testing modem - can I force a 3G connection?

[yesitselectric]

I am testing a new modem that is supposed to be 2G/3G, but I seem to only be connecting on 2G (which works completely as expected).

Is there any way to force a 3G connection for testing?

[atok]

Just a hobbyist here but might be able to help depending on the board and chip. Was testing this same thing about a month ago and toggling between 2G and 3G on a SIMCOM 5320 chip (Adafruit FONA3G board). Guessing you’re already sending basic AT commands to the chip using PuTTY or something similar? If you happen to have the 5320 chip see below:

First try:
AT+CNMP?
Thinking you’ll get back a “2” … yes??

Then try:
AT+CNMP=14
What do you get back?
If “OK”, then try:
AT+CNSMOD?
If you get back “0,4” or “1,4” you should be 3G (WCDMA) now.

Then put chip back in “automatic” (2G/3G) mode using:
AT+CNMP=2

If you run into problems let me know, there are other commands to help figure out what’s going on.

[atok]

Just dawned on me since you didn’t mention a specific board/chip that you might have Hologram’s Nova with the u-blox SARA-U201 chip. In that case you want to read up on the AT command AT+COPS (operator selection). See page 95 in the manual below:

u-blox-CEL_ATCommands_UBX-13002752.pdf

With that command you can see what 3G (and 2G) services are in your area and attempt to register with one of them. Note when you type AT+COPS=? to first see all the services available you may be waiting a couple minutes as it gets the info.