SIM card access during Idle


I have a concern regarding the SIM card access

here is the test condition

  • module BC660K-GL
  • standart test SIM from R&S
  • Network simulator CMW290 :

When the module wake-up from Sleep period ( DRX or eDRX setting), I don’t see any SIM access while the SIM card doesn’t support suspend mode - Do you know why ?


From deepsleep to wake up, the module will not detect the SIM card status and read. The module will first initiate a service request and register the network. If an error occurs during network registration and SIM card verification, read the SIM card status again (if the SIM card is removed during hibernation).
The module will only detect the SIM card and read information when you power on the module or execute AT+CFUN=0/AT+CFUN=1

For my understanding and based on ETSI TS 131 102 specification, to be able to disactivate the UICC, the EFAD file should be :

  • Byte 1 : ‘01’ normal operation + specific facilities or ‘81’ type approval operations + specific facilities.
  • Bit 4 in byte 3 = 1 ( UICC deactivation in eDRX )

All the SIMs tested doesn’t support ‘specific facilities’, ( the byte 1 is always at ‘0’ ).

So I don’t understand how the BC660K-GL module is able to disactivate the UICC interface during eDRX when UICC support it

Maybe there is additional specification/paper which allow UICC deactivation during eDRX, Thanks to let me know.

If you use eDRX, you need to confirm the events:
1)Check whether the network which the terminal has camped supports eDRX;
2)Check whether the APN of your SIM card supports eDRX;
3)Do you follow at commands to enable eDRX functionality?


The test condition is :
• module BC660K-GL( enable eDRX )
• Test SIM from R&S ( support eDRX)
• Network simulator CMW290 ( configure in eDRX mode )
So all the system are in eDRX mode, and I am able to see the module going to Sleep and wake-up at the expected time.

BUT, as the SIM used doesn’t support ‘specific facilities’ ( EFAD Byte 1 = 0 ), the SIM couldn’t be deactivated during eDRX.
So, I don’t understand why the BC660K-GL module switch off the UICC interface during eDRX.

Maybe, the current FW BC660K-GL didn’t check the EFAD Byte 1 but only the byte 3 ?
Thank to let me know.

By specific facilities, is your goal to study the SIM card features in eDRX status?

My concern is to understand which type of SIM card should be selected to guarantee the best power consumption with BC660.

Based on 3GPP specification (ETSI TS 131 102 reference) , to deactivate the SIM card ( switch OFF the SIM ) during eDRX, the SIM card should report on EFAD file

Byte 1 : ‘01’ normal operation + specific facilities or ‘81’ type approval operations + specific facilities .
( SIM card should support specific facilities )
Bit 4 in byte 3 = 1 ( UICC deactivation in eDRX )

My understanding is that if both bytes are not correctly set, it is not possible to deactivate the SIM during eDRX.

Let me know if you agree with my understanding


Do you have some feedback regarding my topic?

Your research is too in-depth,you are great! At present, if we need to use eDRX, the APN of SIM card needs to support eDRX, and the network also needs to support eDRX features. I am not familiar with EFAD