Originally Posted by jcmtyler
However I do not currently have HotSpot access, which would allow me to connect to T-Mobile wifi access points, nor HotSpot@Home (#2), which would allow UMA calls at such access points.
Well, not exactly.
If your account is provisioned normally with a T-Mobile USA voice plan, and if your T-Mobile USA SIM card is in a UMA-capable phone, like your BlackBerry 8900, and if the device is set up and connected to a WiFi connection that allows an IPsec VPN connection back to T-Mobile USA's network over the Internet... then you can not only make UMA calls, you will receive SMS/MMS/PIN messages over UMA and you'll be connected back to your BIS/BES over UMA as well. The minutes used for voice calls will billed exactly the same as minutes over GSM, unless you have the "Unlimited HotSpot Calling" feature.
The "HotSpot" feature is something totally different. If you have this feature, then you'll get an ID and password that you can use to login to T-Mobile HotSpots with any device, typically a laptop. Note that a T-Mobile USA UMA-capable phone will connect to T-Mobile HotSpots for UMA (voice/data/BlackBerry) regardless if you have the "HotSpot" feature or not. I said UMA, which means if you have T-Mobile USA data services, like BIS/BES, then you can get email or web browsing on a T-Mobile HotSpot without any feature code. But, you won't get an IP address for HotSpot web browsing, since you don't have a HotSpot account, but you can browse the web through BIS/BES.
"HotSpot @Home" just means having a WiFi router at home, which T-Mobile USA will gladly sell you. The advantage of having a T-Mobile USA router instead of providing your own is that they support their own routers and can help you when things go wrong. Outside of hints and tips and "it should work" when you have your own WiFi router T-Mobile USA won't be able to help very much if something's wrong.
None of this is to be confused with "T-Mobile @Home", where they can sell you either a "T-Mobile HiPort" WiFi router or adapter that has a SIM slot. You plug in a traditional POTS phone into it, and it connects back to the T-Mobile network using similar protocols to UMA, having T-Mobile essentially provide you your local telephone line instead of your local telco.