Tech-invite3GPPspaceIETF RFCsSIP

Content for  TS 38.401  Word version:  17.5.0

Top   Top   Up   Prev   Next
1…   5…   6…   6.1.4   6.1.5…   6.2…   7…   8…   8.2…   8.2.2…   8.2.3…   8.2.4   8.2.5   8.3…   8.4…   8.4.4…   8.5…   8.9…   8.9.4…   8.9.6…   8.9.7…   8.10   8.11…   8.12…   8.13…   8.14…   8.15…   8.15.2…   8.16…   8.17…   8.17.3…   8.17.4   8.18…   8.19…   8.19.2   8.19.3   8.19.4…   9…   A…


8.2.5  Intra-CU Backhaul RLF recovery for IAB-nodes in SA mode |R16|p. 43

The intra-CU backhaul RLF recovery procedure for IAB-nodes in SA mode enables migration of an IAB-node to another parent node underneath the same IAB-donor-CU, when the IAB-MT declares a backhaul RLF. The declaration of backhaul RLF is described in TS 38.331.
Figure 8.2.5-1 shows an example of the BH RLF recovery procedure for an IAB-node in SA mode. In this example, the IAB-node changes from its initial parent node to a new parent node, where the new parent node is served by an IAB-donor-DU different than the one serving its initial parent node.
Reproduction of 3GPP TS 38.401, Fig. 8.2.5-1: IAB intra-CU backhaul RLF recovery procedure for an IAB-node in SA mode
Step 1.
The IAB-MT declares BH RLF for the MCG as described in clause of TS 38.331.
Step 2.
The IAB-MT undergoing recovery from RLF conducts the RRC re-establishment procedure at the new parent node, as defined in clause 8.7. In this procedure, the IAB-donor-CU may provide new TNL address(es), which is(are) anchored at the new IAB-donor-DU, to the IAB-MT via RRC signalling. Furthermore, the IAB-donor-CU may also provide a new default UL mapping which includes a default BH RLC channel and a default BAP Routing ID for UL F1-C/non-F1 traffic on the target path, to the IAB-node undergoing recovery from RLF via RRCReconfiguration message in this procedure.
Step 3.
The remaining part of the procedure follows the steps 11-15 of the intra-CU topology adaptation procedure defined in clause
Descendant node(s) of the IAB-node undergoing recovery from RLF may also need to switch to new TNL address(es) anchored in the target-path IAB-donor-DU following the same mechanism as described for IAB intra-CU topology adaptation procedure in clause The descendant node(s) may also be provided with new default UL mapping via RRC, after the IAB-node undergoing recovery from RLF connects the IAB-donor-CU via the recovery path.

Up   Top   ToC