Downlink buffer status feedback method and apparatus

1. An apparatus for a first node, comprising at least one processor and a non-transitory memory storage coupled to the at least one processor and storing programming instructions for execution by the at least one processor, wherein the programming instructions instruct the at least one processor to perform operations comprising:

determining first information, wherein the first information indicates a downlink buffer status of a first bearer between the first node and a second node, and the first bearer is an ingress radio link control (RLC) channel, and the first information comprises a logical channel identifier (LCID) that identifies the ingress RLC channel; and

sending the first information to the second node, wherein

the first node is a relay node in a wireless relay communications system, and the second node is a parent node of the first node.

2. The apparatus according to claim 1 , wherein the first information comprises a downlink buffer size of the first bearer.

3. The apparatus according to claim 2 , wherein the downlink buffer size of the first bearer comprises one or more of the following: a remaining downlink buffer size, a downlink buffer occupancy ratio, a first expected downlink transmission rate, a congestion level, a downlink buffer size combination, or indication information indicating whether the downlink buffer size of the first bearer exceeds a preset buffer size; and wherein the downlink buffer size combination comprises a total downlink buffer size and a current downlink buffer size.

4. The apparatus according to claim 1 , wherein the operations further comprise:

receiving second information from the second node, wherein the second information requests the first information.

5. The apparatus according to claim 1 , wherein the first information is carried in media access control (MAC) layer signaling or adaptation layer signaling.

6. The apparatus according to claim 5 , wherein the MAC layer signaling or the adaptation layer signaling is transmitted from a mobile terminal (MT) in the first node to a distributed unit (DU) in the second node.

7. An apparatus for a second node, comprising at least one processor and a non-transitory memory storage coupled to the at least one processor and storing programming instructions for execution by the at least one processor, wherein the programming instructions instruct the at least one processor to perform operations comprising:

receiving first information from a first node, wherein the first information indicates a downlink buffer status of a first bearer between the first node and the second node, and the first bearer is an ingress radio link control (RLC) channel, and the first information comprises a logical channel identifier (LCID) that identifies the ingress RLC channel; and wherein

the first node is a relay node in a wireless relay communications system, and the second node is a parent node of the first node.

8. The apparatus according to claim 7 , wherein the first information comprises a downlink buffer size of the first bearer.

9. The apparatus according to claim 8 , wherein the downlink buffer size of the first bearer comprises one or more of the following: a remaining downlink buffer size, a downlink buffer occupancy ratio, a first expected downlink transmission rate, a congestion level, a downlink buffer size combination, or indication information indicating whether the downlink buffer size of the first bearer exceeds a preset buffer size; and wherein the downlink buffer size combination comprises a total downlink buffer size and a current downlink buffer size.

10. The apparatus according to claim 7 , wherein the operations further comprise:

sending second information to the first node, wherein the second information requests the first information.

11. The apparatus according to claim 7 , wherein the operations further comprise:

controlling, by the second node and based on the first information, a transmission rate of downlink data transmitted to the first node.

12. The apparatus according to claim 7 , wherein the first information is carried in media access control (MAC) layer signaling or adaptation layer signaling.

13. The apparatus according to claim 12 , wherein the MAC layer signaling or the adaptation layer signaling is transmitted from a mobile terminal (MT) in the first node to a distributed unit (DU) in the second node.

14. A downlink buffer status feedback method, wherein the method comprises:

determining, by a first node, first information, wherein the first information indicates a downlink buffer status of a first bearer between the first node and a second node, and the first bearer is an ingress radio link control (RLC) channel, and the first information comprises a logical channel identifier (LCID) that identifies the ingress RLC channel; and

sending, by the first node, the first information to the second node, wherein

the first node is a relay node in a wireless relay communications system, and the second node is a parent node of the first node.

15. The method according to claim 14 , wherein the first information comprises a downlink buffer size of the first bearer.

16. The method according to claim 15 , wherein the downlink buffer size of the first bearer comprises one or more of the following: a remaining downlink buffer size, a downlink buffer occupancy ratio, a first expected downlink transmission rate, a congestion level, a downlink buffer size combination, or indication information indicating whether the downlink buffer size of the first bearer exceeds a preset buffer size; and wherein the downlink buffer size combination comprises a total downlink buffer size and a current downlink buffer size.

17. The method according to claim 14 , wherein the method further comprises:

receiving, by the first node, second information from the second node, wherein the second information requests the first information.