GL Announces Enhanced Echo Compliance Testing Software

19th April 2011

ES Admin

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GL Communications Inc. announced today the release of its enhanced Echo Compliance Testing Software - a tool to perform echo cancellation compliance testing automatically per ITU G.168 specification. Speaking to reporters, Mr. Vijay Kulkarni, CEO of the company said, “Echo is annoying. It distorts intelligibility. Unfortunately, it happens in telephone networks, whether in the old PSTN, or in new Mobile and VoIP networks. Echo tolerance is a function of delay – the more delay in the network, the more annoying the echo. It became a major problem with the introduction of satellite voice networks in the late 70’s and 80’s. Equipment manufacturers were addressing echo thru echo suppressors and newly developed echo cancellers. At that time, the CCITT (now called ITU), began a standardization effort to specify the performance and testing of echo cancellers under the spec name “G.165”. It has since been superseded by G.168.”

Speaking to reporters, Mr. Vijay Kulkarni, CEO of the company said, “Echo is annoying. It distorts intelligibility. Unfortunately, it happens in telephone networks, whether in the old PSTN, or in new Mobile and VoIP networks. Echo tolerance is a function of delay – the more delay in the network, the more annoying the echo. It became a major problem with the introduction of satellite voice networks in the late 70’s and 80’s. Equipment manufacturers were addressing echo thru echo suppressors and newly developed echo cancellers. At that time, the CCITT (now called ITU), began a standardization effort to specify the performance and testing of echo cancellers under the spec name “G.165”. It has since been superseded by G.168.”

He added, “In the last 12 years, ITU-T G.168 has undergone many revisions with greater and greater detail and specificity. The latest version of G.168 is G.168 (2009). GL has been keeping up with the improved standards. Currently there are 16 major tests with each test having many subtests and GL has wide gamut of tests supported and can be viewed here: G.168 Tests.”

Mr. Kulkarni explained, “Echo cancellers are sophisticated signal processing devices. Since the echo is somewhat a replica of the original signal in the opposite direction, the EC attempts to subtract a “scaled” version of the replica thereby eliminating the echo. There are many subtleties to the EC process. For example, it should converge quickly, operate in the presence of double talk, work for long or short delays, work for a broad range of signal levels, etc. As Mobile and VoIP networks are also subject to echo, tests have been incorporated for these as well.”

He further added, “Since the EC tests require varying levels of input signals, echo models, delays, and other parameters, the permutations of tests becomes enormous and manual testing a virtual impossibility. GL’s AutoECTest software, however, simplifies the process by allowing the user to input all the variations desired. Literally thousands of tests can be run overnight or over the weekend. The software is used by most all Echo Canceller (EC) manufacturers to simplify the compliance testing of ECs.”