Method for accurate time setting of communication device over the air and corresponding communication device

• US 8,000,696 B2
• Filed: 02/23/2007
• Issued: 08/16/2011
• Est. Priority Date: 03/22/2006
• Status: Expired due to Fees

• Current Assignee: Itron Metering Solutions UK Ltd. (Itron, Inc.)
• Original Assignee: Actaris SAS (Itron, Inc.)
• Inventors: Robins, Mark
• Primary Examiner(s): MEHRPOUR, NAGHMEH
• Application Number:
  US11/710,603
• Publication Number:
  US 20070238456A1
• Time in Patent Office: 1,635 Days
• Field of Search: 455/422.1, 455/436, 455/550.1, 455/466, 455/418, 455/437, 455/414.1, 370/503, 370/507, 370/508, 370/509, 370/510, 370/511, 370/512, 370/513, 370/514, 370515-520, 370/340
• US Class Current: 455/422.1
• CPC Class Codes: G01D 4/002 Remote reading of utility meters
• CPC Class Codes: H04J 3/0682 by delay compensation, e.g. by compensation of propagation delay or variations thereof, by ranging
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 56/0015 one node acting as a reference for the others
• CPC Class Codes: H04W 84/042 Public Land Mobile systems, e.g. cellular systems
• CPC Class Codes: Y02B 90/20 Smart grids as enabling technology in buildings sector smart grids supporting the management or operation of end-user stationary applications in general, or like technologies with no associated climate change mitigation effect Y04S20/00
• CPC Class Codes: Y04S 20/30 Smart metering, e.g. specially adapted for remote reading

Abstract

A method for accurate time setting of a communication device (2, 3) in which said communication device (2, 3) sends (A0) a request for time synchronization to a central communications unit (1) through communication data packets via a cellular telephone network (5); said central communications unit (1) sends current time in a response to said communication device (2, 3) through communication data packets via the cellular telephone network (5); said communication device (2, 3) measures (A2) an elapsed time (T) from sending said request to receiving the response and compares said measured elapsed time (T) with a predetermined first configuration parameter (“Trip”); and, When said measured elapsed time (T) is less than said first configuration parameter (“Trip”), said communication device (2, 3) uses (A3) received current time for updating its own time reference.

Claims

1. A method for accurate time setting of a communication device comprising the steps of:

sending a request for time synchronization from said communication device to a central communications unit through communication data packets via a cellular telephone network;

sending current time from said central communications unit in a response to said communication device through communication data packets via the cellular telephone network; and

measuring an elapsed time at said communication device from sending said request to receiving the response and comparing said measured elapsed time with a predetermined first configuration parameter,

wherein when said measured elapsed time is less than said first configuration parameter, said communication device uses received current time for updating its own time reference.

2. A method according to claim 1, wherein said received current time is disregarded when said measured elapsed time is greater than said first configuration parameter.

3. A method according to claim 1, wherein a new request for time synchronization is sent as long as the total number of requests is not equal to a second predetermined configuration parameter and said measured elapsed time is greater than or equal to said first configuration parameter.

4. A method according to claim 1, wherein the request and response are sent using GPRS.

5. A method according to claim 1, wherein the request and response are sent using SMS.

6. A communication device comprising:

means for sending a request for time synchronization to a central communications unit through communication data packets via a cellular telephone network;

means for receiving current time in a response from said central communications unit through communication data packets via the cellular telephone network;

means for measuring an elapsed time from sending said request to receiving the response and comparing said measured elapsed time with a predetermined first configuration parameter; and

means for updating the communication device'"'"'s own time reference using received current time when said measured elapsed time is less than said first configuration parameter.

7. A communication device according to claim 6, wherein said means for sending a request and for receiving a response comprise a GPRS/SMS interface.

8. A communication device according to claim 6, wherein the device is used as utility meter.

9. A communication device according to claim 6, wherein the device is used as utility meter interface unit linked to several utility meters.