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.