T-Mobile: I’m so glad my operator is thinking outside the box

I’ve read about T-Mobile (NYSE: DT) At Home before, but I didn’t know it was going to launch so soon:

The service, often referred to as dual-mode or Unlicensed Mobile Access (UMA), allows a mobile phone to seamlessly switch from cell towers to available WiFi networks when the user comes within range. This would then allow the user to make and receive phone calls via VoIP over the WiFi network—using the same phone number and handset—thereby saving precious cell plan minutes for when there are no WiFi networks available. Other benefits include reduced load on cell networks, increased bandwidth for media streaming and web surfing, and improved call quality over WiFi.

Customers in T-Mobile’s test markets have paid a flat fee of $20 per month on top of their regular service plan fees to use the service, with an additional $5 per line on the account. This pricing structure falls in line with many VoIP services and is lower than the monthly cost of most landlines. However, that pricing structure could change upon national launch, according to the WSJ’s sources. Customers will be able to sign up at T-Mobile retail stores and some retail partners.

I can’t wait! I mainly use my phone at work or at home, both locations have wifi. There are still a lot of questions:

• Will my unlocked, unbranded handsets work with this service? They do have wifi after all.
• Will this work over any wifi network?
• Will you let users use mobile internet while connected to wifi? Let them taste what it is like at home and maybe they’ll sign up for a data plan, just a thought.
• How much bandwidth is needed?