I've done some work in this area. We enable the caller to text but all of the data transmission done over the voice channel. This allows for locating the call,

I've done some work in this area. We enable the caller to text but all of the data transmission done over the voice channel. This allows for locating the call, a live conversation and it could be made compatible with all 911 centers. Our users are deaf but anyone could use this. See http://nirmalpatel.com/research/deaf911.html http://nirmalpatel.com/research/deaf911.html