The big differentiator for RTT over current, commonly-used text-based messaging systems is that RTT messages are sent immediately as they're typed. The FCC said this allows for a more "conversational" exchange, and it also lets people get out partial messages in the case of an emergency. The RTT technology will let text users communicate with people on voice-based phones and vice versa; it can also work easily in your standard smartphone, eliminating the need for specialized equipment.

RTT represents a much-needed upgrade over TTY. As TTY was build to be used on standard landlines, its usage has decreased dramatically in recent years. The FCC also called it limited in speed (it only transmits at 60 words per minute), characters and capabilities. The proposal calls for RTT to roll out over wireless networks run by "larger carriers" by December of 2017.