Network Clock Synchronization Floating Window and Window Delineation

• US 20100316069A1
• Filed: 08/24/2010
• Published: 12/16/2010
• Est. Priority Date: 09/25/2006
• Status: Active Grant

• Current Assignee: Futurewei Technologies Incorporated (Huawei Investment & Holding Co., Ltd.)
• Original Assignee: Futurewei Technologies Incorporated (Huawei Investment & Holding Co., Ltd.)
• Inventors: Fourcand, Serge Francois
• Granted Patent: US 9,019,996 B2
• Time in Patent Office: Days
• US Class Current: 370/503
• CPC Class Codes: H04J 3/0605 Special codes used as synchronising signal
• CPC Class Codes: H04J 3/0682 by delay compensation, e.g. by compensation of propagation delay or variations thereof, by ranging
• CPC Class Codes: H04L 12/66 Arrangements for connecting between networks having differing types of switching systems, e.g. gateways

Abstract

A network component comprising at least one processor configured to implement a method comprising initiating a synchronization window, and promoting the transmission of a frame comprising a control symbol, wherein the control symbol delineates a beginning of the frame, and wherein the control symbol is offset from the beginning of the synchronization window. Also disclosed is a system comprising an upstream node in communication with a downstream node, wherein the upstream node transmits a data stream comprising a plurality of frames to the downstream node, wherein the data stream is organized into a plurality of synchronization windows, and wherein the frames float within the synchronization windows. Included is a method comprising transmitting an Ethernet data stream comprising an Ethernet control symbol, wherein the Ethernet control symbol is transmitted within a synchronization window and delineates a start of a packet within the synchronization window.

Claims

1. A network component comprising:

at least one processor coupled to a memory and configured to implement a method comprising;

initiating a synchronization window; and

promoting the transmission of a frame comprising a control symbol,

wherein the control symbol delineates a beginning of the frame, and

wherein the beginning of the control symbol is not the same as the beginning of the synchronization window.

2. The component of claim 1 wherein the method further comprises:

promoting transmission of a plurality of the frames, wherein the location of the control symbol relative to the synchronization window is not the same in each of the frames.

3. The component of claim 1, wherein each synchronization window is comprised of a first interval and a second interval, and wherein the frame is transmitted during the second interval.

4. The component of claim 3, wherein the frame further comprises a header and a payload, and wherein the payload comprises a plurality of timeslots.

5. The component of claim 4, wherein the timeslots comprise Best Effort Packet (BEP) data and Time Division Multiplexed (TDM) data, High Performance Flow (HPF) data, or both.

6. The component of claim 5, wherein the header comprises a time slot (TS) map indicating a data type assigned to each timeslot.

7. The component of claim 5, wherein the header comprises a synchronization timestamp that allows a plurality of nodes to synchronize their synchronization windows.

8. The component of claim 5, wherein the header comprises a synchronous optical networks (SONET)/synchronous digital hierarchy (SDH) overhead.

9. The component of claim 8, wherein the SONET/SDH overhead enables the payload to be mapped between Ethernet networks and SONET/SDH networks.

10. The component of claim 3, wherein the control symbol delineates a beginning of the second interval.

11. The component of claim 10, wherein the method further comprises promoting the transmission of a low priority data, wherein at least a portion of the low priority data is transmitted during the first interval.

12. The component of claim 11, wherein at least a portion of the low priority data is transmitted during the second interval.

13. The component of claim 11, wherein the low priority data is Best Effort Packet (BEP) data.

14. The component of claim 11, wherein the synchronization window comprises a third interval, and wherein at least a portion of the low priority data is transmitted during the third interval.

15. The component of claim 14, wherein the integrity of the frame is maintained when at least some of the data in the first interval, the third interval, or both is lost.

16. The component of claim 1, wherein the synchronization window has a period of about 125 microseconds.

17. A method comprising:

transmitting, by a processor coupled to a memory, an Open Systems Interconnection (OSI) layer two data stream comprising an Ethernet control symbol,

wherein the Ethernet control symbol is transmitted within a synchronization window and delineates a start of a packet within the synchronization window, and

wherein the packet comprises a header and a payload.

18. The method of claim 17, wherein the Ethernet control symbol is a /K28.1/ control symbol.

19. The method of claim 17, wherein the Ethernet control symbol precedes a clock synchronization data, and wherein the header comprises the Ethernet control symbol and the clock synchronization data.

20. The method of claim 17, wherein the Ethernet control symbol interrupts an Ethernet best effort packet.