COMMUNICATION METHOD FOR NETWORK NODE, COMMUNICATION METHOD FOR MOBILE NODE, MOBILE NODE, AND DONOR DEVICE

1 . A donor device, applicable to an F1-terminating donor-CU of a mobile IAB node, the donor device comprising:

a receiver configured to receive first indication information, the first indication information comprising identity information related to a third donor-CU which is an RRC-terminating donor-CU after migration or radio link failure recovery of the mobile IAB node; and

a transmitter configured to transmit second indication information for indicating a context of a traffic to the third donor-CU.

2 . The donor device according to claim 1 , wherein the receiver is further configured to receive the first indication information when the mobile IAB node is migrated from a second donor-CU to the third donor-CU, the second donor-CU being an RRC-terminating donor-CU before migration or radio link failure recovery of the mobile IAB node.

3 . The donor device according to claim 1 , wherein the receiver further receives address information of the mobile IAB node anchored at the third donor-CU and transmitted by the mobile IAB node.

4 . The donor device according to claim 1 , wherein the second indication information is transmitted via an IAB transport migration management request message, and the second indication information comprises downlink address information so that the third donor-CU configures or modifies downlink mapping;

and the receiver further receives an IAB transport migration management response message transmitted by the third donor-CU, the IAB transport migration management response message comprising mapping information of a traffic to be offloaded and/or layer 2 information in a topology of the third donor-CU.

5 . The donor device according to claim 1 , wherein the transmitter further transmits to the mobile IAB node updated uplink backhaul information of the traffic based on the uplink backhaul information received from the third donor-CU.

6 . The donor device according to claim 2 , wherein,

the second donor-CU transmits an Xn HANDOVER REQUEST message to the third donor-CU, the message comprising the mobile IAB-node's TNL address information in an RRC container.

7 . The donor device according to claim 1 , wherein the first indication information is transmitted by the mobile IAB node via an F1AP message, the F1AP message being a gNB-DU configuration update message.

8 . The donor device according to claim 7 , wherein the F1AP message further comprises the mobile IAB node's address information anchored at the third donor-CU.

9 . The donor device according to claim 7 , wherein the first indication information is a global gNB ID of a target IAB donor.

10 . The donor device according to claim 1 , wherein,

the transmitter further transmits an IAB transport migration management request message to the third donor-CU for releasing all or a part of offloaded traffics.

11 . A mobile IAB node, comprising:

a transmitter configured to transmit first indication information to a first donor-CU which is an F1-terminating donor-CU of the mobile IAB node, the first indication information comprising identity information related to a third donor-CU which is an RRC-terminating donor-CU after migration or radio link failure recovery of the mobile IAB node.

12 . The mobile IAB node according to claim 11 , wherein the first indication information is used for the first donor-CU to transmit second indication information for indicating a context of a traffic to the third donor-CU.

13 . The mobile IAB node according to claim 11 , wherein the transmitter is configured to further transmit the address information anchored at the third donor-CU to the first donor-CU.

14 . The mobile IAB node according to claim 11 , wherein,

F1-C connection between the mobile IAB node and the first donor-CU is switched to a target path using new TNL address information of the mobile IAB node.

15 . The mobile IAB node according to claim 14 , wherein the mobile IAB node further reports new TNL address it wants to use for F1-U traffic to the first donor-CU, via gNB-DU CONFIGURATION UPDATE message.

16 . The mobile IAB node according to claim 15 , wherein the F1-U connections between the mobile IAB node and the first donor-CU are switched using the new TNL address.

17 . A donor device, applicable to an RRC-terminating donor-CU after migration or radio link failure recovery of a mobile IAB node,

the donor device comprising:

a receiver configured to receive second indication information used for indicating a context of a traffic and transmitted by a first donor-CU according to identity information,

wherein the first donor-CU is an F1-terminating donor-CU of the mobile IAB node, and the identity information is related to the donor device and is contained in the first indication information received by the first donor-CU.

18 . The donor device according to claim 17 , wherein the second indication information is transmitted via an IAB transport migration management request message, and

the donor device further comprising:

processor circuitry configured to configure or modify downlink mapping according to downlink address information included in the second indication information.

19 . The donor device according to claim 18 , the donor device further comprising:

a transmitter configured to transmit an IAB transport migration management response message to the first donor-CU, the IAB transport migration management response message comprising mapping information of a traffic to be offloaded and/or layer 2 information in a topology of the donor device.

20 . The donor device according to claim 18 , wherein the donor device further reconfigures BH RLC channels and BAP sublayer routing entries on a target path from the mobile IAB node to the donor device.