Introduction

22.2263GPPGlobal Text Telephony (GTT)Release 17Stage 1TS

Real time, character by character text conversation is a component that increases usability in a conversational session.

Global Text Telephony is a feature that adds the capability to use a text conversation component in a session. It is called Global Text or GTT here.

Interworking with corresponding features in other networks is an important part of Global Text. Specifically, the different kinds of PSTN text telephone systems supported by the international text telephone modem standard ITU-T V.18 are included in the modes for interworking.

One important reason to offer the Global Text feature is to enable emergency service access to people who are depending on a written dialogue.

A more elaborated background is found in Annex A, and requirements in Annex B.

Figure 1 gives an overview of the user environment for Global Text.

Figure 1. Global Text service environment