Testing of ITU-T G.168 Line-Echo Cancellers Using Matlab-GUIDE

During the last decade echo cancellers became an integral part of many telecommunication systems commercially available. Testing and standardization of such systems, however, is still under development and there are many aspects which have not been counted in. Above all standardization bodies dealing with line echo and its cancellation stands the ITU-T, which has developed and deployed the G.168 Recommendation. The recommendation itself represents a comprehensive set of tests for echo-canceller evaluation. This article addresses problems which might arise during practical implementation of G.168. It also discusses possibilities how to overcome them using Matlab-GUIDE and other tools. In particular, today’s evaluation systems are real-time hardware systems (embedded systems) which are controlled from a local PC or similarly. They are powerful and efficient but they are also very expensive. If we don’t need a real-time solution and if we accept the fact that the process of echo canceller testing would require much more time, we can do all the work off-line using Matlab.