SYSTEM AND METHOD FOR PROVIDING TIME TO A SATELLITE POSITIONING SYSTEM (SPS) RECEIVER FROM A NETWORKED TIME SERVER
First Claim
1. A method for providing time information comprising:
- sending a query to a time server via a first communications network;
determining a time-of-day from a response from the time server;
adjusting a clock if the time-of-day differs from a time maintained by the clock; and
providing the time information to a satellite positioning system (SPS) receiver via a first communications link, wherein the communications link is different from a second communications link that is used by satellites in the SPS to transmit information to the SPS receiver.
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Accused Products
Abstract
System and method for enabling signal acquisition in a satellite positioning system (SPS) when signals from SPS satellites are attenuated by the operating environment of a SPS receiver. A preferred embodiment comprises a communications server (for example, communications server 220) coupled to a SPS receiver (for example, SPS receiver 210) at one end and a time server (for example, time server 225) by a public network (for example, the Internet 230). Preferably, the communications server 220 is coupled to the Internet 230 via a wireless network to facilitate maximum mobility and flexibility. The communications server 220 queries the time server 225 for the current time and then provides the current time to the SPS receiver 210. The SPS receiver 210 makes use of the current time to assist it in signal acquisition.
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Citations
47 Claims
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1. A method for providing time information comprising:
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sending a query to a time server via a first communications network;
determining a time-of-day from a response from the time server;
adjusting a clock if the time-of-day differs from a time maintained by the clock; and
providing the time information to a satellite positioning system (SPS) receiver via a first communications link, wherein the communications link is different from a second communications link that is used by satellites in the SPS to transmit information to the SPS receiver. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A method for facilitating signal acquisition in a satellite positioning system (SPS) comprising:
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sending a periodic query with a first period to a time server via a communications network;
determining a time-of-day from a response from the time server;
adjusting a clock if the time-of-day differs from a time maintained by the clock; and
providing a time information based on the time maintained in the clock periodically to a SPS receiver with periodicity equal to a second period via a first communications link, wherein the first communications link is different from a second communications link that is used by satellites in the SPS to transmit information to the SPS receiver. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18)
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19. A system for aiding signal acquisition in a satellite positioning system (SPS) comprising:
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a SPS receiver, the SPS receiver containing circuitry to receive transmissions from a plurality of SPS satellites and compute its current position and a current time from the received transmissions;
a communications processor coupled to the SPS receiver, the communications processor containing circuitry to obtain time information from an external source and to provide the time information to the SPS receiver;
a first communications network coupled to the communications processor; and
a time server coupled to the first communications network, the time server containing circuitry to maintain accurate time and to response to time queries. - View Dependent Claims (20, 21, 22, 23, 24, 25, 26, 27, 28, 29)
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30. A position measuring device comprising:
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a satellite positioning system (SPS) receiver comprising an analog processing unit containing circuitry to filter and amplify an analog SPS signal received via an antenna;
a digital processing unit coupled to the analog processing unit, the digital processing unit containing circuitry to perform signal acquisition, correlation, and decode;
a communications processor comprising a pulse and message generator (PMG) unit containing circuitry to produce a timing beacon and a timing message;
a real-time clock coupled to the PMG unit, the real-time clock containing circuitry to keep track of time and to generate signals to indicate timing events; and
a network client coupled to the real-time clock, the network client containing circuitry to receive timing information from a time server coupled to the communications processor via a network and to provide time adjustments to the real-time clock. - View Dependent Claims (31, 32, 33, 34, 35)
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36. A communications processor comprising:
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a pulse and message generator (PMG) containing circuitry to produce a timing beacon and a timing message for use by a satellite positioning system receiver;
a real-time clock coupled to the PMG, the real-time clock containing circuitry to track time and to generate signals to indicate timing events to the PMG; and
a network client coupled to the real-time clock, the network client containing circuitry to receive timing information from a time server coupled to the communications processor via a network and to provide time adjustments to the real-time clock. - View Dependent Claims (37, 38, 39, 40, 41, 42)
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43. A method for facilitating signal acquisition in a satellite positioning system (SPS) comprising;
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determining a time-of-day from a time message broadcast by a time server;
adjusting a clock if the time-of-day differs from a time maintained by the clock; and
providing a time information based on the time maintained in the clock periodically to a SPS receiver via a first communications link, wherein the first communications link is different from a second communications link that is used by satellites in the SPS to transmit information to the SPS receiver. - View Dependent Claims (44, 45, 46, 47)
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Specification