Data has stopped working

Hi folks.  All of a sudden, the data on my iphone 8 has stopped working.  Never had an issue before, but now I cannot connect to the internet.  I get a message that states "Could not activate cellular data network.  Turn on cellular data or use Wi-Fi to access data.  I've tried restarting the phone, turning data on/off, turning airplane mode on/off, to no avail.  Is the data network down perhaps?  I'm currently in the LA area for work, but it was working about fifteen minutes ago.

Thanks in advance.