Interaction method between arq and harq for systems with long roundtrip delay

A method of interacting between an automatic repeat request (ARQ) and hybrid automatic repeat request (HARQ) in a system with a long roundtrip delay, the method comprising:

• determining, by a first layer unit, whether a packet transmission of a packet succeeds or fails, using first feedback information received in response to the packet transmission;
• transferring, by a second layer unit, a packet from a transmission window to a waiting window, when the first layer unit determines that the packet transmission of the packet succeeds;
• transferring, by the second layer unit, the packet from the transmission window to a retransmission window to retransmit the packet, when the first layer unit determines that the packet transmission of the packet fails;
• and
• receiving, by the second layer unit, second feedback information including the packet, and determining a process of the packet based on the second feedback information.