Determination of SSB/RMSI periodicity for IAB node
An IAB node performs a method for determining a periodicity of a SSB and/or a RMSI for use in an IAB backhaul link. The method may comprise one or more of: using a predetermined periodicity value; determining a periodicity value based on at least one different parameter; receiving a signaling message indicating a periodicity value and using the indicated periodicity value for the IAB backhaul link; and selecting a periodicity value from a plurality of permitted periodicity values.
1. A method performed at an integrated access and backhaul (IAB) node, comprising:
when performing initial cell search, assuming a predetermined synchronization signal block (SSB) transmission periodicity;
searching for an SSB of a cell at the predetermined SSB transmission periodicity;
acquiring system information from the searched SSB; and
setting up a connection to a first parent IAB node in the searched cell according to the acquired system information.
2. The method of claim 1 , wherein the first parent IAB is donor IAB of the searched cell.
3. The method of claim 1 , wherein the method is performed by Mobile-Termination, MT, function of the IAB node.
4. The method of claim 1 , wherein acquiring system information from the searched SSB comprising:
obtaining actual SSB transmission periodicity from the acquired system information.
5. The method of claim 4 , wherein the obtained actual SSB transmission periodicity are for SSBs for specific use in an IAB backhaul link.
6. The method of claim 4 , wherein the obtained actual SSB transmission periodicity is for SSBs that are reused for access UEs.
7. The method of claim 4 , when an IAB backhaul link between the IAB node and the first parent IAB node get failure, further comprising:
searching for an SSB at the obtained actual periodicity of SSBs; and
setting up a connection to a second parent IAB node, wherein the second parent IAB node differs from the first parent IAB node.
8. The method of claim 1 , wherein the searching an SSB at the predetermined SSB transmission periodicity comprises, searching a set of SSBs at the predetermined SSB transmission periodicity regardless of periodicity information on SSBs indicated in a broadcast signal.
9. The method of claim 1 , wherein the IAB node is under a non-standalone (NSA) deployment.
10. An integrated access and backhaul (IAB) node, comprising:
processing circuitry configured to execute program code stored in the memory, cause the IAB node to:
when performs initial cell search, assume a predetermined synchronization signal block (SSB) transmission periodicity;
search for an SSB of a cell at the predetermined SSB transmission periodicity;
acquire system information from the searched SSB; and
set up a connection to a first parent IAB node in the searched cell according to the acquired system information.
11. The IAB node according to claim 10 , wherein the first parent IAB is donor IAB of the searched cell.
12. The IAB node according to claim 10 , wherein the processing circuitry in Mobile-Termination, MT, function of the IAB node.
13. The IAB node according to claim 10 , wherein the memory includes instructions with, when executed by the processing circuitry, cause the IAB node to:
obtain actual SSB transmission periodicity from the acquired system information.
14. The IAB node according to claim 13 , wherein the memory further includes instructions with, when executed by the processing circuitry, cause the IAB node to:
when an IAB backhaul link between the IAB node and the first parent IAB node get failure, search for an SSB at the obtained actual periodicity of SSBs; and
set up a connection to a second parent IAB node, wherein the second parent IAB node differs from the first parent IAB node.
15. The IAB node according to claim 14 , wherein the IAB node is under an NSA deployment.
16. The IAB node according to claim 13 , wherein the obtained actual SSB transmission periodicity are SSBs that are for specific use in an IAB backhaul link.
17. The IAB node according to claim 13 , wherein the obtained actual SSB transmission periodicity is for SSBs that are reused for access UEs.
18. The IAB node according to claim 10 , wherein the IAB node is a terminal device.