METHODS AND DEVICES FOR PERFORMING SYNCHRONIZATION AND COMPENSATING CLOCK DRIFT AMONG COMMUNICATION DEVICES

• US 20130010781A1
• Filed: 07/03/2012
• Published: 01/10/2013
• Est. Priority Date: 07/04/2011
• Status: Active Grant

• Current Assignee: Mitsubishi Electric Corporation
• Original Assignee: Mitsubishi Electric Corporation
• Inventors: GRESSET, Nicolas, Letessier, Jonathan
• Granted Patent: US 8,737,379 B2
• Time in Patent Office: Days
• US Class Current: 370/350
• CPC Class Codes: H04J 3/0605 Special codes used as synchronising signal
• CPC Class Codes: H04J 3/0652 Synchronisation among time division multiple access [TDMA] nodes, e.g. time triggered protocol [TTP] bus network with centralized control in which slots are of a TDMA packet structure H04L12/4035

Abstract

In order to perform synchronization and compensate clock drift among a plurality of communication devices interconnected to form a mesh communications network, all communication devices, except one given communication device, perform a first distributed consensus-based synchronization. The given communication device performs: obtaining a first correction information derived at least from a difference between a clock timing resulting from the first distributed consensus-based synchronization and a reference clock timing; and transmitting the first correction information through the mesh communications network. All the communication devices, except said given communication device, further perform updating the clock timing resulting from the first distributed consensus-based synchronization by taking into account the transmitted first correction information.

Claims

1. A method for performing synchronization and compensating clock drift among a plurality of communication devices interconnected to form a mesh communications network,

wherein all said communication devices, except one given communication device, perform a first distributed consensus-based synchronization;

and wherein said given communication device performs;

obtaining a first correction information derived at least from a difference between a clock timing resulting from the first distributed consensus-based synchronization and a reference clock timing; and

transmitting the first correction information through the mesh communications network;

and wherein all said communication devices, except said given communication device, further perform;

updating the clock timing resulting from the first distributed consensus-based synchronization by taking into account the transmitted first correction information.

2. The method according to claim 1, wherein said given communication device obtains the first correction information from at least one clock timing derived from synchronization signals received from at least one respective communication device when performing the first distributed consensus-based synchronization.

3. The method according to claim 1, wherein said given communication device obtains the first correction information from a server device and said given communication device performs:

obtaining a local correction information from one clock timing derived from synchronization signals received from at least one respective communication device when performing the distributed consensus-based synchronization; and

transmitting the local correction information to the server device;

and wherein, the server device being connected to multiple groups of communication devices interconnected to form respective mesh communications networks, said server device performs;

receiving a local correction information from one communication device of each said group;

combining the received local correction information to obtain said first correction information.

4. The method according to claim 1, wherein, said given communication device being interconnected with at least one group of communication devices interconnected to form at least one other respective mesh communications networks, said given communication device performs:

obtaining a local correction information from one clock timing derived from synchronization signals received from at least one respective communication device when performing the first distributed consensus-based synchronization and the reference clock;

transmitting the local correction information to one communication device of each said another group;

receiving another local correction information from said communication device of each said another group; and

combining the received local correction information to obtain said first correction information.

5. The method according to claim 1, wherein, said given communication device being interconnected with plural groups of communication devices interconnected to form plural respective other mesh communications networks,

a set of communication devices performs a second distributed consensus-based synchronization, said set being formed by one communication device for each said other mesh communications network;

and said given communication device performs;

obtaining a second correction information derived at least from a difference between a clock timing resulting from the second distributed consensus-based synchronization and the reference clock timing; and

transmitting the second correction information to said set of communication devices;

and said set of communication devices further performs;

updating the clock timing resulting from the second distributed consensus-based synchronization by taking into account the transmitted second correction information.

6. The method according to claim 1, wherein said given communication device obtains the first correction information from at least one clock timing derived from synchronization signals received from at least one respective communication device when performing the first distributed consensus-based synchronization and from at least one other clock timing derived from other synchronization signals received from said at least one respective communication device when performing another distributed consensus-based synchronization.

