SpringerLink - Journal Article

EPCRTT-based smoothing and multiplexing of VBR video traffic

Ofer Hadar¹, Shlomo Greenberg^{1, 2} and Michael Segal¹

(1)	Communication Systems Engineering Department, Ben-Gurion University of the Negev, Beer-Sheva, 84105, Israel

(2)	Freescale Semiconductor Israel, Herzeliya, Israel

Received: 13 December 2005 Accepted: 27 March 2007 Published online: 15 June 2007

Abstract Applying video smoothing techniques to real-time video transmission can significantly reduce the peak rate and rate variability of compressed video streams. Moreover, statistical multiplexing of the smoothed traffic can substantially improve network utilization. In this paper we propose a new smoothing scheme, which exploits statistical multiplexing gain that can be obtained after smoothing of individual video streams. We present a new bandwidth allocation algorithm that allows for responsive interactivity. The local re-smoothing algorithm is carried out using an iterative process. In the proposed scheme the smoothed video streams are divided into fixed intervals and then a new transmission schedule for each interval is calculated. The problem of applying an optimal transmission schedule for aggregated smoothing video streams is shown to be NP-hard problem. Partitioning the whole stream into sections enables parallel processing of the smoothing algorithm in real-time before transmission. This approach allows partial transmission of the multiplexed stream while smoothing other intervals. The simulation results show a significant reduction in peak rate and rate variability of the aggregated stream, compared to the non-smoothing case. Therefore the proposed scheme allows us to increase the number of simultanusally-served video streams.

Keywords Video rate smoothing - Admission control - Statistical multiplexing gain - Network utilization - QoS

Shlomo Greenberg
Email: shlomog@ee.bgu.ac.il

Ofer Hadar received his B.Sc., M.Sc. (cum laude) and Ph.D. degrees from the Ben-Gurion University of the Negev, Israel, in 1990, 1992, and 1997, respectively, all in Electrical and Computer Engineering. The prestigious Clore Fellowship supported his Ph.D. studies. His Ph.D. dissertation dealt with the effects of vibrations and motion on image quality and target acquisition. From August 1996 to February 1997, he was with CREOL at Central Florida University, Orlando, FL, as a Research Visiting Scientist. From October 1997 to March 1999, he was Post-Doctoral Fellow of the Department of Computer Science at the Technion-Israel Institute of Technology, Haifa. Currently he is a Faculty member at the Communication Systems Engineering Department at Ben-Gurion University of the Negev. His research interests include image and video processing, video compression, MPEG-4: Moving Object separation and tracking packet video, developing of rate control to H.264, transmission of video over IP networks, and video rate smoothing and multiplexing. Dr. Ofer Hadar is a member of IEEE and SPIE.

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Shlomo Greenberg received his B.Sc., M.Sc. (cum laude), and Ph.D. degrees in Electrical and Computer Engineering from the Ben-Gurion University, Beer-Sheva, Israel in 1976, 1984 and 1998, respectively. He has been employed with the IAEC/NRCN, Israel, from 1979 to 1999, and with Freescale Semiconductor Israel since May 2000. Currently he is a Faculty member at the Communication Systems Engineering Department at Ben-Gurion University of the Negev. His research interests include computer vision, image and video compression, transmission of video over wireless, video rate smoothing and multiplexing, digital signal and image processing, object tracking and automatic target detection, pattern recognition, and neural networks. Dr. Shlomo Greenberg is a member of the IEEE.

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Michael Segal received his B.Sc., M.Sc. and Ph.D. degrees in Computer Science from Ben-Gurion University of the Negev in 1994, 1997, and 1999, respectively. During a period of 1999–2000, he held a MITACS National Centre of Excellence Postdoctoral Fellow position at the University of British Columbia, Canada. He then joined the Department of Communication Systems Engineering, Ben-Gurion University, Israel in 2000, where he currently serves as the department’s Chairman. His primary research is algorithms (sequential and distributed), data structures with applications to optimization problems, mobile wireless networks, communications and security.

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EPCRTT-based smoothing and multiplexing of VBR video traffic

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