Time synchronizing device and process and associated products

• US 20090201936A1
• Filed: 01/03/2005
• Published: 08/13/2009
• Est. Priority Date: 01/09/2004
• Status: Active Grant

• Current Assignee: InterDigital CE Patent Holdings SAS (InterDigital, Inc.)
• Original Assignee: Thomson Licensing (Vantiva SA)
• Inventors: Van De Poel, Dirk, Dumet, Sylvain
• Granted Patent: US 7,804,838 B2
• Time in Patent Office: Days
• US Class Current: 370/401
• CPC Class Codes: H04J 3/0641 Change of the master or reference, e.g. take-over or failure of the master
• CPC Class Codes: H04L 67/02 based on web technology, e.g. hypertext transfer protocol [HTTP]
• CPC Class Codes: H04L 67/56 Provisioning of proxy services store-and-forward switching systems in data switching networks H04L12/54
• CPC Class Codes: H04L 67/563 Data redirection of data network streams
• CPC Class Codes: H04L 67/564 Enhancement of application control based on intercepted application data
• CPC Class Codes: H04L 69/28 Timers or timing mechanisms used in protocols
• CPC Class Codes: H04L 69/329 in the application layer [OSI layer 7]
• CPC Class Codes: H04L 9/40 Network security protocols

Abstract

The present invention concerns a time synchronizing device and process, and a local gateway comprising that device. The time synchronizing device synchronizes a router arranged between two communication networks. It comprises intercepting means of a message coming from an apparatus of a source network for that message, having a specific time clock, and directed to a target network for that message, preparing means of a time request able to be executed in that apparatus so as to cause synchronizing data based on that specific clock to be obtained from that apparatus and to be transmitted back to the synchronizing device, sending means of the time request to the apparatus, forwarding means of the intercepted message to the target network after the preparing means have prepared the time request, receiving means of the synchronizing data, and exploiting means of those data to synchronize a local time clock used by the router with respect to that specific time clock. Application to home networks.

Claims

1. Time synchronizing device for synchronizing a router arranged between two communication networks, said synchronizing device comprising:

receiving means for receiving synchronizing data based on a reference time clock,

and exploiting means for exploiting said synchronizing data (SYNC) so as to synchronize a local time clock used by said router with respect to said reference time clock,

wherein said time synchronizing device comprises;

intercepting means for intercepting at least one message (MSG) coming from at least one apparatus being a point of at least one of said networks, called the source network for said message (MSG), and directed to the other of said networks, called the target network for said message (MSG), said apparatus having a specific time clock,

preparing means for preparing a time request intended for said apparatus, said time request being able to be executed in said apparatus so as to cause said synchronizing data based on said specific time clock to be obtained from said apparatus and to be transmitted back to said synchronizing device,

sending means for sending said time request to said apparatus,

and forwarding means for forwarding said intercepted message (MSG) to said target network after the preparing means have prepared said time request,

said receiving means being intended to receive said synchronizing data from said apparatus and said exploiting means being able to exploit said synchronizing data so as to synchronize said local time clock with respect to said specific time clock, said receiving means, exploiting means, intercepting means, preparing means, sending means and forwarding means forming an operational set.

2. Synchronizing device according to claim 1, wherein said intercepting means are intended to intercept said message and said receiving means are intended to receive and extract said synchronizing data in compliance with the HTTP protocol.

3. Synchronizing device according to claim 1, wherein said preparing means are intended to prepare the time requests in the form of executable scripts, preferably based on the Java language.

4. Synchronizing device according to claim 1, wherein said forwarding means are intended to forward said intercepted message to said target network only after the exploiting means have exploited said synchronizing data obtained from said apparatus by means of said time request.

5. Synchronizing device claim 1, wherein said preparing means are able to prepare said time request for getting at least one of the following synchronizing data time zone and daylight saving time information.

6. Synchronizing device according to claim 1, wherein it comprises updating means for periodically updating said synchronizing data so as to synchronize said local time clock, by periodically activating said operational set, said updating means being preferably intended for using as said intercepted message for each of said updating periods, the first message received from at least one of said communication networks during said period.

7. Synchronizing device according to claim 1, wherein it comprises safety means able to activate said operational set for at least two successive messages from respectively at least two different apparatus, to compare said synchronizing data respectively obtained for said successive messages, to check consistency of said synchronizing data and to trigger a warning mechanism in case of inconsistency.

8. Local gateway intended to be arranged between a LAN and a WAN and to enable communication in both directions between the LAN and the WAN, said local gateway comprising:

a LAN interface for communication with the LAN,

a WAN interface for communication with the WAN,

a local gateway time clock,

and synchronizing means for synchronizing said local gateway time clock with respect to a reference time clock, by means of synchronizing data received by said local gateway,

wherein in that said synchronizing means comprise a time synchronizing device compliant with claim 1 for synchronizing said local gateway, said source and target networks being respectively the LAN (4) and the WAN for all intercepted messages, and said apparatus used for synchronizing being thus at least one point of said LAN.

9. Local gateway according to claim 8, wherein said synchronizing means are also able to synchronize said local gateway time clock with respect to a global time clock available from a timeserver of the WAN.

10. Process for time synchronizing a router arranged between two communication networks, said time synchronizing process comprising the following steps:

receiving synchronizing data based on a reference time clock,

and exploiting said synchronizing data so as to synchronize a local time clock used by said router with respect to said reference time clock,

wherein said time synchronizing process also comprises the following steps;

intercepting at least one message coming from at least one apparatus being a point of at least one of said networks, called the source network for said message, and directed to the other of said networks, called the target network for said message, said apparatus having a specific time clock.

preparing a time request intended for said apparatus, said time request being able to be executed in said apparatus so as to cause said synchronizing data based on said specific time clock to be obtained back from said apparatus,

sending said time request to said apparatus,

and forwarding said intercepted message to said target network after said time request has been prepared,

said receiving step including receiving said synchronizing data from said apparatus and said exploiting step including exploiting said synchronizing data so as to synchronize said local time clock with respect to said specific time clock,

said time synchronizing process being preferably intended to be executed by means of a time synchronizing device compliant with claim 1.

11. Computer program product comprising program code instructions for the execution of the process according to claim 10 when said program is executed on a computer.