Energy-efficient Ethernet transceiver that adjusts based on environmental conditions
A physical layer transceiver for a node in a wireline communication system includes receiver circuitry for receiving communications from a link partner on a first link path, transmitter circuitry for transmitting communications to the link partner on a second link path, and an energy-efficient Ethernet (EEE) controller for reducing power consumption on the first or second link path, when activity on that link path is reduced. In a low-power mode, there are periodic refresh intervals of a first duration, during which signals are received or transmitted, and, between the refresh intervals, quiet intervals of a second, longer, duration, during which transmission and reception of signals are avoided. The EEE controller detects a change in an environmental condition affecting that link path, and upon detection of that change, adjusts a parameter of the low-power mode on at least one of the first and second link paths.
1. A physical layer transceiver for a node in a wireline communication system, the physical layer transceiver comprising:
receiver circuitry configured to receive communications from a link partner on a first link path;
transmitter circuitry configured to transmit communications to the link partner on a second link path; and
an energy-efficient Ethernet controller configured to reduce power consumption on one of the first link path and the second link path, when activity on the one of the first link path and the second link path is reduced, by entering, on the one of the first link path and the second link path, a low-power mode characterized by:
(i) periodic refresh intervals of a first duration, during which signals are received or transmitted, and
(ii) between the refresh intervals, quiet intervals during which transmission and reception of signals are avoided, the quiet intervals being of a second duration longer than the first duration,
wherein the energy-efficient Ethernet controller is further configured to:
detect a change in an environmental condition affecting one of the first link path and the second link path by:
monitoring at least one of power at one or more locations on the one of the first link path and the second link path, and signal to noise ratio on the one of the first link path and the second link path, and
observing that the at least one of the monitored power at one or more of the one or more locations, and the monitored signal to noise ratio, have values predetermined to indicate changing environmental conditions; and
upon detection of the change in the environmental condition affecting the one of the first link path and the second link path, adjust a parameter of the low-power mode on at least one of the first link path and the second link path.
2. The physical layer transceiver of claim 1 , wherein the physical layer transceiver connects the first link path and the second link path to a common channel medium.
3. The physical layer transceiver of claim 1 , wherein the energy-efficient Ethernet controller is configured to:
transmit refresh signals during the refresh intervals; and
adjust parameters of the low-power mode on the one of the first link path and the second link path by changing rates of adaptation in signals transmitted during the refresh intervals.
4. The physical layer transceiver of claim 1 , wherein the energy-efficient Ethernet controller is configured to:
transmit refresh signals during the refresh intervals; and
adjust parameters of the low-power mode on the one of the first link path and the second link path by changing timing of (i) the refresh intervals and (ii) the quiet intervals.
5. The physical layer transceiver of claim 4 , wherein the energy-efficient Ethernet controller is configured to change one or both of ON times and OFF times of a signal transmitted during the refresh intervals.
6. The physical layer transceiver of claim 4 , wherein the energy-efficient Ethernet controller is configured to change at least one of the first duration and the second duration.
7. The physical layer transceiver of claim 6 , wherein the energy-efficient Ethernet controller is configured to transmit a signal during at least one of the refresh intervals including an instruction to a second energy-efficient Ethernet controller, in a second node of the wireline communication system, to change at least one of the first duration and the second duration.
8. The physical layer transceiver of claim 7 , wherein the energy-efficient Ethernet controller is configured to transmit the signal during at least one of the refresh intervals, to instruct the second energy-efficient Ethernet controller in the second node, by changing polarity of a waveform of one of the signals transmitted in the at least one of the refresh intervals.
9. A wireline communication system comprising:
a first node and a second node, each node having a respective physical layer transceiver, each respective physical layer transceiver in a respective one of the first node and the second node including:
respective receiver circuitry configured to receive communications from another one of the first node and the second node;
respective transmitter circuitry configured to transmit communications to the other one of the first node and the second node; and
sensors configured to detect a change in an environmental condition affecting a link path between the first node and the second node, by:
monitoring at least one of power at one or more locations on the one of the first link path and the second link path, and signal to noise ratio on the one of the first link path and the second link path, and
observing that the at least one of the monitored power at one or more of the one or more locations, and the monitored signal to noise ratio, have values predetermined to indicate changing environmental conditions; wherein:
the respective transmitter circuitry in a respective one of the first node and the second node is configured to, upon detection of the change in the environmental condition affecting the link path, adjust parameters of the link path.
10. The wireline communication system of claim 9 , wherein the respective transmitter circuitry in a respective one of the first node and the second node is configured to, upon detection of the change in the environmental condition affecting the link path, change timing of refresh intervals and quiet intervals of a low-power mode.
11. The wireline communication system of claim 10 , wherein the respective transmitter circuitry in a respective one of the first node and the second node is configured to, upon detection of the change in the environmental condition affecting the link path, change one or both of ON times and OFF times of a signal transmitted during the refresh intervals.
12. The wireline communication system of claim 10 , wherein the respective transmitter circuitry in a respective one of the first node and the second node is configured to, upon detection of the change in the environmental condition affecting the link path, signal the respective other one of the first node and the second node to change at least one of duration of the refresh intervals and duration of the quiet intervals.
13. The wireline communication system of claim 10 , wherein the respective transmitter circuitry in a respective one of the first node and the second node is configured to, upon detection of the change in the environmental condition affecting the link path, signal the respective other one of the first node and the second node by changing polarity of a waveform of a signal transmitted in the at least one of the refresh intervals.
14. A method for reducing power consumption on a link path between a physical layer transceiver of a node in a wireline communication system and a link partner in the wireline communication system, the method comprising:
detecting changes in an environmental condition affecting the link path by:
monitoring at least one of power at one or more locations on the one of the first link path and the second link path, and signal to noise ratio on the one of the first link path and the second link path, and
observing that the at least one of the monitored power at one or more of the one or more locations, and the monitored signal to noise ratio, have values predetermined to indicate changing environmental conditions; and
upon detecting the change in the environmental condition affecting the link path, adjusting parameters of a low-power mode on the link path.
15. The method of claim 14 , wherein the adjusting comprises changing rates of adaptation in signals transmitted during refresh intervals of the low-power mode.
16. The method of claim 14 , wherein the adjusting comprises changing timing of refresh intervals and quiet intervals.
17. The method of claim 16 , wherein the changing timing of the refresh intervals and the quiet intervals comprises changing one or both of ON times and OFF times of signals transmitted during the refresh intervals.
18. The method of claim 16 , wherein the changing timing of the refresh intervals and the quiet intervals comprises changing at least one of duration of the refresh intervals and duration of the quiet intervals.
19. The method of claim 18 , wherein changing the ratio comprises transmitting a signal during at least one of the refresh intervals to instruct a link partner to change the at least one of the duration of the refresh intervals and the duration of the quiet intervals.
20. The method of claim 19 , wherein transmitting the signal comprises changing polarity of a waveform of a signal transmitted in the at least one of the refresh intervals.