Design and implementation of test a tool for the GSM traffic channel.

• Main Author: Öjerteg, Theo
• Format: Others
• Language: English
• Published: Linköpings universitet, Institutionen för systemteknik 2002
• Subjects: Datorteknik; GSM; speech codec; traffic generation; test tool; test automation; DSP; telecommunication; TSS; encoder; decoder; Computer Engineering
• Online Access: http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-1240

Todays’ systems for telecommunication are getting more and more complex. Automatic testing is required to guarantee quality of the systems produced. An actual example is the introduction of GPRS traffic in the GSM network nodes. This thesis investigates the need and demands for such an automatic testing of the traffic channels in the GSM system. A solution intended to be a part of the Ericsson TSS is proposed. One problem to be solved is that today’s tools for testing do not support testing of speech channels with the speech transcoder unit installed. As part of the investigation, a speech codec is implemented for execution on current hardware used in the test platform. The selected speech codec is the enhanced full rate codec, generating a bitstream of 12.2 kbit/s, and gives a good trade-off between compression and speech quality. The report covers the design of the test tool and the implementation of speech codec. Particularly performance problems in the implementation of the encoder will be addressed.