Text Telephony Architecture based upon CTM Friday, August 27, 2010

This arch. digram is from 3GPP TS 26.226 V5.0.0.

there's a like to the standard. http://www.arib.or.jp/IMT-2000/V500Sep06/2_T63/ARIB-STD-T63/Rel5/26/A26226-500.pdf

Based on this digram, you can understand TTY device and mobile phone very well, specially for CTM.

There's a generic icon for TTY