Mobile devices are usually pretty clever at automatically selecting the most appropriate network for you.
However, if your service isn't working as it should, or you’re on the fringe of coverage, forcing your device to a particular network mode (eg. 4G or 3G) can be a useful troubleshooting step. It'll help you check whether the issue is related to a specific network type, and might even serve as a workaround in the meantime.
Switching down to 3G may also help to conserve your battery if you're running low, but we'd suggest leaving the network mode setting on automatic whenever possible.
You can change the network mode by doing the following:
iOS:
- Open “Settings”.
- Select “Mobile”.
- Select “Mobile Data Options”.
- Select "Voice & Data"
- Choose your desired network from 3G or 4G (if supported by your handset)
Android:
- Open “Settings”
- Select “Mobile Networks” under the Wireless & Networks category
- Select “Preferred network type”
- Choose your desired network from 3G or 4G (if supported by your handset)