What is RTT calling on android?

Today there is no life possible without a smartphone and the Internet. Everyone will be using it intentionally or needlessly. Thus the basic features of a smartphone are familiar to the users, but many of the users are not fully aware of all the features. We are going to introduce a feature called RTT or Real-Time-Text Calling on android. RTT Calling is helpful for instant transmission of a call, by transforming it into a text. It is getting executed thru IP-based technology. 

RTT Calling is a voice-to-text and text-to-voice feature, helpful for those with hearing and speech impairments to communicate with normal people. It can be treated as a substantive tool for the needful people. When the RTT feature available in android phones is enabled on both sides, then no audio signals will be sent in between the two devices. There is no need to hit the key to send as the sending process is done immediately as a person types. This feature is not compatible with all versions of android. RTT is almost similar to a Teletypewriter (TTY). 

What is RTT Calling?

RTT Calling is real-time-text calling, a feature that can be made effective thru smartphones. As the name suggests, a real-time text transmission is performed along with the phone call at the same time. There is no turn-taking and both the functions (multi-party functions) are simultaneously executed without delay. The feature is obviously useful for those having speech and hearing difficulties. Thus the text entered by the two users in a session is transmitted in a time-sampled method (turn).

What is RTT calling on android
What is RTT calling on android?

What is TTY?

A teletypewriter or TTY is a device that establishes communication between people who are suffering from speech and hearing difficulties. It is a text-based communication system. Turn-taking will occur during the transmission.

Difference between RTT and TTY

Even though the functions are almost the same, RTT has more leads than TTY. The internal processes are also different. TTY is operating on a physical device and RTT is operating over the IP address. RTT works with Wi-Fi.   

Pros of RTT over TTY

  • In the process involved in TTY, turn-taking is required. But RTT is instantaneous, and no turn-taking.
  • RTT can operate on Full Duplex mode (simultaneous texting or calling from both ends)
  • In the case of a TTY, an additional device is required, but in RTT Calling no additional device is needed other than an android phone.
  • RTT is more reliable than TTY as the process of calling and receiving is carried out by means of IP Network providers.
  • TTY does not support diverse languages, but RTT supports different languages and emojis
  • Communication flow can be maintained while a conversation is going on and no need to wait for both parties.
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Methods to enable RTT Calling feature in Android Phones

How to enable Real-Time-Text Calling

The RTT Calling feature is developed to overcome the impotence of the TTY devices. The RTT messages are transmitted without making a click on the send button. That is, instantly while typing itself it will be transmitted. RTT call is initiated by the same 10-digit phone number that is used for normal calling. The charges are as per the standards of the carrier networking companies. The application of this technology can be performed only on the Telecomm carriers that support the IP-based technology.

Some of the operating systems have the capability to enable the RTT features automatically. But in some devices, the feature has to be activated thru the phone settings

For enabling Real-Time-Text calling, follow the simple steps: 

  • Switch on the Phone
  • From the Home screen open the Phone App
  • Then tap on the ‘More’ option (three dots)
  • Tap on Accessibility
  • Tap on ‘Settings’
  • Tap on ‘Real-time text (RTT)’ and toggle to set the ‘On’ 
  • Tap on ‘Always Visible’ and toggle to select the ‘On’ position (to make the option visible during a call) 

The activated state makes the RTT device possible to chop and change between a voice and text. Thus once the call is initiated then that can be switched to voice.

Making a Call with Real-Time-Text feature in an android phone

Now the phone has the ‘Always Visible’ option in the ‘On’ stage. Then follow the steps:

  • Open the Phone App on an android phone
  • Select whom to call
    • Can be selected from the saved contacts list
    • From the call logs (if recently called)
    • Can select from the speed dial (from the favorite icon)
  • Tap on the RTT icon (the invitation will be sent to the receiver’s phone)
  • If the recipient on the other side accepted the call, then a text box will appear on the sender’s screen. 
  • Whatever the sender types on the text box, those will be visible to the recipient instantly while typing itself.
  • Usually, during a call, the career options will be in the minimized form.
  • To end the session, maximize the screen and tap on the icon ‘End Call’

Other features of RTT Calling on Android

There is Switch-to-voice call, and Hold options that can be selected during the conversation. Also, the two voice calls and RTT calls can be merged together. The real-Time-Text feature makes the technology a little bit forward and also provides a great user experience, especially for those with hearing and speech impairments.

