Method and system for supporting a variable and energy efficient data rate using a duty cycling technique and multiple power states on an Ethernet link

A method for data communications in a network between a first network node and a second network node over a network link, the first network node having a first host, a first media access control (MAC) and a first physical layer (PHY), the method comprising:

• cycling a transmit data rate at which said first PHY transmits first host data over said network link between a first non-zero data rate and at least a second non-zero data rate, wherein said first host data are obtained from said first host and processed by said first MAC and then said first PHY prior to said first PHY transmitting said first host data over said network link to said second network node;
• and
• cycling a receive data rate at which said first PHY receives second host data over said network link between said first non-zero data rate and said at least a second non-zero data rate being different than said first non-zero data rate, wherein said second host data are processed by said first PHY after being received by said first PHY and then by said first MAC prior to being provided to said first host;
• wherein a duty cycle of said transmit data is determined based on one or both of:
• a type of said first host data communicated over said network link and a type of said first host data to be communicated over said network link;
• and
• wherein said transmit data rate and said receive data rate are controlled by varying a number of physical channels of said network link via which data are communicated.