I have 4 different types of USB 3G modems from Europe. They're not operator locked. I'm trying to use them on an American network for 3G connectivity.
Even though they state "850, 900, 1800, 1900 MHz" bands in their specs, and my network supposedly has UMTS on 850 MHz, I can only get a 2G (EDGE) connection and furthermore, they all detect my SIM card as out of network and put me in "roaming" mode.
I've found out that the radios in these things are usually universal but the band limits are only in software. Therefore I was wondering if there would be any way (through undocumented AT commands or firmware flashing) I could get either one of these modems to switch allowed bands and let me get 3G speeds in North America.
Are there any resources where I can get AT command lists and/or different region firmware for these devices? Or is there anyone that could maybe point me in the right direction?
These are the devices I have:
- Huawei E3131
- Huawei E353
- ZTE MF190
- D-Link DWM-156
I tried flashing different versions of firmware and/or googling AT commands to change bands on some of these, but at the end, the moment I switch mode to 3G I get "no service"
Any help would be greatly appreciated...