The Scope of Real-Time-Text Calling

Many Wireless Communication and Networking companies have already attained success in accomplishing the technology involved in Real-Time-Text Calling.  The companies are making supported wireless networks and devices. Also, the RTT plug-ins and effective apps are being developed and launched by many companies. The apps can be pre-loaded and used. The handset should have the compatibility to access this feature when Wi-Fi is enabled.

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The upper hand of RTT eradicates the use of a special dedicated device for real-time texting and incorporates the use of handy wireless phones. Thus it provides greater flexibility in using this feature. Also, it is helpful for the effective use of those who are hard to hearing and incapable of speaking.

Technical Aspects involved in RTT Calling

As per the communication activities of the FCC, (Federal Communication Commission is an independent agency that regulates wired and wireless communications) the device that supports Real-Time-Text needs to be accessible, and operable for people with disabilities. For this, the device should be interoperable, and backward compatible with the TTY technology. as many were used to with the TTY technology.

Real-Time Text (RTT) media is able to handle calls without turns. This is made possible by means of the RTP (Real-Time Transport Protocol) protocol used in a time-sampled mode according to RFC 4103 (RTP Payload for Text Conversation). The call control features are as per the Session Initiation Protocol (SIP). The SIP-based multi-party handling (transmitting from both ends) in the RTT Calling is accomplished by employing a media control unit that controls and coordinates the multiple RTP into one RTP stream. The latency that happens will be around one second from the keypress (of the caller) to the remote receiver.

The RTT Calling system can utilize the same phone number used for national-level calling. The charges apply based on the plan selected from the provider. The character lost during transmission will be marked specifically. The RTT text editing features include deleting characters at the terminal buffer. 

Intimations when a call arrives

RTT terminals are capable to produce distinct types of alerting when a call arrives. The alerting will be visible, audible, and tactile alerting. The tactile alerting is mainly aimed at deaf people. It can be pulsating, rotating, etc. for making them invoke and understand the event. It can be a loud tone, flashing light, or some patterns of vibrations. This can be a BLF (Busy Lamp Field used on devices that employ Voice-over-IP).

RTT Calling support for emergency calls

The service provider of Telecommunications (the carrier) who is providing the RTT Calling, will have to provide the services and facilities to make the emergency call. The system should allow the caller to send and receive the RTT communications to PSAP when an emergency occurs.

PSAPs (Public Safety Answering Points) are responsible for receiving and handling the activities when an emergency call arrives. These are handled as per the specific operating policy. The PSAP is a dedicated call center for answering emergency calls. It is a national-level call center and the number will be different for different countries.

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RTT Calling is a better feature available in android that is specifically useful for hearing and speech impaired people. The feature can be used by enabling the from the phone app settings. It should be made sure that the caller and receiver are enabled the RTT feature. IP-based technology is used in RTT calls. The carrier provider should have the capabilities to accomplish this facility. Also, the phone should have compatibility with this feature. There are facilities for making emergency calls thru the RTT Calling feature. Advanced networking protocols are applied for establishing this for the use of people with disabilities. There are special alerting methods when a call arrives.


What are the advantages of RTT Calling over TTY?

Ans. RTT Calling needs no specialized physical device to be purchased. RTT feature is completely relying on IP-based Technology. The calling and receiving can be accomplished with the normally used phone number. RTT Calling is especially aimed at hearing and speaking impaired people for the effective and easy use of calling and receiving. There are different types of alerts that can be set and used for people with disabilities. It supports Emergency Calling. There is no latency occurring during a call process. Also, RTT supports diverse languages.

How to disable RTT Calling Notifications?

Ans. The RTT notifications can be disabled if you no more need them. The following steps are to be carried out:
-Go to the settings app
-Select Notifications
-Locate Real-Time Text Feature
-Tap the gear icon near to RTT feature
-Toggle to OFF

What is the advantage of RTT calling over a chat or an SMS?

Ans  RTT calling is an advanced feature that works on Network Protocols. RTT feature uses  Full Duplex mode to accomplish simultaneous texting or calling from both parties. No turn-taking occurs. If a chat or SMS is initiated, one has to hit on the Send option. But here the text will be transmitted instantly as a keypress is made from the calling end. The conditions required are
-Both the parties should have the RTT  Calling feature on their smartphones
-Both the systems should have an Internet Connection from 
-the Carriers who provide the facility