Is it technically possible for switching between roaming/native networks to maintain a voice phone call? Probably very complicated but is it still possible? I think it would be huge for all the CDMA carriers to invest in making this work, especially now that roaming is generally free with all the carriers. A better solution may be to just change the PRL table that shows all cell sites are part of native network. The carriers should sort out interchanging network charges on the backend, rather than at the handset. Thoughts?