I tried to look for any spec on this but could not find any useful info.
When the device is in CDRX mode, what happens if the user dials/makes a data call, does the CDRX operation will immediately stop (Whatever the state of the CDRX operation, it could be in On duration/Inactivity timer running or in sleep).
As I know the DRX operation can only be started/stopped by RRC or MAC CE but not any operation inside the Baseband. Please throw some light on this, Thanks in Advance.
Hi @bhonagiri. I have seen in one of Nokia feature release that if UE is in CDRX mode and its MAC layer identifies that RLC buffer has got some priority signalling / data then UE wakes from sleep mode and sends SR request to enb and waits for UL grant (in DL). UE is in Drx active at least for 4ms, if UL grant not received DL inactivity timer started, if UL grant comes then new DRX inactivity timer started from that point.
NOTE - UL tx is done regardless of DRX state (Drx does not affect UL transmitter)
Thank you for great explanation @Saurabh63.
To initiate uplink data traffic, UE has to either send “Scheduling Request (SR)”, or “Buffer Status Report (BSR)” along with CSI-Report, while UE is in awake cycle of CDRX. Here is an explainer video: Energy Saving Techniques for UE in 5G: RRC States, DRX, and CDRX - YouTube
