METHOD AND SYSTEM FOR ENERGY EFFICIENT SYNCHRONIZATION IN PACKET BASED NETWORKS

• US 20110142080A1
• Filed: 01/20/2010
• Published: 06/16/2011
• Est. Priority Date: 12/16/2009
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Diab, Wael
• Granted Patent: US 8,340,010 B2
• Time in Patent Office: Days
• US Class Current: 370/503
• CPC Class Codes: H04J 3/0667 Bidirectional timestamps, e.g. NTP or PTP for compensation of clock drift and for compensation of propagation delays arrangements for monitoring round trip delays in packet switching networks H04L43/0864
• CPC Class Codes: H04W 52/0216 using a pre-established activity schedule, e.g. traffic indication frame
• CPC Class Codes: H04W 52/029 reducing the clock frequency of the controller
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

Aspects of a method and system for energy efficiency synchronization packet based networks are provided. In this regard, an amount that a clock of a network device drifts between consecutive communications of one or more synchronization packets may be determined, and transitions of the network device into and/or out-of an energy-saving mode of operation may be controlled based on the determination. Additionally or alternatively, the transitions may be controlled based on a number of times that synchronization packets are communicated between the network device and a link partner. An average difference between the clock of the network device and a reference clock may be calculated, and the transitions may be controlled based on the calculated average.

Claims

1. A method for communication, the method comprising:

performing by one or more circuits and/or processors in a network device;

determining an amount that a clock of said network device drifts between communications of one or more synchronization packets, wherein said synchronization packets are communicated between said network device and a link partner to which said network device is communicatively coupled; and

controlling transitions of said network device into and/or out-of an energy-saving mode of operation based on said determined amount.

2. The method according to claim 1, comprising:

controlling said transitions based on a number of times that said one or more synchronization packets are communicated between said network device and said link partner.

3. The method according to claim 1, comprising:

calculating a maximum number of consecutive ones of said communications of said one or more synchronization packets that said network device may skip before a difference between said clock of said network device and a reference clock is above a threshold; and

controlling said transitions based on said calculated maximum number.

4. The method according to claim 3, comprising controlling said transitions such that said network device does not continuously operate in said energy-saving mode for more than approximately N*T seconds, where N corresponds to said calculated maximum number, and T corresponds to an amount of time between consecutive ones of said communications of said one or more synchronization packets.

5. The method according to claim 1, comprising:

calculating a minimum number of consecutive ones of said communications of said one or more synchronization packets that said network device participates in to ensure that a difference between said clock of said network device and a reference clock is below a threshold; and

controlling said transitions based on said calculated minimum number.

6. The method according to claim 5, comprising controlling said transitions such that said network device does not transition into said energy-saving mode sooner than approximately M*T seconds after transitioning out of said energy-saving mode, where M corresponds to said calculated minimum number, and T corresponds to an amount of time between consecutive ones of said communications.

7. The method according to claim 1, comprising:

calculating an average difference between said clock of said network device and a reference clock; and

controlling said transitions based on said calculated average.

8. The method according to claim 1, wherein, while operating in said energy-saving mode, said network device operates in one or both of a low power idle mode and a sub-rating mode.

9. The method according to claim 1, wherein said communications of one or more synchronization packets comprises one or both of:

communicating packets comprising timestamps; and

communicating packets comprising a bit pattern from which a clock may be recovered.

10. The method according to claim 1, comprising, upon transitioning out of said energy-saving state and until said clock is resynchronized, generating an indication that said clock may have drifted by more than a particular amount.

19. The system according to claim 1, wherein said communications of one or more synchronization packets comprises one or both of:

communicating packets comprising timestamps; and

communicating packets comprising a bit pattern from which a clock may be recovered.

20. The system according to claim 1, wherein said one or more circuits and/or processors are operable to, upon transitioning out of said energy-saving state and until said clock is resynchronized, generate an indication that said clock may have drifted by more than a particular amount.

11. A system for networking, the system comprising:

one or more circuits and/or processors for use in a network device, wherein said one or more circuits and/or processors are operable to;

determine an amount that a clock of said network device drifts between communications of one or more synchronization packets, wherein said synchronization packets are communicated between said network device and a link partner to which said network device is communicatively coupled; and

control transitions of said network device into and/or out-of an energy-saving mode of operation based on said determined amount.

12. The system according to claim 11, wherein said one or more circuits and/or processors are operable to control said transitions based on a number of times that said one or more synchronization packets are communicated between said network device and said link partner.

13. The system according to claim 11, wherein said one or more circuits and/or processors are operable to:

calculate a maximum number of consecutive ones of said communications of said one or more synchronization packets that said network device may skip before a difference between said clock of said network device and a reference clock is above a threshold; and

control said transitions based on said calculated maximum number.

14. The system according to claim 13, wherein said one or more circuits and/or processors are operable to control said transitions such that said network device does not continuously operate in said energy-saving mode for more than approximately N*T seconds, where N corresponds to said calculated maximum number, and T corresponds to an amount of time between consecutive ones of said communications of said one or more synchronization packets.

15. The system according to claim 11, wherein said one or more circuits and/or processors are operable to:

calculate a minimum number of consecutive ones of said communications of said one or more synchronization packets that said network device participates in to ensure that a difference between a clock of said network device and a reference clock is below a threshold; and

control said transitions based on said calculated minimum number.

16. The system according to claim 15, wherein said one or more circuits and/or processors are operable to control said transitions such that said network device does not transition into said energy-saving mode sooner than approximately M*T seconds after transitioning out of said energy-saving mode, where M corresponds to said calculated minimum number, and T corresponds to an amount of time between consecutive ones of said communications.

17. The system according to claim 11, wherein said one or more circuits and/or processors are operable to calculate an average difference between said clock of said network device and a reference clock;

and

controlling said transitions based on said calculated average.

18. The system according to claim 11, wherein, while operating in said energy-saving mode, said network device operates in one or both of a low power idle mode and a sub-rating mode.