Check the symbol representing your signal strength. It's usually better to have more than one network bar.

Can't see a network?

• Check that you are not in airplane mode.
• Check that roaming data is enabled on your device.

For Apple devices: go to Settings, then Cellular data. Then press Options and check that Data roaming is enabled on your device.
For Android devices: go to Settings, then Mobile Network and check that roaming data is enabled.

Not getting enough network?
Test your device in another location with less disruption, preferably indoors.

What do you see now?