Performance Assessment of Digital Video Teleconferencing Systems.

Video TeleConferencing VTC is being widely deployed throughout the federal government, achieving great benefits in productivity and timeliness of decisions. The depolyment has resulted from the maturity of video teleconferencing standards, the primary example being the H.32O series of ITU Recommendations. Video compression technology is the fundamental driver of the VTC revolution. The compression is base on digital technology, and the coded output picture is typically characterized by artifacts and distortions which are totally different from those in previous analog TV systems. New artifacts include tiling, jerkiness, mosquito noise, etc. It is very important to measure and specify the end-to-end performance of any telecommunications system, and digital VTC is no exception. Since digital VTC is relatively new, the technology to assess system performance is very new, and the purpose of this document is to summarize the status of this work. This report is divided into two main parts the technical issues and background related to the assessment of NTC performance. VTC applications, uses of assessment techniques, in-service vs out-of-service testing, subjective vs objective tests, analog vs optical interfaces and combined videoaudio assessment.