Hello everyone!
I was wondering if anyone here can help me with any information regarding the scheduling of Other SIBs, specifically other that SIB1. I got sib 1 to work and received it at UE, but I am unable to send and decode other SIBs (e.g. SIB2)
Hi,
For 5G NR, SIB1 will carry all the essential system information. Along with this it can carry details about other SIBs which can be either:
Periodically broadcasted or
SIB 1 will contain details related to On demand via system information request. If this is the case Other system information (OSI) can be requested Via RACH and network will respond with OSI/SIB2-SIB9 as a response.
Elaborating more on OSI request - SIB1 will contain SI-SchedulingInfo IE , which will guide UE on to select unique PRACH Preambles and resources assigned for OSI request.
a) UE will trigger CBRA RACH procedure, MSG1 and MSG2 are same as regular RACH.
b) In MSG3 UE will send SI-Request which is included in RRC System Info Request Message. There is an IE requested-SIList which allows UE to request all SIBs or specific SIBs.
c) As a response of MSG3 , network will send other requested system information.
You can refer to 3GPP TS 38.331 5.2.2.3.3. For a simpler understanding you can also refer to 5G NR in Bullet Section 06 (Pg.265) and find more details.
Hope this helps you with your query. Happy to discuss further and learn from further interactions.
Quick reference from 5G NR bullet book.
https://www.sharetechnote.com/html/TroubleshootTips.html
a) The frequency specified in the band indicator in SIB1 does not match with the band that UE detected.
b) The SIBs from the cell ID and PLMN (in SIB1) has already decoded. (If you configured the two cells with same cell ID and PLMN, definitely by mistake, the SIBs (except SIB1) for the second cell may not be decoded because UE think it has already decoded all the SIBs when it camp on the first cell.
