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:
during the IAB node initial access to a first parent IAB node, wherein the IAB node firstly join an IAB backhaul link, assuming a predetermined synchronization signal block (SSB) transmission periodicity;
searching an SSB at the predetermined SSB transmission periodicity; and
getting access to the first parent IAB node according to the searched SSB.
2. The method of claim 1 , further comprising:
receiving system information from the first parent IAB node, according to the searched SSB; and
obtaining actual SSB transmission periodicity from the received system information.
3. The method of claim 2 , 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.
4. The method of claim 3 , wherein the SSBs indicated by the obtained actual SSB transmission periodicity are for specific use in an IAB backhaul link.
5. The method of claim 3 , wherein the SSBs indicated by the obtained actual SSB transmission periodicity are reusing a same set of SSBs used for access UEs.
6. The method of claim 2 , when the IAB backhaul link between the IAB node and the first parent IAB node get failure, further comprising:
searching an SSB at the obtained actual periodicity of SSBs; and
getting initial access to a second parent IAB node, wherein the second parent IAB node differs from the first parent IAB node.
7. The method of claim 1 , wherein the IAB node is under a non-standalone (NSA) deployment.
8. A method performed at an integrated access and backhaul (IAB) node, comprising:
during the IAB node initial access to a parent IAB node, determining its availability of synchronization signal block (SSB) transmission periodicity;
upon determining there is no information on actual SSB transmission periodicity in the IAB node, assuming a default SSB transmission periodicity;
searching an SSB at the default SSB transmission periodicity.
9. The method of claim 8 , further comprising:
upon determining an actual SSB transmission periodicity is available in the IAB node, searching an SSB at the actual SSB transmission periodicity.
10. The method of claim 9 , wherein SSBs indicated by the actual SSB transmission periodicity are for specific use in an IAB backhaul link.
11. The method of claim 9 , wherein SSBs indicated by the actual SSB transmission periodicity are reusing a same set of SSBs used for access UEs.
12. The method of claim 8 , wherein the determining its availability of SSB transmission periodicity by the IAB node is a feedback to a failure of IAB backhaul link between the IAB node and its parent IAB node.
13. The method of claim 8 , wherein the IAB node is under a non-standalone (NSA) deployment.
14. An integrated access and backhaul (IAB) node, comprising:
processing circuitry configured to execute program code stored in the memory, cause the IAB node to:
during the IAB node initial access to a first parent IAB node, wherein the IAB node firstly join an IAB backhaul link, assume a predetermined synchronization signal block (SSB) transmission periodicity;
search an SSB at the predetermined SSB transmission periodicity; and
get access to the first parent IAB node according to the searched SSB.
15. The IAB node according to claim 14 , wherein the memory further includes instructions with, when executed by the processing circuitry, cause the IAB node to:
receive system information from the first parent IAB node, according to the searched SSB; and
obtain actual SSB transmission periodicity from the received system information.
16. The IAB node according to claim 15 , wherein the memory further includes instructions with, when executed by the processing circuitry, cause the IAB node to:
when the IAB backhaul link between the IAB node and the first parent IAB node get failure, search an SSB at the obtained actual periodicity of SSBs; and
get initial access to a second parent IAB node, wherein the second parent IAB node differs from the first parent IAB node.
17. The IAB node according to claim 15 , wherein the SSBs indicated by the obtained actual SSB transmission periodicity are for specific use in an IAB backhaul link.
18. The IAB node according to claim 15 , wherein the SSBs indicated by the obtained actual SSB transmission periodicity are reusing a same set of SSBs used for access UEs.
19. The IAB node according to claim 14 , wherein the IAB node is under an NSA deployment.