Section: 8.12.3 Mobile IAB-node integration
Content: During the integration, the mobile IAB-MT and the mobile IAB-DU can connect to the same IAB-donor or to different IAB-donors. The procedure for the latter case is shown in Figure 8.12.3-1. Figure 8.12.3-1: Decoupled mobile IAB-node integration procedure Phase 1: Equivalent procedure to Phase 1 of the IAB-node integration in SA mode in clause 8.12.1, where the mobile IAB-node and the RRC-terminating IAB-donor correspond to IAB-node 2 and the IAB-donor, respectively. The mobile IAB-node selects the parent node based on a mobile-IAB-specific over-the-air indication (transmitted in SIB1). The mobile IAB-MT includes a mobile-IAB-node-specific indication in the RRCSetupComplete message to assist the RRC-terminating IAB-donor in selecting an AMF supporting mobile IAB. Phase 2-1: Same as Phase 2-1 of procedure in clause 8.12.1. Phase 2-2: Same as Phase 2-2 of procedure in clause 8.12.1. Phase 3: Mobile IAB-DU part setup. In this phase, the mobile IAB-DU is configured via OAM. The configured information includes, e.g., the information of the F1-terminating IAB-donor-CU, to enable the mobile IAB-DU to initiate the establishment of F1-C to the F1-terminating IAB-donor-CU. The mobile IAB-DU initiates the TNL establishment, and F1 setup (as defined in clause 8.5) with the F1-terminating IAB-donor-CU using the default BAP routing ID and default BH RLC channel configured by the RRC-terminating IAB-donor-CU in Phase 2-1 for upstream traffic. During the F1 setup, the mobile IAB-DU includes the gNB ID of the RRC-terminating IAB-donor-CU and the BAP address of the co-located mobile IAB-MT in the F1 SETUP REQUEST message. The mobile IAB-node determines this gNB ID based on the over-the-air broadcast (SIB1) by the RRC-terminating IAB-donor. After the F1 is set up, the mobile IAB-node can start serving UEs. The F1-terminating IAB-donor-CU can initiate the IAB Transport Migration Management procedure towards the RRC-terminating IAB-donor-CU as defined in clause 8.17.3.1.