System and method for controlling a PHY attached to a MAC interface for energy efficient ethernet
View Patent ↗A system and method for controlling a physical layer device attached to a media access control interface for energy efficient Ethernet. Detecting of a condition that is conducive to a change in a link rate can be performed at either link partner. In one embodiment, a control message based on the detection can be sent to a physical layer device via a media access control layer interface to effect a link rate change in the physical layer device.
1. An energy efficient Ethernet method, comprising:
detecting a condition that is conducive to a change in a link rate of an Ethernet link;
sending a message to a media access control layer that identifies a change to a link rate of said Ethernet link;
changing a rate of operation of said media access control layer after receipt of said message;
signaling, by said media access control layer to a physical layer device, an instruction to change said link rate of said physical layer device; and
changing an operating state of said physical layer device upon receipt of said instruction.
2. The method of claim 1 , wherein said detecting comprises monitoring a buffer or queue.
3. The method of claim 1 , wherein said detecting comprises monitoring a subsystem state.
4. The method of claim 1 , wherein said signaling is done in band.
5. The method of claim 1 , wherein said signaling is done out of band.
6. The method of claim 1 , wherein said changing an operating state comprises switching to a subset physical layer device.
7. The method of claim 1 , wherein said changing an operating state comprises switching to a low power idle mode.
8. The method of claim 1 , wherein said changing an operating state comprises switching from a subset physical layer device to a parent physical layer device.
9. The method of claim 1 , wherein said changing an operating state comprises switching from a low power idle mode to an active mode.
10. The method of claim 1 , wherein said changing a rate of operation of said media access control layer comprises changing a rate of operation of an interface with said physical layer device.
11. An energy efficient Ethernet method in a physical layer device, comprising:
receiving a link utilization change message via an interface that couples the physical layer device to a media access control layer;
switching from a first link rate to a second link rate in response to a receipt of said link utilization change message, wherein one of said first link rate and said second link rate is lower than the other link rate; and
switching a part of said media access control layer that supports said interface from a first rate to a second rate in response to a condition that produces said link utilization change message.
12. The method of claim 11 , wherein said receiving comprises receiving via in band signaling on said interface.
13. The method of claim 11 , wherein said receiving comprises receiving via out of band signaling on said interface.
14. An energy efficient Ethernet method, comprising:
detecting, using components in a layer above a media access control layer, a condition that is conducive to a change in a link rate of an Ethernet link;
sending, in response to said detection, a message to said media access control layer that indicates a change a link rate of said Ethernet link;
signaling, by said media access control layer to a physical layer device, an instruction to change said link rate of said physical layer device;
changing, in response to said message, an operating state of a part of said media access control layer that supports an interface between said media access control layer and said physical layer device; and
changing an operating state of said physical layer device upon receipt of said instruction from said media access control layer.
15. The method of claim 14 , wherein said detecting comprises monitoring a subsystem status.
16. The method of claim 14 , wherein said detecting comprises monitoring in an application layer.
17. The method of claim 14 , wherein said detecting comprises monitoring a bandwidth allocation protocol.
18. The method of claim 14 , wherein said changing an operating state of said physical layer device comprises changing to a subset mode of operation.
19. The method of claim 14 , wherein said changing an operating state of said physical layer device comprises changing to a low power idle mode of operation.
20. The method of claim 14 , wherein said signaling comprises signaling using in band communication on said interface.
21. The method of claim 14 , wherein said signaling comprises signaling using out of band communication on said interface.