RC7620 Faster LTE RRC Idle


Is there a way to configure/reduce the time taken for the RC7620 module to send the RRC release indicaiton to the network after data is sent so it can enter RRC Idle state and sleep? Currently it takes about 5 seconds, but we’ve worked with other modules that can enter a sleep state in about 1s.

Otherwise, is it possible to force the module to sleep without waiting for the RRC inactivity timer?

Have you tried to set to usb selective suspend mode from the host?

Yep, I’ve been able to get the modem to sleep on USB SS. It will sleep immediately if it’s in RRC IDLE (from !GSTATUS), but if !GSTATUS shows RRC CONNECTED there’s a 5s window where the current is 60mA, until it goes into RRC IDLE, at which point the linux host suspends the USB device and current drops to ~4mA.
I think the RRC_CONNECTED->IDLE transition is controlled by the network, but I was hoping there was a way to force the modem into sleep before that transition takes place while maintaining the connection.

is this related to the eDRX mode controlled by AT+CEDRXS?

I don’t think so, I’ve tried different CEDRXS parameters but it doesn’t affect the power consumption in the window we’re interested in. We want to reduce current during the 5s window after network activity stops (I think this is C-DRX mode) but before the module goes to sleep (I think I-DRX/paging mode).
eDRX seems to have a very small impact on the I-DRX/paging mode but doesn’t reduce the current in the 5s of C-DRX.