 |
Ph.D. Research
Thesis
Ali C. Begen, "Enhancing the multimedia experience in emerging
networks," Ph.D. Dissertation, Georgia Institute of Technology, Atlanta,
GA, Dec. 2006 [pdf]
Research Projects
The following is a list of research projects I worked on at Georgia Tech.
These projects were funded by the following agencies:
Related Publications:
-
Ali C. Begen, Mehmet A. Begen, Yucel Altunbasak and M.
Reha Civanlar, "Proxy selection for interactive video," in Proc. IEEE
Int. Conf. Communications (ICC), Istanbul, Turkey, June 2006 [pdf]
-
Ali C. Begen and Yucel Altunbasak, "Proxy-assisted
interactive-video services over networks with large delays," EURASIP
Signal Processing: Image Communication, Special Issue on Video
Networking, vol. 20/8, pp. 755-772, Sept. 2005 [pdf]
-
Ali C. Begen, Yucel
Altunbasak, M. Reha Civanlar and Gokce Gorbil, "High-resolution video
streaming in mesh-networked homes," in Proc. IEEE Int. Conf. Image Processing (ICIP),
Genoa, Italy, Sept. 2005 [pdf]
-
Ali C. Begen and Yucel Altunbasak, "Videoconferencing over
an intermediate-proxy," in Proc. IEEE Int. Conf. Image Processing (ICIP),
Singapore, Oct. 2004 [pdf]
[Back to top
 ]
In delay-sensitive real-time streaming applications,
when a packet is not delivered within an expected amount of time, an
important issue is to determine whether the missing packet is merely delayed
or is already lost. Historically, inherited from TCP jargon, the duration
after which the missing (or unacknowledged) packet is assumed to be lost is
referred to as retransmission timeout (RTO). Regardless of doing a
retransmission or not, timely inference of late/lost packets is crucial for
real-time streaming applications, so that well-timed actions can be taken by
the server/client. In this project, we first investigate several methods
that can help us understand the packet dynamics in real-time streaming
applications. Then, we integrate these methods into different
error-control/protection methods, and demonstrate that streaming quality can
be substantially improved without requiring complex computations.
Related Publications:
-
Ali C. Begen and Yucel Altunbasak, "Media-aware
retransmission timeout estimation," in Proc. IEEE Int. Conf.
Acoustics, Speech and Signal Processing (ICASSP), Honolulu, HI, Apr. 2007 [pdf]
-
Ali C. Begen and Yucel Altunbasak, "An
adaptive media-aware retransmission timeout estimation method for
low-delay packet video," IEEE Trans. Multimedia,
vol. 9/2, pp. 332-347, Feb. 2007 [pdf]
-
Ali C. Begen, Mehmet A. Begen and Yucel Altunbasak,
"Predictive modeling of video packet delay in IP networks," in
Proc.
IEEE Int. Conf. Image Processing (ICIP), Atlanta, GA, Oct. 2006 [pdf]
-
Ali C. Begen and Yucel Altunbasak, "Redundancy-controllable
adaptive retransmission timeout estimation for packet video," in Proc. ACM Int. Wksp. Network and Operating Systems Support for Digital
Audio and Video (NOSSDAV), Newport, RI, May 2006 [pdf]
-
Ali C. Begen and Yucel Altunbasak, "Estimating packet
arrival times in bursty video applications," in Proc. IEEE Int.
Conf. Multimedia and Expo (ICME), Amsterdam, The Netherlands, July
2005 [pdf]
-
Ali C. Begen and Yucel Altunbasak, "Timely inference of
late/lost packets in real-time streaming applications," in Proc.
Picture Coding Symp. (PCS), San Francisco, CA, Dec. 2004 [pdf]
(Invited paper)
[Back to top
]
In this project, we study the streaming of
packetized media from multiple servers to a client over a wireline lossy
network. In particular, we propose a client-driven rate-distortion optimized
scheduling method that selects which packet(s) to be requested from which
server(s) at a given request opportunity. In doing so, the proposed
scheduling algorithm not only attains the maximal presentation quality but
also conforms to the rate constraints dictated by the TCP-friendly flow,
window and congestion control mechanisms. We provide the simulation results
for an extensive range of scenarios to demonstrate the efficacy of the
proposed algorithm.
