Does anyone let me know, for NSA mode, does we get 5G measurement ( ss-RSRP, ss-RSRQ etc) in RRC idle mode?
No, first 5G measurements are in connected mode when UE measures ss-rsrp to report event b1 to enodeB to trigger scg addition via rrc connection reconfiguration.
Thanks @Dan_s. I have one more question:
After addition of scg in connected mode, what will happen to scg if UE goes to idle mode will scg remain added or removed and will UE report 5G measurement?
If it goes to idle then it will release both mcg and scg.
Please check this for NSA option 3X end to end scenario:
Before adding the 5G as SgNB, you have to measure And report B1.
But when in idle mode I am getting RF measurement like RSRP, RSRQ etc for lte but not for 5G. When we do speed test etc we get both LTE and 5G RF measurement.
Yes That’s Correct.
The reason why UE is in LTE RRC Idle mode because it has no data to send and receive but it periodically monitors the LTE cell on which it was camped on. But When UE starts data for eg. Speed test It sends a Service Request to LTE and camps on LTE and triggers B1 Measurement report for NR. And NR is Attached. Then you will see LTE and as well NR RSRP.
Please note that you will ONLY see NR measurements when NR is added.
Please refer to How ENDC works with link shared above by @Moniem.
Ok thanks a lot for explanation.
That means there is no such idle mode behaviour for 5G in EN-DC mode.
gNB maintains an Inactivity timer for Every UE, If there is no user data for a particular UE and the Inactivity timer expires, gNB will release NR connection to that UE.
For SA mode as of now UE will monitor 5G in idle mode if SIB24 is configured for LTE to 5G reselection.
Please correct me if it is wrong.
Yes, similar to PBCR from legacy tech. LTE in
NSA - No 5G measurements in Idle
SA - 5G measurements in case of SIB 24
Alternately, there may be requirements or implementations to search for SA without SIB24, i.e. fast return after eps fallback, etc.