Patent ID: 8276011

Claim:
An energy efficient Ethernet method in a physical layer device, comprising: determining, by an energy efficiency control policy contained in the physical layer device, a need to transition between energy saving states, said determination being based on an analysis by said energy efficiency control policy of link utilization indicated by traffic-based measurements, said determination being independent of an energy saving state change command that is directed to the physical layer device from a higher layer; generating, in response to said determination of said need to transition between energy saving states, a first physical coding sublayer code group having a value that indicates a sequence ordered set and one or more additional physical coding sublayer code groups that indicate a transition of the physical layer device to a new energy saving state; and transmitting information including said first physical coding sublayer code group and said one or more additional physical coding sublayer code groups to a media access control layer, said transmitted information alerting said media access control layer that the physical layer device has transitioned to said new energy saving state.