Restrict Operator Selection

Robert Colvin punk.spot9096 at skrapost.net
Sun Mar 12 10:20:47 UTC 2023


hi Attie

sorry, bit late on this one; as someone who works in the Cellular IoT industry, I would advise you to think carefully about manually setting networks - it might be the best solution for you, however you might also look to talk to your operator about using, for example, steering lists or other mechanisms that allow you to steer to cheaper networks but keep your modem in auto mode; being in manual mode is probably one of the biggest causes i see for devices being unreachable (if the network you are connected to is not available, you are responsible in your firmware to choose another network; in auto mode your operator can, via OTA, update steering lists - depending on your operator)

as I say, for your operator, sim and use case this might be the best option, but please consider other options as well :) 

-- 
  Robert Colvin
  punk.spot9096 at skrapost.net

On Wed, Mar 1, 2023, at 1:18 PM, Attie Grande wrote:
> Hi Aleksander,
>
> Many thanks for your reply - I'll give it a go!
>
> Attie
>
>
> On Fri, 24 Feb 2023 at 17:35, Aleksander Morgado
> <aleksandermj at chromium.org> wrote:
>>
>> Hey,
>>
>> >
>> > We have some devices in far away locations, using roaming IoT-focused SIM cards.
>> > In some situations we find that modems will roam to very expensive
>> > networks, when a cheaper alternative is available in that area.
>> >
>> > Is there an interface to set the operator MCC / MNC via `mmcli`?
>> > The AT command would be `AT+COPS=1,2,${MCCMNC}`, but you can't issue
>> > AT commands unless debug mode is enabled.
>> >
>> > From the documentation, I'm not convinced
>> > `--3gpp-register-in-operator=MCCMNC` is what I'm after...
>> > i.e: does it do the equivalent of above? ... is it a "one-time
>> > request" or even a "try manual, fallback on auto".
>> > If this is indeed what I'm after, but it needs to be issued
>> > periodically, then that's fine.
>> > Equally, if it's persistent, how would we cancel this? (reboot / power
>> > cycle the modem?)
>> >
>>
>> --3gpp-register-in-operator=MCCMNC should be equivalent to
>> AT+COPS=1,2,${MCCMNC} (i.e. manual registration)
>> --3gpp-register-in-home should be equivalent to AT+COPS=0 (i.e. auto
>> registration)
>>
>> Now, that is not completely true I'm afraid, because when those APIs
>> were developed, I recall that we introduced a change where we would
>> say 'if we're in auto and we're asked to register in a specific
>> MCCMNC, we won't issue a new +COPS command to explicitly restrict to
>> that MCCMNC as we're already registered'. I think someone tried to fix
>> that some years ago to make it equivalent to the COPS command without
>> that extra logic, but I don't think it was ever changed. We should
>> change that.
>>
>> --
>> Aleksander


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