Why UE need to read SIB during HO?

Hello Experts.
I have seen documents about SIB Read failure during HO.
Why UE need to read SIB?

By reading sib UE get to know about prach info that UE need to perform for HO to get camp on traget cell.

This is my understanding, please correct me if I’m wrong.

RRC connection reconfiguration message contains all SIB2 related information, and contention free RACH and C-rnti provided by target eNB inside same message.

But still some document states RLF scenario giving a cause as SIB read failure.

Anyone ever seen this cause?

Are you sure that SIB read failure is due to missing SIB2 or SIB1?

Not, not saying that.

What I have seen that SIB2 parameters were given to UE in RRC connection reconfiguration.

But as per some docs i read, there comes a scenario when RLF happens due to SIB read failure.

So question comes: why UE need to read SIB in HO execution phase?

I think its a case of RLF where UE will not able to read SIB of Target cell after handover.

While UE in connected mode why he need to read SIB?

To get plmn info…etc of the target cell?

After handover, UE is necesarily need to decode MIB/SIB of target cell withing predefined time.
If UE fails, it will have to perform RLF.
By looking at content of MIB and SIB1, will come to know why UE need to decode it.
RRC reconfiguration (HO command) will not have all the information of target cell like SFN, PHICH resources, PLMN, scehduling periodicity of ther SIBs in target cell etc.
Hence it is required to read target cell MIB/SIB.

Seems good, let me dig more on this. :+1:

I cross-checked this and figured out that PHICH resource is already provided inside RRC re-config, no info found for SFN.
UE reads SIB1 to get CGI / cell id / eCGI info since this is not sent by target enb. Thus UE has to get this info by reading SIB1 of target enb.