LTE Link connecting is blocking?

[ExAg]

Hi

In the mqtt_simple example there is a line "modem_configure();" which establishes the LTE Link connection. If connecting the LTE link is not possible (for example no signal), this function never returns.

1. Is this the intention of this function or is there a possibility to configure a timeout?

2. Is it normal, that this function needs several minutes to establish the LTE link, if a provider is present?

regards

ExAg

[ExAg]

Hi Simon

Here are my latest observations according the modem connection time:
I have updated the modem firmware to 1.0.1.
It seems, that the connection time is much faster, if the eval-kit is runnig without debugger. After pushing reset, it takes about 5s to (re)connect the LTE link.
But if I use the debugger, it takes this 1:30 to 6 minutes to connect...

Are there any settings or configurations I have to set up for faster debugging?
(The CONFIG_DEBUG_OPTIMIZATIONS=y is allready set in prj.conf).

Regards
ExAg

[Simon]

Just to make things clear. You are talking about the time between here and here? 

I am not able to reprocuce your behaviour. What NCS tag are you using? Are you using the mqtt_simple example as it is or have you done any changes? 

Best regards,

Simon

[ExAg]

Hi Simon

No, I am not debugging on this low level of libraries (lte_lc.c). I see this behaviour on the line "modem_configure();" in main.c. (mqtt_simple or asset_tracker example does not matter).
If I single step over this line (or set a break point after this line), I see the text "LTE Link Connecting..." in the terminal. From now it takes 1:30 up to 6 minutes, until the text "LTE Link Connected!" appears in the terminal window and I am able to continue with single stepping.

I am using ncs_tag v1.0.0

No, I did not change the code. Its the original code provided by Nordic.

Regards
ExAg

[ExAg]

Hi Simon

I just did some additional testing. I reloaded the mqtt_simple project (this one with TLS from GIT), clean and rebuild the project and downloaded the HEX onto the eval-kit.
My tests are without TLS enabled and without debugger (but it seems to have the same behaviour with the debugger now).
I used the reset button on the eval-kit to restart the application and measured the time between "LTE Link Connecting..." and "LTE Link Connected!".

I have the impression, that it is much better than it was; probably because of the new modem firmware 1.0.1.

Here are the results of 30 resets:

<5s:   25 times
20s:     1 time
1min:   1 time
>7min: 2 times
>9min: 1 time

best regards
ExAg

[Simon]

I am sorry for the delay, I have been sick lately, which is why I haven't been able to answer you. I will look into your issue the next couple of days.

Best regards,

Simon