SARA-N310 roaming

Inter Act

Hi,

With regular non-roaming connection the modems register almost instantly to the network. However when the connection is via roaming there is no connection to network. We Have SARA-N310 module that we have tested here in the Netherlands, everything was ok. The module is now in Germany with the same configuration and its not able to connect to the network? any idea why?

remote ip, 172.27.131.100
remote port, 15683
APN, cdp.iot.t-mobile.nl

automatic registration AT+COPS=0

Florian Duecker

@Inter-Act Did you change the PLMN for Germany accordingly? The PLMN ID for Germany is 26201 (instead of 20416 for NL).

Inter Act

@Florian-Duecker

No I have not. I set the registration to automatic not even to AT+COPS=1,2,“20416”. Do I have to set PLMN? even when connection is automatic

# Setup APN for T-Mobile Netherland
AT+QCGDEFCONT="IP","cdp.iot.t-mobile.nl"

# Configure local operator manually: Germany, Telekom
AT+COPS=1,2,"26201" 
# Configure local operator manually: Netherland, T-Mobile
AT+COPS=1,2,"20416" 
# Configure local operator manually: Austria, T-Mobile
AT+COPS=1,2,"23203"

Uta

@Inter-Act if you work on automatic mode, the modem would scan through the whole PLMN until it finds a network. This can take 10 mins or more even on NB-IoT. And Telekom DE is in the PLMN. What is the error code?

Inter Act

@Uta

I don’t know. The modem is in Germany and I in the Netherland. why does it immediately connect to the dutch network?

Florian Duecker

I can second what Uta says. Automatic scanning can take a while as well as a re-attach when crossing borders. Therefore, it is favorable to use a PLMN.

The Dutch network usually attaches the fastest as this is a native T-Mobile Netherlands SIM.

Inter Act

@Florian-Duecker

Thank you, I guess I need to configure the modem.

Jeroen van Bussel

Using manual PLMN selection works if you know in which country your device is (or will be). Otherwise I do not see the benefit of manually selecting the PLMN. And afaik when using AT+COPS you can not set multiple PLMNs

@Uta / @Florian-Duecker - Would it not be possible to have a list of preferred PLMNs stored on the SIM card.

Uta

@Jeroen-van-Bussel of course you can work on automatic mode, the modem would scan through the whole PLMN list until it finds a network. This can take a while and I agree, it’s the only thing that makes sense for devices in non-static use cases.