2014-12-07 12:49 AM - edited 2014-12-07 12:50 AM
It worked "right out of the box" for me - including LTE.
Hope this helps,
2014-12-07 06:52 PM
First off thank you for the reply, as dealing with ATT in my part of the world is worse than a root canal with out pain killers, that said, what kind of visual indications do you recieve that lets you know that you are recieving LTE service
2014-12-07 07:27 PM
Indeed - it is my pleasure!
Sorry to hear about your local AT&T store! By comparision - my local store has been tremendous. I've been a customer since 2007 (first version of the iPhone) and they've been a terrific resource. I'm very biased, however - as they got my one of my iPhones set-up remotely (I was in Haiti during that time) during the earthquake - and post earthquake for rescue and recovery. All calls were free, as was all data - which really assisted while coordinating rescue efforts. Returning to the US was quite impossible - so my local store did it for me remotely...
Anyway - my Z3C came in from HK just after the Sony release overseas. The firmware is a bit different then those imported from the UK, as I understand? Therefore, mine showed "LTE" immediately as opposed to what the UK phones show (only "H+", even on LTE). As well - mine immediately showed H or H+ or LTE depending on the connection. And doing a Spedtest - when running on LTE, had the same throughput as my wife's iPhone 5S on LTE - so, indeed - it was at LTE bandwidth/speed.
Hope this helps and my best always!
2014-12-13 01:50 AM
The above detailed instructions for what to enter worked immediately for me, and that is with using an att micro sim I cut down to a nano.
2014-12-22 03:34 PM
Maybe you don't have the right sub model.. you need D5803. This one is optimal for use in the US.