Echo Cancellation


The ECT tester is a result of several years of development in co-operation with BT Laboratories and echo cancellers manufacturers to provide a real time automated and reliable test environment.

The ECT is unique among other available test equipment with a number of distinctive features as listed below:

  • Provides a “one stop shop” solution for all Echo Canceller related testing with all test suites operating in real time with the processing and precise timing implemented in the DSP hardware.
  • Provides fully interactive real time subjective Echo Canceller testing with either emulated ITU-T network conditions – as selected by the user – OR real PSTN and Mobile Networks.
  • Provides full implementation of Objective Conformance testing against all versions of the G.168/xx ITU-T Recommendation.
  • Provides full automation and repeatability of tests in Multimode Test Mode (MTM). Various test parameters such as Echo Path Delay, ERL and others can be set by the user and all selected G.168xx tests repeated continuously over a period of days or weeks within specified parameters range and resolution. Results of each test are stored in numerical and graphical format with pass and failure indications. That way stability of the Echo Canceller over period of time and under various network conditions for some or all of G.168xx tests can be positively verified.
  • Optionally ECT1 provides an extensive range of verified real time Network models available as down-loadable real time software modules such as Voice Codecs (G.726, G.729, G.728, FR GSM, etc), I/P connections, DCME etc that can be used for Subjective or objective testing of Echo Cancellers.
  • Provides a variety of optional I/O interfaces (apart from standard E1 & T1), fully integrated into ECT architecture such as 4-wire analogue, 2-wire analogue, POTS, BRI ISDN and High-resolution A/D & D/A analogue. Customised I/O interfaces such as direct TTL level 2.048, 4.096 Mbits TDM data streams are also available.
  • Provides an extensive library of optimised and verified (with original equipment manufacturers) control drivers for almost all commercially available Echo Cancellers. That library allows a meaningful performance comparison between different Cancellers in the optimal set-up conditions. It has to be noted that the improper set up of the control driver by e.g. not taking into account command delay due to the command processing time will produce misleading test results.