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GSM Roaming control | Telit Cinterion IoT Developer Community

June 6, 2016 - 12:01pm, 7666 views

Hello,

I have some questions regarding roaming in TC65(i) modems (and eventually EH6x) as we currently experience issues with modems deployed (static) closed to country borders. The SIM cards involved there are generally enabled on roaming-data for commissioning and debugging but should ideally never use it during normal operation.

(1) What we "simply" want to do is tell the modem+SIM to stick to its local preferred operator (for data and SMS mainly, we do not use voice)..

- either always  (so even if cell quality is bad or inexistent)

- or as much as possible / as long as a data connection is possible  (switch to roaming - international only as last resort and not at the first association error encountered for example)

What is the simplest way (if any) to do that?

Related questions:

(2) I don't know what are the thresholds (bearer quality, BER, RSSI, .. ) that trigger a switch to another operator (roaming or not) ? are they (easily) configurable? 

(3) On EHS6x modems AT command set we can see the following command: AT^SCFG="MEopMode/SoR" (with SoR mode enabling or disable steering of roaming). What is the exact purpose of this command? When to use it?

(4) In contrary I don't have seen any AT command relating to roaming (except those reading the roaming status) in TC65(i) modems. Am I missing something? Are we meant to use the CPOL and CPLS commands to inhibit other operators? Is it safe to do that on the long term (eg. in case of on-site topology change or new operator, or even some kind of renaming) ?

Could you please share experience and preferred solutions for the mentioned use case and the related questions?

Regards,

Bruno