Summary

Recommendation ITU-T P.1305 has the primary purpose of describing the impact of echo-free transmission delays on telemeeting quality of experience (QoE). Delay has a major impact on the interaction performance of conference participants, but is not always explicitly noticed by them; its impact being commonly attributed to other participants behaviour rather than being a system feature.

Before discussing the impact of the delays, it is useful to first consider how people behave when conversing in an ideal environment. Since this has been well studied in the linguistic discipline of conversation analysis (CA), a short discussion of conversations in that context and a discussion on the impact of delay from a CA perspective is included. Some analysis based on the alternative technique of conversation surface structures is also included.

A secondary purpose of this Recommendation is to provide guidance on appropriate testing methods for evaluating the effect of delay in telemeetings.