Videoconference Traffic and Network Design

Recent technological progress is making possible the creation of a new form of videoconference service based on a public network interconnecting private studios located on user premises. We suppose that transmission links in such a network would be reserved in advance by users as and when they arrange their meeting. This and other significant differences with telephony-like services make the use of traditional teletraffic models inappropriate for network dimensioning and performance evaluation. In this paper, we propose an original model of the videoconference reservation traffic process in which essential parameters are the size and distribution of the studio population and the mean studio busy hour utilization rate. This model is used to study certain network architectures in order to identify the effect on link and node dimensions of major design options. First conclusions suggest that the most economical structure might be a simple star network where all studios are connected directly to a central switching facility. Advance reservation makes it possible to employ elaborate routing algorithms, such as call rearrangement, which might be exploited to optimize network or switching node design.