RTT/TTY FAQs

What is Real-Time Text?

Real-time text, or RTT, is a new accessibility solution to replace text telephone (TTY) on Internet Protocol (IP) based networks like Southern Linc's CriticalLinc™ LTE network. When you type something on your phone during an RTT call, your recipient receives your text immediately on a character-by-character basis in near real-time if they also have enabled RTT on their phone. Unlike current text applications that require you to enter a message and then press Send, RTT sends text as you type it.

Is RTT available on Southern Linc?

Yes. RTT is available on the phones listed below. You can enable RTT in the dialer as a choice to select when making a call. In the future, new devices will also be capable of making RTT calls. RTT is available on the Sonim XP8, Samsung S20FE and all new phones introduced on the Southern Linc network after June 30, 2021.

Can I use RTT for an emergency call?

Yes. RTT-TO-911 IS CURRENTLY AVAILABLE on the CriticalLinc LTE network and via Wi-Fi calling for capable devices. When calling 911, always provide the 911 operator your location. If you call 911 via RTT on your RTT-enabled device, the E-911 center will receive your call initially via voice and if you start sending text, your call will be converted to a TTY session with the E-911 center and they will no longer hear sound/voice on your call. RTT-TO-911 calls are subject to the limitations noted below. Today, there are no E-911 centers within Southern Linc's Mission Critical LTE coverage area that can receive information via NATIVE RTT. Similar to Text-to-911 where callers are encouraged to “Call if you Can, and Text if you Can't,” with RTT, please “Call or Text if you Can, and RTT if you Can't.”

For more information on calling or texting to 911 emergency services, visit our 911 and Text-to-911 page at https://www.southernlinc.com/privacy/wireless-accessibility/e911.aspx.

What do I need to know about RTT on my RTT-enabled device?

As you type during an RTT call, the recipient can see you type your message in near real-time without you having to press Send. The recipient must also have RTT enabled on their device. What you need to know when using RTT:

  • You can start using RTT whenever you're communicating with someone whose device also supports RTT or is connected to a TTY device. See below for Limitations of Real-Time Text.
  • To see the RTT option for incoming and outgoing calls, set RTT call option to Always Visible.
  • RTT includes audio, so mute the call if you don't need or want to share audio.
  • RTT calls use voice minutes. Check your rate plan for details.
  • You may call 911 via RTT, but your text will be translated to TTY and is subject to the limitations noted below. In an emergency, you are encouraged if possible to dial 911, or utilize Text-to-911 where available. For more information on calling or texting to 911 emergency services, visit our 911 and Text-to-911 page at https://www.southernlinc.com/privacy/wireless-accessibility/e911.aspx.

How do I get RTT enabled on my phone?

Follow the instructions in this PDF to enable and use RTT on your phone. You can also check for system updates via Settings in your phone.

Limitations of Real-Time Text (RTT)

When you make an RTT call on your RTT-enabled device to 911, TTY users, or to RTT users on some third-party networks, the RTT text will undergo transcoding to TTY. Both parties to the conversation are limited by TTY, which has a more limited character set and may result in the loss of characters, repeated characters or other errors in how the text is displayed to the recipient on both ends of the conversation.

You may contact us at privacy@southernco.com for questions about RTT, or contact Customer Solutions at 1-800-818-LINC (5462) for assistance or troubleshooting any issues you experience.

What are the benefits of Real-Time Text (RTT) over TTY?

  1. For the disability community, RTT can eliminate the need to purchase specialized devices, such as TTY machines, to send text in real-time over wireless devices.
  2. RTT calls use the same ten-digit phone numbers as voice calls.
  3. Both parties to an RTT call can simultaneously send and receive text, unlike TTY, which requires taking turns on who can transmit text.
  4. RTT is more reliable than TTY over IP networks, which means there will be less drop-offs and garbling.
  5. RTT utilizes the full international character set, unlike TTY, which does not allow symbols, emojis and other language characters.