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PLS8: AT+COPS issue in roaming scenario (4G) | Telit Cinterion IoT Developer Community

December 19, 2016 - 6:36pm, 7832 views

Hi,

I have experimented some problems with this command, in a roaming scenario, trying to connect to 4G. For my project, I usually set a RAT restriction (2G/3G/4G) to the module so that I am sure it's not using a technology different than desired for data transmissions. I set the restriction sending the command AT+COPS=0,2,"0",7 where I just care about using the 4G technology, regardless of the operator to be used. In national scenarios it works like a charm, however, I've found a roaming scenario in which this command takes too long to be issued (no response from the module during a while) having to interrupt it before having the response, many *****, after waiting up to 25 seconds. I've also found that, even when the operator selection command is correctly issued (and answered with an "OK"), module is not able to register to the network, AT+CREG? command always return "Not registered, but searching".

I thought it could be a coverage matter, but, if I issue the AT+COPS=0,2,"0", command, the module takes not too much time to correctly register to the network, even using 4G, which was impossible a while before using the more restricting version of the command.

Any idea about the reason for this different behaviours?

Thanks in advance.