IAB-DONOR DEVICE AND TRANSPORT MIGRATION MANAGEMENT METHOD

1 . An integrated access and backhaul (IAB) donor device in a first donor-CU, the device comprising:

a transmitter configured to transmit an IAB transport migration management request for a migrated traffic to a second donor-CU, and

wherein the IAB transport migration management request is used to request for releasing a resource serving for the traffic in the topology of the second donor-CU, wherein an IAB-DU of an IAB node maintains F1 connection with the first donor-CU, and the resource serving for the traffic of the IAB node has been established in a topology of the second donor-CU.

2 . The device according to claim 1 , wherein an IAB-MT of the IAB-node maintains radio resource control connection with the second donor-CU, or the IAB-MT of the IAB-node maintains radio resource control connection with the first donor-CU.

3 . The device according to claim 1 , wherein the traffic includes at least one or a combination of the following: an F1 control plane traffic, an F1 user plane traffic, or a non-F1 traffic.

4 . The device according to claim 1 , wherein in a case where the traffic is migrated from the topology of the second donor-CU back to a topology of the first donor-CU, or when the traffic ends, the transmitter transmits the IAB transport migration management request to the second donor-CU.

5 . The device according to claim 1 , the device further comprising:

processor circuitry configured to perform at least one of the following operations:

configuring the IAB-node with updated uplink BH information for the traffic;

configuring the IAB-node to release at least one of the following: header rewriting information of a backhaul adaptation protocol between the topology of the first donor-CU and the topology of the second donor-CU, routing information in the topology of the second donor-CU, or backhaul radio link control channel mapping information between the topology of the first donor-CU and the topology of the second donor-CU;

configuring the IAB-node to increase routing information in the topology of the first donor-CU and/or backhaul radio link control channel mapping information in the topology of the first donor-CU;

configuring the IAB-node with an IP address anchored at a donor-DU of the first donor-CU; or

configuring backhaul adaptation protocol sublayer routing and/or a backhaul radio link control channel used by the traffic on a path in the topology of the first donor-CU.

6 . The device according to claim 1 , wherein the IAB transport migration management request includes a traffic identifier needing to be released.

7 . The device according to claim 1 , wherein in a case where the IAB-MT of the IAB-node is handed over from the first donor-CU to the second donor-CU, and one or more resources serving for one or more traffics of the IAB-node has/have been established in the topology of the second donor-CU, the transmitter transmits the IAB transport migration management request for the one or more traffics;

or, in a case where the IAB-MT of the IAB-node performs reestablishment from the first donor-CU to the second donor-CU, and one or more resources serving for one or more traffics of the IAB-node has/have been established in the topology of the second donor-CU, the transmitter transmits the IAB transport migration management request for the one or more traffics;

or, in a case where the IAB-MT of the IAB-node has established dual-connection with the first donor-CU and the second donor-CU, and one or more resources serving for one or more traffics of the IAB-node has/have been established in the topology of the second donor-CU, the transmitter transmits the IAB transport migration management request for the one or more traffics.

8 . An integrated access and backhaul (IAB) donor device in a second donor-CU, the device comprising:

a transmitter configured to transmit an IAB transport migration modification request for a migrated traffic to a first donor-CU; and

processor circuitry configured to release a resource serving for the traffic in a topology of the second donor-CU, and

wherein an IAB-DU of an IAB node maintains F1 connection with the first donor-CU, and the resource serving for the traffic of the IAB node has been established in the topology of the second donor-CU.

9 . The device according to claim 8 , wherein in a case of revoking the migrated traffic from the topology of the second donor-CU back to the topology of the first donor-CU, the transmitter transmits the IAB transport migration modification request for the traffic to the first donor-CU.

10 . The device according to claim 8 , wherein the IAB transport migration modification request includes a traffic identifier needing to be released.

11 . The device according to claim 8 , the device further comprising:

a receiver configured to receive an IAB transport migration modification response transmitted by the first donor-CU.

12 . The device according to claim 11 , wherein the IAB transport migration modification response includes an identifier of a traffic that is successfully released.

13 . The device according to claim 11 , wherein after receiving the IAB transport migration modification response, the processor circuitry releases backhaul adaptation protocol sublayer routing and/or a backhaul radio link control channel used by the traffic on a path in the topology of the second donor-CU.

14 . The device according to claim 11 , wherein the receiver further receives an IAB transport migration modification response transmitted by the first donor-CU for rejecting the IAB transport migration modification request for the traffic.

15 . The device according to claim 14 , wherein the IAB transport migration modification response is received via a transport migration management response message.

16 . The device according to claim 14 , wherein the IAB transport migration modification response includes an identifier of the traffic.

17 . The device according to claim 8 , wherein in a case where the IAB-MT of the IAB-node is handed over from the first donor-CU to the second donor-CU, and one or more resources serving for one or more traffics of the IAB-node has/have been established in the topology of the second donor-CU, the transmitter transmits the IAB transport migration modification request for the one or more traffics;

or, in a case where the IAB-MT of the IAB-node performs reestablishment from the first donor-CU to the second donor-CU, and one or more resources serving for one or more traffics of the IAB-node has/have been established in the topology of the second donor-CU, the transmitter transmits the IAB transport migration modification request for the one or more traffics;

or, in a case where the IAB-MT of the IAB-node has established dual-connection with the first donor-CU and the second donor-CU, and one or more resources serving for one or more traffics of the IAB-node has/have been established in the topology of the second donor-CU, the transmitter transmits the IAB transport migration modification request for the one or more traffics.

18 . An integrated access and backhaul (IAB) system, comprising a first donor-CU and a second donor-CU;

the first donor-CU transmits an IAB transport migration management request for a traffic, wherein the IAB transport migration management request is used to request for releasing a resource serving for the traffic in a topology of the second donor-CU; the second donor-CU receives the IAB transport migration management request;

or,

the second donor-CU transmits an IAB transport migration modification request for the traffic, and releases the resource serving for the traffic in the topology of the second donor-CU; the first donor-CU receives the LAB transport migration modification request.