Hello Experts.
As we know, SIB1 contains common broadcast information that should be uniform for all device categories, whether RedCap or non-RedCap.
However, we observed an issue where, on the same cell, a RedCap device detected the common RedCap configuration in SIB1, while a regular non-RedCap device did not detect this configuration in the same SIB1.
How is it possible for common broadcast information to differ for different device categories on the same cell?
Hi,
The redCapConfigCommon is designed specifically for redCap UEs.
For non-redCap UEs, it is up to the UE implementation to decide whether to decode or simply ignore redCap-related IEs, as they do not belong to the redCap UE group.
The SIB1 broadcast by the cell will include all information. However, non-redCap UEs are expected to disregard the redCapConfigCommon section.
Are there other examples where an IE is ignored from a common broadcast message?
To address this, we would need IEs in SIB1 that were introduced in the latest version of 3GPP and are not supported by the UE.
As far as I know, there aren’t any such IEs currently.
Ultimately, it also depends on the chipset manufacturer whether the UE will decode or ignore them.
In SIB1, there is an IE called intraFrequencyReselectionR17 that is relevant for redCap cells.
This IE helps redCap UEs identify redCap capabilities. Non-redCap UEs simply ignore this IE; however, the SIB1 structure remains the same for all UEs, regardless of their type.
Exactly, it should be common to all UEs.
However, it is possible that a UE chipset could be designed in such a way that, if it does not support redCap in Release 17, it may ignore that part (redCap-ConfigCommon-r17).
It’s quite possible and depends on the UE’s ASN implementation.