Related Publications:
-
Ali C. Begen, Mehmet U. Demircin and Yucel Altunbasak,
"Packet scheduling for multiple description video streaming in
multipoint-to-point networks," in Proc. IEEE Int. Conf. Communications
(ICC), Paris, France, June 2004 [pdf]
-
Mehmet A. Begen, Ali C. Begen and Yucel Altunbasak, "Packet
scheduling for real-time video streaming with mathematical programming,"
in INFORMS Telecommunications Conf., Boca Raton, FL, Mar. 2004 (Abstract only)
-
Ali C. Begen, Yucel Altunbasak and Mehmet A. Begen,
"Rate-distortion optimized on-demand media streaming with server
diversity," in Proc. IEEE Int. Conf. Image Processing (ICIP),
Barcelona, Spain, Sept. 2003 [pdf]
(Best student-paper award)
[Back to top
]
Real-time media distribution over the Internet poses
several challenging problems due to its stringent delay/loss requirements
and complex network dynamics. A promising approach to alleviate the severe
impacts of these dynamics is to transmit the media over diverse paths. For
such an environment, Multiple Description Coding (MDC) has been previously
proposed to produce multiple independently-decodable streams that are routed
over partially link-disjoint (non-shared) paths to combat bursty packet
losses and error propagation. Nevertheless, selecting these paths
appropriately is fundamental to the success of MDC and path diversity.
Hence, in this project we propose a multi-path selection method that chooses
a set of paths maximizing the overall quality at the client under various
constraints. The simulation results with MPEG-2 show that sizeable average
peak signal-to-noise ratio (PSNR) improvements (ranging from 0.73 dB to 6.07
dB) can be achieved when the source video is streamed over intelligently
selected multiple paths as compared to over shortest path or maximally
link-disjoint paths. In addition to the PSNR improvement, end-users
experience a more continual, i.e., uninterrupted, streaming quality.
Our work also considers the architecture and mechanisms by which path
selection may be accomplished in an application-aware environment.
Related Publications:
-
Ali C. Begen, Yucel Altunbasak, Ozlem Ergun and Mostafa H.
Ammar, "Multi-path selection for multiple description video streaming
over overlay networks," EURASIP Signal Processing: Image
Communication, vol. 20/1, pp. 39-60, Jan. 2005 [pdf]
(Most-cited paper award)
-
Ali C. Begen, Yucel Altunbasak and Ozlem Ergun, "Fast
heuristics for multi-path selection for multiple description encoded video
streaming," in Proc. IEEE Int. Conf. Multimedia and Expo (ICME),
Baltimore, MD, July 2003 [pdf]
-
Ali C. Begen, Yucel Altunbasak, Ozlem Ergun and Mehmet A.
Begen, "Real-time multiple description and layered encoded video streaming
with optimal diverse routing," in Proc. IEEE Int. Symp. Computers and
Communications (ISCC), Antalya, Turkey, June 2003 [pdf]
-
Ali C. Begen, Yucel Altunbasak and Ozlem Ergun, "Multi-path
selection for multiple description encoded video streaming," in Proc.
IEEE Int. Conf. Communications (ICC), Anchorage, AK, May 2003 [pdf]
[Back to top
]
Grant Proposal Contributions
I have contributed to the following research proposals:
-
"Enhancing the multimedia experience in emerging networks:
rate-distortion optimization in multimedia networking," funded by
National Science Foundation (NSF)
for three years, PI: Yucel Altunbasak, 2004
-
"Cross-layer approaches for interactive media streaming,"
funded by National Science Foundation (NSF) for three years, PI: Yucel Altunbasak, 2003
-
"Rate-distortion optimized on-demand media streaming in
multipoint-to-point networks," funded by Georgia Tech Broadband
Institute (GTBI) for two years, PI: Yucel Altunbasak, 2003
Internship
For summer and fall 2004, I had an internship at
Qualcomm (Standards
Engineering Group) in San Diego, CA. The following documents give an overview of
my internship work:
- Ali C. Begen and Alkinoos Vayanos, "Analysis of enhanced radio link
control for W-CDMA networks," in IEEE Int. Conf. Computer Communications
(INFOCOM), Miami, FL, Mar. 2005 [pdf]
[Poster]
-
"RLC status reporting enhancements," 3GPP TSG RAN WG2 Meeting
#45bis (R2-050095), Sophia Antipolis, France, Jan. 2005
-
"HARQ/PHY requirements," 3GPP TSG RAN WG1 Meeting #38
(R2-041650), Prague, Czech Republic, Aug. 2004
|
