If your device displays a “No Service” or an “Emergency Calls” only message, this would usually indicate that you are in a location with poor signal strength / limited network coverage.
As a further test however, we would recommend attempting to select a network manually –
1) Go to the ‘Apps’ screen (apps icon looks like 4 white squares making a larger square at the bottom of the ‘Home’ screen)
2) Select “Settings” (icon shows a picture of a gear / cog wheel).
3) Select “More”.
4) Select “Mobile Networks”.
5) Select “Network Operators”.
6) Choose “Select Manually” and wait while the search completes.
7) Try manually selecting one of the networks shown and then retest the service.
8) Please be sure to change the network search mode back to “Choose Automatically” when you move to a new location.