PBREADY time significantly different between EHS5E vs ESLS61-E R2 | Telit Cinterion IoT Developer Community
January 28, 2022 - 10:52am, 1878 views
Hi,
We are developing devices that are using EHS5E (3G only) and recently moved on to ELS61E-R2 (3G and 4G). We noticed that URC: +PBREADY takes significantly longer in ELS61E-R2 (around 30 seconds after modem power on) compared to EHS5E (8 seconds). Is this expected? Is there any config that can be set to reduce the wait time for +PBREADY? We have battery sensitive device and would like to reduce the modem on time as much as possible. We only use Internet Service and no other service (sms, etc.)
PS: No Sim Pin is required in either of the case.
Thank you.
EHS5-E
REVISION 03.001
A-REVISION 00.000.14
vs
ELS61-E R2
REVISION 02.000
A-REVISION 01.000.05
Hello,
These are 2 different modules so the firmware initialization procedures may differ.
+PBREADY is displayed after SIM PIN authentication has completed and the ME has finished reading data from the SIM, the phonebook and SMS functions are ready for read and write operation.
So this time may also depend on the particular SIM card. Additionally ESLS61-E R2 is 4G (while EHS5E 3G only) and there may be more data to read.
I tried with my ESLS61-E R2 module with 4G SIM and I measured 15 seconds.
Another factor which may probably have influence would be the user application (for instance Java MIDlet) which starts some actions before +PBREADY and could potentially slow down the module initialization.
Please try different SIM for comparison and check if your software is not causing additional delays. There is no way to configure what data is read from the SIM card during the initialization process. So there is no way to directly influence this timing.
Best regards,
Bartłomiej
Hi Bartłomiej,
Thanks for your reply.
We do not have any user application in the modem, so everything in the modem is standard.
It's same long wait time for other SIMs that we use (from the same supplier) that handle global coverage. Is there any detail specs of what are being read from the SIM card? Maybe then I can ask the SIM supplier to remove unnecessary information in order to reduce the read time.
Thank you.
Hello,
I don't have the detailed spec for this now. But I consulted one expert and got some hints.
"There are two factors: The SIM speed and the SIM content.
The SIM speed is negotiated at the very beginning, after the ATR (Answer To Reset), in the PPS procedure. Usually SIM speed is quite fast but what you say sounds like this is a super low cost SIM maybe with a very weak processing capability, therefore negotiating a low SIM interface speed. The SIM speed is a HW-dependent value and can not be modified at all.
The SIM content is defined by the MNO. In a USIM there can be a huge phonebook. The number of files linked to the phonebook can be modified but only by the MNO via Remote File Management (hidden SIM updates with SMS). There is nothing the customer can do, neither about speed, nor about content."
If your organization has access to Thales support system you could create a ticket and then, I think, it might be possible to diagnose what exactly is the problem with your SIM.
Best regards,
Bartłomiej
Hi again Bartłomiej,
I have captured the communication between ELS61E-R2 modem and SIM chip to see how long does it take and how much data is being communicated, and can report that it only takes less than 4 seconds. After that, the 4G modem is quiet for 17 seconds before returning +PBREADY. This indicates that the delay lies within the modem itself and not due to SIM chip. For comparison, EHS5E also takes less than 4 seconds for communication but PBREADY appear right after the communication finished.
Would it be possible for you to look into this further and provide more information why this is the case? And if it is possible to reduce this timing to be closer to 3G modem performance, either via extra AT command, or future modem FW update, or some other methods? For our battery sensitive application, 17 seconds at average 81 mA is quite a lot for every mobile communication. As it stands today we might have to select another modem to preserve battery life, but I would hope there is a better solution out there. Thanks!
Here is the captured signals: https://ibb.co/ZMFWZw7
Hello,
According to my expert PBREADY is generated when the phonebook reading ends. So he rather doubts that the module can do nothing related to SIM reading for 17 seconds and not throw PBREADY.
I checked again with 2 modules and 2 SIM cased. In case of EHS5 it took (from ^SYSLOADING to +PBREADY) from 4 to 8 seconds depending on the SIM. In case of ELS61 it was 10 to 12 seconds.
So I think that there must be some connection between the time and particular SIM and it's contents. So as I suggested before we probably can't do without SIM trace.
And it is a fact that it takes a bit more time for ELS61 than EHS5 to throw PBREADY. In your case it seems to be quite much. But there's no configuration that could affect this directly.
Best regards,
Bartłomiej
Looks like we are not moving forward unless doing a SIM trace. Can you let me know how to get access to Thales support system? Thanks!
You need to contact your local Thales m2m technical sales. Or please try to report the problem to your distributor.