𝔖 Bobbio Scriptorium
✦   LIBER   ✦

Bandwidth Allocation for the Transmission of Scalable MPEG Video Traffic with Deterministic Guarantees

✍ Scribed by M. Conti; E. Gregori


Publisher
Elsevier Science
Year
2001
Tongue
English
Weight
534 KB
Volume
7
Category
Article
ISSN
1077-2014

No coin nor oath required. For personal study only.

✦ Synopsis


his paper studies bandwidth allocation schemes for the transmission of VBR video traffic with deterministic guarantees, i.e. no packets lost and no missed deadlines. Specifically, we propose and investigate a policy named quasi-constant policy. A VBR encoder attempts to keep the quality of video output constant by varying the transmission rate (constant quality); on the other hand, with a quasi-constant policy the video quality transmission is reduced when congestion occurs. We assume that this reduction is obtained by exploiting source scalability. By characterizing the traffic of a source with a constraint function, we define the relationship between the amount of bandwidth assigned to a VBR source and the maximum delay the application may experience. By applying this relationship to long MPEG 2 traces (more than one hour) we show that the quasi-constant policy is a very promising direction for providing, in an efficient way, a deterministic QoS to VBR video traffic. Specifically, the results presented indicate that with the quasi-constant quality approach we can achieve a utilization greater than 50% with a deadline of one second with only eight reduced-quality frames out of 1000. On the other hand, previous works ([1, 2]) indicate that with a constant quality transmission, a 50% network utilization can be achieved only by tolerating a seven-second deadline.