An Eecient Solution to Traac Characterization of Vbr Video in Quality-of-service Networks

A network that ooers deterministic, i.e., worst-case, quality-of-service (QoS) guarantees to variable-bit-rate (VBR) video must provide a resource reservation mechanism that allocates bandwidth, buuer space, and other resources for each video connection. Such a resource reservation scheme must be carefully designed, otherwise network resources are wasted. A key issue for the design of a resource reservation scheme is the selection of a traac characterization that speciies the traac arrivals on a video connection. The traac characterization should accurately describe the actual arrivals so that a large number of connections can be supported, but it must also map directly into eecient traac policing mechanisms that monitor arrivals on each connection. In this study, we present a fast and accurate traac characterization method for stored VBR video in networks with a deterministic service. Our characterization approach approximates the so-called empirical envelope of a video sequence. We use this approximation to obtain a traac characterization that can be eeciently policed by a small number of leaky buckets. We present a case study where we apply our characterization method to networks that employ a dynamic resource reservation scheme with renegotiation. We use traces from a set of 25-30 minute MPEG sequences to evaluate our method against other characterization schemes from the literature.