6 The goals and objectives

26.2263GPPCellular text telephone modemGeneral descriptionRelease 17TS

CTM is developed to provide a solution that:

– meets the FCC Emergency Call (911) requirements for Text Telephony;

– meets the requirements for a Global solution for Text Telephony;

– works with GSM AMR, EFR, and FR codecs, as well as future codecs;

– is applicable for existing and future speech traffic channels in GSM and UMTS;

– minimizes the impact to existing or future cellular networks;

– allows roaming between networks of different operators;

– provides a transmission rate of 10 characters per second according to a net bit rate of 80 bit/s;

– does not introduce an additional delay of more than 800 ms for text transmission;

– does not have any impact for voice transmission, i.e. speech signals must not be distorted or delayed.