Operation of automatic repeat request
There is disclosed a node for a wireless communication system. The node may comprise a receiver for receiving a data packet, a status report and an acknowledgement (ACK), a transmitter for transmitting the packet, the status reports and the ACK and a processor for selectively operating in a first mode and a second mode, for determining a mode switching criterion.
1. A method performed by a node relaying a communication between a user equipment (UE) and an integrated access and backhaul (IAB) donor in a wireless communication system, the method comprising:
performing an automatic repeat request (ARQ) based on a current mode, wherein the current mode is one among a first mode associated with end-to-end ARQ and a second mode associated with hop-by-hop ARQ;
switching the current mode to the other one among the first mode and the second mode based on one or more criteria for switching between modes; and
performing the ARQ based on the switched current mode,
wherein the switching of the current mode comprises:
in case that the current mode is the first mode and a transmission delay is greater than a first threshold, switching the current mode to the second mode.
2. The method of claim 1 , wherein, in case that the current mode is the second mode, a packet is buffered in the node until an acknowledgement (ACK) corresponding to the packet is received from the UE.
3. The method of claim 2 , wherein the performing of the ARQ based on the current mode comprises:
receiving a status report including a field associated with retransmission of the packet.
4. The method of claim 3 , wherein the performing of the ARQ based on the current mode further comprises:
updating the field included in the status report based on the ACK.
5. The method of claim 1 , wherein the one or more criteria comprise:
information associated with a link failure.
6. The method of claim 1 , wherein the ARQ is associated with downlink transmission.
7. The method of claim 1 , wherein the switching of the current mode further comprises:
in case that the current mode is the second mode and a likelihood that a transmission window of the IAB donor stalls is greater than a second threshold, switching the current mode to the first mode.
8. A node relaying a communication between a user equipment (UE) and an integrated access and backhaul (IAB) donor in a wireless communication system, the node comprising:
a transceiver; and
at least one processor configured to:
perform an automatic repeat request (ARQ) based on a current mode, wherein the current mode is one among a first mode associated with end-to-end ARQ and a second mode associated with hop-by-hop ARQ;
switch the current mode to the other one among the first mode and the second mode based on one or more criteria for switching between modes; and
perform the ARQ based on the switched current mode,
wherein the at least one processor is further configured to:
in case that the current mode is the first mode and a transmission delay is greater than a first threshold, switch the current mode to the second mode.
9. The node of claim 8 , wherein, in case that the current mode is the second mode, a packet is buffered in the node until an acknowledgement (ACK) corresponding to the packet is received from the UE.
10. The node of claim 9 , wherein the at least one processor is further configured to:
receive via the transceiver, a status report including a field associated with retransmission of the packet.
11. The node of claim 10 ,
wherein the at least one processor is further configured to:
update the field included in the status report based on the ACK.
12. The node of claim 8 , wherein the one or more criteria comprise:
information associated with a link failure.
13. The node of claim 8 , wherein the ARQ is associated with downlink transmission.
14. The node of claim 8 , wherein the at least one processor is further configured to:
in case that the current mode is the second mode and a likelihood that a transmission window of the IAB donor stalls is greater than a second threshold, switch the current mode to the first mode.