7. The method according to claim 6, wherein said given communication device adjusts the reference clock timing from the at least one clock timing derived from synchronization signals received from said at least one respective communication device when performing the first distributed consensus-based synchronization and from the at least one other clock timing derived from other synchronization signals received from said at least one respective communication device when performing said another distributed consensus-based synchronization.

8. A system for performing synchronization and compensating clock drift among a plurality of communication devices interconnected to form a mesh communications network,

wherein all said communication devices, except one given communication device, comprise means for performing a first distributed consensus-based synchronization;

and wherein said given communication device comprises;

means for obtaining a first correction information derived at least from a difference between a clock timing resulting from the first distributed consensus-based synchronization and a reference clock timing;

means for transmitting the first correction information through the mesh communications network;

and wherein all said communication devices, except said given communication device, further comprise;

means for updating the clock timing resulting from the first distributed consensus-based synchronization by taking into account the transmitted first correction information.

9. A method for performing synchronization and compensating clock drift among a plurality of communication devices interconnected to form a mesh communications network,

wherein a given communication device performs:

obtaining a first correction information derived at least from a difference between a clock timing resulting from a first distributed consensus-based synchronization and a reference clock timing, the first distributed consensus-based synchronization being performed by all said communication devices, except said given communication device; and

transmitting the first correction information through the mesh communications network, the transmitted first correction information aiming all said communication devices, except said given communication device, at updating the clock timing resulting from the first distributed consensus-based synchronization.

10. A communication device for performing synchronization and compensating clock drift among a plurality of communication devices interconnected to form a mesh communications network,

wherein said communication device comprises:

means for obtaining a first correction information derived at least from a difference between a clock timing resulting from a first distributed consensus-based synchronization and a reference clock timing, the first distributed consensus-based synchronization being performed by all said communication devices, except the claimed communication device;

means for transmitting the first correction information through the mesh communications network, the transmitted first correction information aiming all said communication devices, except said given communication device, at updating the clock timing resulting from the first distributed consensus-based synchronization.

11. A method for performing synchronization and compensating clock drift, the method being performed by a server device connected to multiple groups of communication devices interconnected to form respective mesh communications networks, wherein said server device performs:

receiving a local correction information from one communication device of each said group, said local correction information being obtained from one clock timing derived from synchronization signals received from at least one respective communication device when performing the first distributed consensus-based synchronization and the reference clock;

combining the received local correction information to obtain a first correction information; and

transmitting the first correction information to said one communication device of each said group.

12. A server device for performing synchronization and compensating clock drift, the server device aiming at being connected to multiple groups of communication devices interconnected to form respective mesh communications networks, wherein said server device comprises:

means for receiving a local correction information from one communication device of each said group, said local correction information being obtained from one clock timing derived from synchronization signals received from at least one respective communication device when performing a first distributed consensus-based synchronization and the reference clock;

means for combining the received local correction information to obtain a first correction information;

means for transmitting the first correction information to said one communication device of each said group, the transmitted first correction information aiming said one communication device of each said group at allowing updating the clock timing resulting from the first distributed consensus-based synchronization.

13. A method for performing synchronization and compensating clock drift among a plurality of communication devices interconnected to form a mesh communications network, wherein a considered communication device performs, in collaboration with all said communication devices except one given communication device, a first distributed consensus-based synchronization;

receiving a first correction from said given communication device, said first correction information being derived at least from a difference between a clock timing resulting from a first distributed consensus-based synchronization and a reference clock timing; and

updating the clock timing resulting from the first distributed consensus-based synchronization by taking into account the received first correction information, the transmitted first correction information aiming said one communication device of each said group at allowing updating the clock timing resulting from the first distributed consensus-based synchronization.

14. A communication device for performing synchronization and compensating clock drift among a plurality of communication devices interconnected to form a mesh communications network, wherein the claimed communication device comprises:

means for performing, in collaboration with all said communication devices except one given communication device, a first distributed consensus-based synchronization;

means for receiving a first correction from said given communication device, said first correction information being derived at least from a difference between a clock timing resulting from the first distributed consensus-based synchronization and a reference clock timing;

means for updating the clock timing resulting from the first distributed consensus-based synchronization by taking into account the received first correction information.