Powerconsumption with stack turned off

While testing modules (Q26xx/SL6087/SL808xT) and turning off the GSM stack, I noticed one thing that I find a little odd…

The average power consumption for “ACTIVE mode with GSM stack in idle” is LOWER than for “ACTIVE mode with GSM stack turned off” :open_mouth:

If anyone can explain why the consumption is slightly higher when the module is supposed to do less work, go ahead…

Stack turned off with AT+CFUN=4


Please refer to AT command guide, Appendix 3.1 Working mode, for detail information of power consumption mode supported.

For Q268x/SL6087, we should use +WBHV command instead.


Using AT+WBHV=1,1 requires that the module be restarted and prevents further access to SIM commands, while AT+CFUN=4 only turns off the GSM stack and keeps access to SIM commands and don’t require any restart.

In the Working Modes section there is no mention of the specific case I asked about, and even in the PTS document, the power consumption figures indicate that the power consumption is higher with GSM stack off than with it on.

The difference is small enough to not matter much, but it doesn’t seem to make any sense that power consumption is slightly higher with stack turned off.