UMA technology will improve coverage at home with or without the $20 add on feature. This will not only give me great coverage at my house (at the bottom of a hill), won't it also relieve the network traffic on the site outside my house if my calls are going through my Wifi Network? This means less drop calls. I don't have to sign up to pay $20 extra if all I want to do is improve coverage in my home. i think I just need a UMA enabled phone and a router. Nice work, T-Mobile!