiving time of the first signal in relation to the clock signal of the second base station; (c) determining a transmission time of the first signal based on the measured receiving time of the first signal and a distance between the first base station and the second base station, in relation to the clock signal of the second base station; and (d) synchronizing the clock signal of the second base station to the clock signal of the first base station based on a signal cycle difference between the clock signals at the transmission time.
Claim 3
Dependent Claim
53 words
The method of claim 1 , further comprising: (e) receiving a second signal; (f) measuring a receiving time of the second signal in relation to the clock signal of the second station; and (g) determining the difference between the transmission time of the first signal and the receiving time of the second signal.
Claim 4
Dependent Claim
20 words
The method of claim 2 , wherein the second signal is received from a source other than the first station.
Claim 5
Dependent Claim
69 words
The method of claim 1 , further comprising: (e) measuring a predetermined time based on the first signal in relation to the clock signal of the second station; (f) receiving a second signal; (g) measuring a receiving time of the second signal in relation to the clock signal of the second station; and (h) determining a difference between the predetermined time and the receiving time of the second signal.
Claim 6
Dependent Claim
23 words
The method of claim 4 , wherein the predetermined time is indicative of a time when the first station transmits a control message.
Claim 7
Dependent Claim
20 words
The method of claim 4 , wherein the second signal is received from a source other than the first station.
Claim 8
Independent Claim
170 words
A method for synchronizing a first base station and a plurality of second base stations, comprising: (a) transmitting a down link message to the second base stations to synchronize a symbol clock of each of the second base stations to a symbol clock of the first base station; (b) transmitting a control message to the mobile at a predetermined time, the control message requesting a reply message from the mobile; (c) receiving the reply message from the mobile and measuring a time that the reply message was received at the first base station as a first base station receiving time; (d) determining a difference between the predetermined time and the first base station receiving time as a first base station time difference; and (e) receiving messages from the second base stations representing a difference between the predetermined time and a time that the reply message was received at each second base station as a plurality of second base station time differences, so a location of the mobile can be determined.
Claim 9
Independent Claim
170 words
A method for synchronizing a first base station and a plurality of second base stations, comprising: (a) transmitting a down link message to the second base stations to synchronize a symbol clock of each of the second base stations to a symbol clock of the first base station; (b) transmitting a control message to the mobile at a predetermined time, the control message requesting a reply message from the mobile; (c) receiving the reply message from the mobile and measuring a time that the reply message was received at the first base station as a first base station receiving time; (d) determining a difference between the predetermined time and the first base station receiving time as a first base station time difference; and (e) receiving messages from the second base stations representing a difference between the predetermined time and a time that the reply message was received at each second base station as a plurality of second base station time differences, so a location of the mobile can be determined.
Claim 10
Dependent Claim
70 words
The method of claim 7 , prior to step (a), further comprising: (x) transmitting a request message to a plurality of nearby stations to determine a strength of a signal originating from a mobile; (y) receiving response messages from the nearby stations indicating the strength of the signal originating from the mobile; and (z) determining the nearby stations having the strength greater than a predetermined amount as the second stations.
Claim 11
Dependent Claim
47 words
The method of claim 7 , prior to step (a), further comprising: (z) receiving one of a 911 call and a mobile locate call as a mobile locate request, wherein step (a) transmits the down link message to the second stations based on the mobile locate request.
Claim 12
Dependent Claim
25 words
The method of claim 7 , wherein the down link message informs the second station of the predetermined time when the control message is transmitted.
Claim 13
Dependent Claim
137 words
A synchronization system implemented on a computer, comprising: means for receiving a first signal from the first base station, the first base station having a clock signal unsynchronized with a clock signal of the second base station; means for measuring a receiving time of the first signal in relation to the clock signal of the second base station; means for determining a transmission time of the first signal based on the measured receiving time of the first signal and a distance between the first base station and the second base station, in relation to the clock signal of the second base station; and means for synchronizing the clock signal of the second base station to the clock signal of the first base station based on a signal cycle difference between the clock signals at the transmission time.
Claim 14
Dependent Claim
137 words
A synchronization system implemented on a computer, comprising: means for receiving a first signal from the first base station, the first base station having a clock signal unsynchronized with a clock signal of the second base station; means for measuring a receiving time of the first signal in relation to the clock signal of the second base station; means for determining a transmission time of the first signal based on the measured receiving time of the first signal and a distance between the first base station and the second base station, in relation to the clock signal of the second base station; and means for synchronizing the clock signal of the second base station to the clock signal of the first base station based on a signal cycle difference between the clock signals at the transmission time.
