Technique of link state detection and wakeup in power state oblivious interface

A method of a first device for transmitting a message, comprising:

• transmitting a first message to a second device;
• receiving a second message;
• determining whether the second message is an echo of the first message;
• and
• retransmitting the first message to the second device when the second message is the echo of the first message.

A first device for transmitting a message, comprising:

• means for transmitting a first message to a second device;
• means for receiving a second message;
• means for determining whether the second message is an echo of the first message;
• and
• means for retransmitting the first message to the second device when the second message is the echo of the first message.

A receiving device for detecting a message during a sleep state, comprising:

• a memory;
• and
• a processing circuit coupled to the memory and configured to:
• enable a loopback switch when the receiving device enters a sleep state,
• detect a first message from a transmitting device during the sleep state,
• perform a wakeup operation based on the detected first message,
• transmit a second message to the transmitting device via the enabled loopback switch, wherein the second message is an echo of the first message, and
• receive a retransmission of the first message from the transmitting device after wakeup of the receiving device.