Loss of 4G Statewide?

[joneno]

My Samsung Galaxy S3 has stopped receiving 4g service all over central Indiana which has nearly continuous coverage in 4g. Nothing I do to the phone seems to change that. Replacing the SIM card was suggested but what would that have to do with it?

[Tidbits]

Did someone accidently turned off the LTE radio? Check your network settings to see if you have LTE preferred turned on.

[joneno]

Where do I find that? If I go to settings/ more settings/ mobile netwroks then I get Mobile Data with a green check mark Global Data Roaming Access which is off Network mode which is set to Global and I just switched to CDMA/LTE/EVDO is that it?

[joneno]

And it is still 3g wven though 4g is available where I live.