If you don't like the idea of buying 4 different usb modems so you cn always browse whenever one network is down, unlocking your current usb modem is the way to go.
Once unlocked, you can insert any NETWORK's SIM and browse with ease.
If you'd like to unlock your modem without being charged a dime, allow me to refer you to strictlyonlinebiz.com/blog/unlock-huawei-zte-usb-modems-free/
Remember this service is FREE OF CHARGE ;-). Cheers
Thanks for giving information.Now i am not able to open this page.Here i want to share my own unlocking experience.
Recently i unlocked my single network locked Huawei mobile phone using network unlock code.I bought an unlock code from Simpleunlocking.com Here i unlocked my Huawei modem within a day and i got free unlock instructions from Mobileunlockguide.com