Backoff window adjustment method, and apparatus
Embodiments of the present disclosure provide a backoff window adjustment method, and an apparatus. In downlink transmission, a base station obtains a trigger condition for adjusting a length of a backoff window on a first channel, and adjusts the length of the backoff window of the base station on the first channel according to the obtained trigger condition for adjusting the length of the backoff window on the first channel. In uplink transmission, a user equipment (UE) obtains a trigger condition for adjusting a length of a backoff window on a first channel, and adjusts the length of the backoff window of the UE on the first channel according to the obtained trigger condition for adjusting the length of the backoff window on the first channel.
1. A method for contention window adjustment, the method comprising:
receiving, by a first device, multiple pieces of response information, wherein the response information is for data packet transmission on a channel, and each piece of response information of the multiple pieces of response information is acknowledgment (ACK) information or negative acknowledgment (NACK) information; and
adjusting, by the first device, a contention window on the channel according to a ratio of a quantity of pieces of NACK information or ACK information in the multiple pieces of response information to a total quantity of the multiple pieces of response information.
2. The method according to claim 1 , wherein the adjusting the contention window comprises:
in response to determining that the ratio of the quantity of pieces of NACK information in the multiple pieces of response information to the total quantity of the multiple pieces of response information is greater than a preset first threshold, increasing, by the first device, the contention window on the channel.
3. The method according to claim 2 , wherein the adjusting the contention window further comprises:
in response to determining that the ratio of the quantity of pieces of ACK information in the multiple pieces of response information to the total quantity of the multiple pieces of response information is greater than a preset second threshold, decreasing, by the first device, the contention window on the channel or keeping the contention window unchanged.
4. The method according to claim 3 , wherein the decreasing, by the first device, the contention window on the channel or keeping the contention window unchanged comprises:
setting, by the first device, a length of the contention window to an initial value.
5. The method according to claim 1 , wherein the adjusting the contention window comprises:
in response to determining that the ratio of the quantity of pieces of ACK information in the multiple pieces of response information to the total quantity of the multiple pieces of response information is greater than a preset third threshold, decreasing, by the first device, the contention window on the channel or keeping the contention window unchanged.
6. The method according to claim 5 , wherein the decreasing, by the first device, the contention window on the channel or keeping the contention window unchanged comprises:
setting, by the first device, a length of the contention window to an initial value.
7. The method according to claim 1 , wherein the receiving, by the first device, the multiple pieces of response information comprises:
receiving, by the first device, the multiple pieces of response information from multiple second devices.
8. The method according to claim 1 , wherein the receiving, by the first device, the multiple pieces of response information comprises:
receiving, by the first device, the multiple pieces of response information from a second device.
9. The method according to claim 8 , wherein:
the first device is a terminal device and the second device is a base station; or
the first device is a base station and the second device is a terminal device.
10. The method according to claim 1 , wherein the contention window is a contention window of a licensed-assisted access (LAA) system.
11. An apparatus, comprising:
a memory; and
at least one processor coupled with the memory, wherein the at least one processor is configured to execute instructions stored in the memory, to cause a first device to perform:
receiving multiple pieces of response information, wherein the response information is for data packet transmission on a channel, and each piece of response information of the multiple pieces of response information is acknowledgment (ACK) information or negative acknowledgment (NACK) information; and
adjusting a contention window on the channel according to a ratio of a quantity of pieces of NACK information or ACK information in the multiple pieces of response information to a total quantity of pieces of the multiple pieces of response information.
12. The apparatus according to claim 11 , wherein the adjusting the contention window comprises:
in response to determining that the ratio of the quantity of pieces of NACK information in the multiple pieces of response information to the total quantity of pieces of the multiple pieces of response information is greater than a preset first threshold, increasing the contention window on the channel.
13. The apparatus according to claim 12 , wherein the adjusting the contention window further comprises:
in response to determining that the ratio of the quantity of pieces of ACK information in the multiple pieces of response information to the total quantity of pieces of the multiple pieces of response information is greater than a preset second threshold, decreasing the contention window on the channel or keeping the contention window on the channel unchanged.
14. The apparatus according to claim 13 , wherein the decreasing the contention window on the channel or keeping the contention window on the channel unchanged comprises:
setting a length of the contention window to an initial value.
15. The apparatus according to claim 11 , wherein the adjusting the contention window comprises:
in response to determining that the ratio of the quantity of pieces of ACK information in the multiple pieces of response information to the total quantity of pieces of the multiple pieces of response information is greater than a preset third threshold, decreasing the contention window on the channel or keeping the contention window on the channel unchanged.
16. The apparatus according to claim 15 , wherein the decreasing the contention window on the channel or keeping the contention window on the channel unchanged comprises:
setting a length of the contention window to an initial value.
17. The apparatus according to claim 11 , wherein the receiving the multiple pieces of response information comprises:
receiving the multiple pieces of response information from multiple second devices communicated with the first device.
18. The apparatus according to claim 11 , wherein the receiving the multiple pieces of response information comprises:
receiving the multiple pieces of response information from a second device communicated with the first device.
19. The apparatus according to claim 11 , wherein the contention window is a contention window of a licensed-assisted access (LAA) system.
20. A second device, comprising:
a communications interface configured to:
receive multiple data packets on a channel from a first device communicated with the second device; and
in response to receiving the multiple data packets, send multiple pieces of response information to the first device, wherein each piece of response information of the multiple pieces of response information is acknowledgment (ACK) information or negative acknowledgment (NACK) information, and wherein a ratio of a quantity of pieces of NACK information or ACK information in the multiple pieces of response information to a total quantity of pieces of the multiple pieces of response information is for adjusting a contention window on the channel.
21. The method according to claim 1 , wherein the adjusting the contention window comprises:
in response to determining that the quantity of pieces of ACK information in the multiple pieces of response information is greater than a preset fourth threshold, decreasing, by the first device, the contention window on the channel.
22. The apparatus according to claim 11 , wherein the adjusting the contention window comprises:
in response to determining that the quantity of pieces of ACK information in the multiple pieces of response information is greater than a preset fourth threshold, decreasing the contention window on the channel.