I just got my hands on a Lumia 920 developer build.
The phone idles at "3G". Once there's data, it jumps to "H+". I see this when using IE.
Phone settings: Highest connection speed = 4G, Network selection = automatic, Access point = T-Mobile (active, default, no manual APN added).
MMS (for pictures, at least) works fine with default settings above.
Everything is working fine so far except for tethering. I downloaded and installed the Spanish keyboard. That restarted the phone and installed some updates. I can turn on "internet sharing" and my clients can connect to it just fine.
There is a big problem: The client's (another phone) browser is redirecting all Internet traffic to offers.t-mobile.com, which is asking me to buy the $14.99/month Smartphone Mobile Hotspot. It's rather ridiculous and costs almost as much as my "unlimited" 2GB for $20. My old Lumia 710 internet sharing works fine, and it's always "4G". All of my clients (phone and laptop) can connect to it and use the Internet with the 710.
How can I get Internet Sharing to NOT redirect to the tmobile website? I'm thinking Tmobile is doing this because the 920 can actually connect to HSDPA 42Mbps whereas the 710 is limited to HSDPA 14.4Mbps. This is just a guess.
Summary on Tmobile USA:
Lumia 710
- always 4G
- any phone or laptop can use the Internet Sharing feature
Lumia 920 dev build
- idle on 3G, goes to H+ when data is used
- Internet Sharing can be turned on, but it redirects all client from phones to add hotspot option
- for laptop tethering (non-phone devices), I just get a "Limited" connection error. There's no Internet.