News, Events & Publications     5th ETSI VoIP SQTE successfully completed Print this page
HEAD News - Telecom Division Herzogenrath, 22.04.2009
5th ETSI VoIP SQTE successfully completed Anonymous Report Now Available
  Download here)
For the fifth time the ETSI PlugtestsT Service (European Telecommunications Standards Institute) and HEAD acoustics GmbH as sponsor and test laboratory have carried out the inter- national SQTE ("Voice-over-IP Speech Quality Test Event").
Leading manufacturers of VoIP equipment (gateways, IP phones, IADs, etc.) participated in this test event to comply with latest ETSI specifications and to achieve in-depth analyses of speech quality aspects.
The 5th SQTE continued the success story of the four previous events and again led to a very positive feedback by the participants. In particular, the intensive and mutually fruitful technical discussions between engineers and consultants, the immediate comparison to results from previous events and the excellent organization by the ETSI PlugtestsT Service and HEAD acoustics test team were appreciated by all participants.
The 5th SQTE again provided important guidance to the optimization of speech quality and allowed a benchmark comparison of the devices under test. The test sequences were conducted using the HEAD acoustics communication analysis system   ACQUA and - for the IP phone tests - the artificial head measurement system   HMS II.3. The latest ETSI speech quality standards like the new objective model described in ETSI Guide EG 202 396-3 were used, thus allowing a determination of the status quo in speech quality plus valuable hints, discussions, objective analyses and recommendations for optimization.
Under various network scenarios and test conditions both artificial test signals as well as real speech samples were used. All conversational aspects were accounted for, i.e. quality aspects during single talk as well as during the interaction of both subscribers. The different VoIP configurations were investigated in detail with respect to all parameters relevant to speech quality:
Coder tests under different packet loss rates and jitter conditions
Detailed analysis of PLC (packet loss concealment) and jitter buffer implementations
Quality of background noise transmission, e.g. VAD (voice activity detection) and comfort noise implementations using different kinds of background noises
Double talk performance
Echo canceller implementation: echo loss during single and double talk, convergence and switching characteristics
Transmission characteristics of wideband capable IP phones
Handset and hands-free tests
The huge amount of technical data gathered during the SQTE is summarized in the well- established Quality Pies according to ITU-T Recommendation P.505. Some examples are given on the right and below.
Representation of test results of a Gateway as a "Quality Pie" according to ITU-T P.505
Click here for a detailed view
Representation of test results of an IP phone as a "Quality Pie" according to ITU-T P.505
Click here for a detailed view
Representation of test results of a Gateway as a "Quality Pie" according to ITU-T P.505
Click here for a detailed view
Besides showing the current state-of-the-art of VoIP equipment under controlled IP network conditions (end-to-end as well as mouth-to-ear scenarios), the fact of having their devices tested during the ETSI SQTEs as well as having achieved good test results have become an important marketing tool for the participating manufacturers. This marketing aspect is even more valid now that the test methods in the meantime have developed into new ETSI standards for speech quality evaluation of VoIP equipment (e.g. ETSI Guide EG 202 396-3, ETSI Standards ES 202 -734 to -740 series).
The anonymous test report of the 5th SQTE is now available. Please click    here to download it.
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