Claim 15
Dependent Claim
60 words
The synchronization system of claim 11 , further comprising: subsequent means for receiving a second signal; subsequent means for measuring a receiving time of the second signal in relation to the clock signal of the second station; and subsequent means for determining the difference between the transmission time of the first signal and the receiving time of the second signal.
Claim 16
Dependent Claim
21 words
The synchronization system of claim 11 , wherein the second signal is received from a source other than the first station.
Claim 17
Dependent Claim
80 words
The synchronization system of claim 11 , further comprising: first subsequent means for measuring a predetermined time based on the first signal in relation to the clock signal of the second station; subsequent means for receiving a second signal; second subsequent means for measuring a receiving time of the second signal in relation to the clock signal of the second station; and subsequent means for determining a difference between the predetermined time and the receiving time of the second signal.
Claim 18
Dependent Claim
24 words
The synchronization system of claim 14 , wherein the predetermined time is indicative of a time when the first station transmits a control message.
Claim 19
Dependent Claim
165 words
An executable program embodied on a computer-readable medium for synchronizing a first base station and a second base station, comprising: a receiving source code segment for receiving a first signal from the first base station, the first base station having a clock signal unsynchronized with a clock signal of the second base station; a measuring source code segment for measuring a receiving time of the first signal in relation to the clock signal of the second base station; a determining source code segment for determining a transmission time of the first signal based on the measured receiving time of the first signal and a distance between the first base station and the second base station, in relation to the clock signal of the second base station; and a synchronizing source code segment for synchronizing the clock signal of the second base station to the clock signal of the first base station based on a signal cycle difference between the clock signals at the transmission time.
Claim 20
Dependent Claim
165 words
An executable program embodied on a computer-readable medium for synchronizing a first base station and a second base station, comprising: a receiving source code segment for receiving a first signal from the first base station, the first base station having a clock signal unsynchronized with a clock signal of the second base station; a measuring source code segment for measuring a receiving time of the first signal in relation to the clock signal of the second base station; a determining source code segment for determining a transmission time of the first signal based on the measured receiving time of the first signal and a distance between the first base station and the second base station, in relation to the clock signal of the second base station; and a synchronizing source code segment for synchronizing the clock signal of the second base station to the clock signal of the first base station based on a signal cycle difference between the clock signals at the transmission time.
Claim 21
Dependent Claim
146 words
A computer data signal, comprising: a receiving signal segment for receiving a first signal from the first base station, the first base station having a clock signal unsynchronized with a clock signal of the second base station; a measuring signal segment for measuring a receiving time of the first signal in relation to the clock signal of the second base station; a determining signal segment for determining a transmission time of the first signal based on the measured receiving time of the first signal and a distance between the first base station and the second base station, in relation to the clock signal of the second base station; and a synchronizing signal segment for synchronizing the clock signal of the second base station to the clock signal of the first base station based on a signal cycle difference between the clock signals at the transmission time.
Claim 22
Dependent Claim
146 words
A computer data signal, comprising: a receiving signal segment for receiving a first signal from the first base station, the first base station having a clock signal unsynchronized with a clock signal of the second base station; a measuring signal segment for measuring a receiving time of the first signal in relation to the clock signal of the second base station; a determining signal segment for determining a transmission time of the first signal based on the measured receiving time of the first signal and a distance between the first base station and the second base station, in relation to the clock signal of the second base station; and a synchronizing signal segment for synchronizing the clock signal of the second base station to the clock signal of the first base station based on a signal cycle difference between the clock signals at the transmission time.
References Cited (Backward Citations)
US5410588A
Cited
US5854793A
Cited
US5828659A
Cited
US5668804A
Cited
US6047181A
Cited
US5734985A
Cited
US5633872A
Cited
EP0767594A2
Cited
US6249252B1
Cited
US6236365B1
Cited
US6014376A
Cited
US6125125A
Cited
US6108556A
Cited
WO1998052376A1
Cited
US6223040B1
Cited
US5901358A
Cited
US6021330A
Cited
US6219347B1
Cited
US6307840B1
Cited
US6081229A
Cited
WO1999057826A1
Cited
US6160511A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2005-12-09 | 2006-06-10 | 2006-12-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2009-12-09 | 2010-06-10 | 2010-12-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2013-12-09 | 2014-06-10 | 2014-12-10 | $7700.00 | Window Closed / Lapsed |