MC8355: How to enforce 2G|3G?

IoT Modules MC/EM Series
1

Using the MC8355 in a Windows 7 system, how can I enforce the module to establish only 2G connections, no 3G connections?
Are they any configuration files or registry settings which control this?

From the Sierra Wireless resource area, I’d expect the “Airprime MC Series Connection manager DIP build 3830” to do such settings but according the download page, it’s dedicated to “MC809x, MC870x,MC7700/MC7710 (Direct IP)” only (MC8355 is not mentioned).

Background: The Windows 7 system with the MC8355 is running an application with low bandwidth requirements and shall be used at various places where 2G coverage is probably better than 3G coverage.

2

Hi Alexander,

Normally, you can leave it to decide whether to use 2G or 3G based on network coverage at the location.

But if you really want to force it, the QMI version of connection manager may work:
http://source.sierrawireless.com/resources/airprime/development_kits/airprime-mc-series-connection-manager-qmi-build-4202/

Beside, you may also try AT cmd $QCBANDPREF.

Hope it helps.

3

Hi lotam,

thank you for your reply. I tried Skylight_Generic_Build4260.msi, but it did not stop searching (i.e. did not find any network). It id allow only to change the Network Selection Mode (either “Automatic” or “Manual”) but did not allow to change the Radio Technology.

Then I tried Watcher_Generic_Build_3830.msi. This indicated the SIM card provider, finds a network and allows to change the Network Selection Mode (either “Automatic” or “Manual”) and the Radio Technology (either “UMTS/GSM” or “LTE/legacy 3GPP mode”). First, this appeared not helpful since the 1st option allows both 2G and 3G and since the MC8355 doesn’t support LTE. But to my surprise Radio Technology = “LTE/legacy 3GPP mode” brings up another option where I can select either “2G only”, “3G only” or “2G/3G”.

So with the above utility version we hopefully can now can make separate tests with 2G and 3G.

Best Regards
Alexander

4

Hi lotam,

one further request: Can you suggest how to make “3G only” permanent by an automatic installation procedure (script)? I think of something like

  • setting a Windows 7 registry key through a script or
  • submitting an appropriate AT command to the device through a script.

AFAIK, the Watcher utility and terminal software like PuTTY have no option to submit predefined commands in an unattended mode(?).

Thanks in advance for your help.

Best Regards
Alexander

5

Hi Alexander,

Sorry, I think this is very use case and host specific.

I don’t think it can be done via registry alone.
But it is possible using script (AT cmd) or simple program using QMI.

Hope that help.
Thx

6

Hi lotam,

the command $QCBANDPREF you suggested doesn’t work with our AirPrime MC8355. I started submitting first the queries AT$QCBANDPREF? and AT$QCBANDPREF=? but the result is ERROR. Other basic query commands (like e.g. ATI or AT&V) work and provide a plausible result. Do you have another suggestion?

Best Regards
Alexander