Guobin Shen, Changxi Zheng, Wei Pu and Shipeng Li
Distributed Segment Tree: A Unified Architecture to Support Range Query and Cover Query.
Technical Report MSR-TR-2007-30, 2007
Paper (PDF) Changxi Zheng, Guobin Shen, Shipeng Li, and Scott Shenker
Distributed Segment Tree: Support of Range Query and Cover Query over DHT.
The 5th International Workshop on Peer-to-Peer Systems (IPTPS) Santa Barbara, US, February 2006
Paper (PDF) Abstract Bibtex Range query, which is defined as to find all the keys in a certain
range over the underlying P2P network, has received a lot of
research attentions recently. However, cover query, which is to
find all the ranges currently in the system that cover a given key,
is rarely touched. In this paper, we first identify that cover query
is a highly desired functionality by some popular P2P applications,
and then propose distributed segment tree (DST), a layered DHT
structure that incorporates the concept of segment tree. Due to
the intrinsic capability of segment tree in maintaining the sturcture
of ranges, DST is shown to be very efficient for supporting both
range query and cover query in a uniform way. It also possesses
excellent parallelizability in query operations and can achieve O(1)
complexity for moderate query ranges. To balance the load among
DHT nodes, we design a downward load stripping mechanism that
controls tradeoffs between load and performance. We implemented
DST on publicly available OpenDHT service and performed extensive
real experiments. All the results and comparisons demonstrate
the effectiveness of DST for several important metrics.
@inproceedings{Zheng06DST,
author = {Changxi Zheng and Guobin Shen and Shipeng Li and Scott Shenker},
title = {Distributed segment tree: Support of range query and cover query over dht},
booktitle = {In proceedings of the 5th International Workshop on
Peer-to-Peer Systems (IPTPS 06)},
year = {2006}
}
Ke Liang, Zaoyang Gong, Changxi Zheng, and Guobin Shen
MOVIF: A Lower Power Consumption Live Video Multicasting Framework over Ad-hoc Networks with Terminal Collaboration.
International Symposium on Intelligent Signal Processing and Communication Systems (ISPACS), Hong Kong, December 2005
Paper (PDF) Abstract Live video multicasting over wireless ad hoc networks is a tough
problem due to the restricted computational ability of the mobile
devices and non-predictive networks status. In this paper,
we propose MoViF, a lower power consumption multicasting framework
for live video multicasting over ad-hoc networks. The proposed
MoViF adopts distributed video coding (DVC) scheme and, as a
result, enjoys all the beneï¬ts of DVC such as lightweight encoder
and built-in error resilient capability. Moreover, MoViF manages
to apply an elegant strategy to minimize the overall power consumption
for all the receivers while improving their decoding quality by
dynamically assign the tasks of aid information extraction to
some intermediate powerful nodes in the multicast tree.
Simulation results demonstrate that the optimal strategy can lower down
the overall power consumption comparing to the random strategy.
Changxi Zheng, Guobin Shen, and Shipeng Li
Distributed Prefetching Scheme for Random Seek Support in Peer-to-Peer Streaming Applications.
Workshop on Advances in Peer-to-Peer Multimedia Streaming, ACM Multimedia 2005, Singapore, November 2005
Paper (PDF) Abstract Bibtex Through analysis of large volume of user behavior logs during
playing multimedia streaming, we extract a user viewing
pattern. The pattern indicates that random seek is a pervasive phenomenon,
contrary to the common assumptions that
users would watch a video session sequentially and passively
in most works on peer-to-peer streaming. We propose to use efficient
prefetching to facilitate the random seek functionality.
Because of the statistical nature of the user viewing
pattern and the ignorance of the users to the content, we
argue that the pattern should be used as a guidance to the
random seek. Based on the pattern, we set up an analogy
between the optimization problem of minimizing the seeking
distance and the optimal scalar quantization problem. We
then propose an optimal prefetching scheduling algorithm
based on the optimal scalar quantization theory. We further
propose a hierarchical prefetching scheme to carry out
the prefetching more effectively. Real user viewing logs are
used to drive the simulations which demonstrate that the
proposed prefetching scheduling algorithm and the hierarchical
prefetching scheme can improve the seeking performance significantly.
@inproceedings{zheng2005distributed,
title={Distributed prefetching scheme for random seek support in peer-to-peer
streaming applications},
author={Zheng, Changxi and Shen, Guobin and Li, Shipeng},
booktitle={Proceedings of the ACM workshop on Advances in peer-to-peer multimedia streaming},
pages={29--38},
year={2005},
}
Changxi Zheng, Guobin Shen, and Shipeng Li
Segment Tree Based Control Plane Protocol for Peer-to-Peer On-Demand Streaming Service Discovery.
Proc. of Visual Communication and Image Processing (VCIP), Beijing, China, July 2005
Paper (PDF) Abstract Bibtex As the intense academic interest in video streaming over peer-to-peer(P2P)
network, more and more streaming protocols have been proposed to address
different problems on this field, such as QoS, load balancing, transmission
reliability, bandwidth efficiency, etc. However, to the best of our knowledge, an
important component of any practical P2P streaming system, the streaming
service discovery, is rarely granted particular considerations, which is to
discover potential peers from which a newcomer could receive the requested
stream. In this paper, we are inspired from a special data structure, named
Segment Tree(ST), and propose a protocol to address this problem specifically.
Furthermore, we fully decouple the control plane and data plane on video
streaming, and hence provide more flexibilities in designing protocols on both
of them.
@inproceedings{Zheng05VCIP,
author = {Changxi Zheng and Guobin Shen and Shipeng Li},
title = {Segment Tree Based Control Plane Protocol for Peer-to-Peer
On-Demand Streaming Service Discovery},
booktitle = {In proceedings of Visual Communication and Image Processing (VCIP)},
year = {2006}
}
Changxi Zheng, Guobin Shen, Shipeng Li and Qianni Deng
Joint Sender/Receiver Optimization Algorithm for Multi-Path Video Streaming Using High Rate Erasure Resilient Code.
Proc. of IEEE International Conference on Multimedia and Expo (ICME), Amsterdam, Netherlands, July 2005
Paper (PDF) Abstract Bibtex In this paper we present a joint sender/receiver optimization algorithm and a
seamless rate adjustment protocol to reduce the total number of packets over
different paths in a streaming framework with a variety of constraints such as
target throughput, dynamic packet loss ratio, and available bandwidths. We
exploit the high rate erasure resilient code for the ease of packet loss
adaption and seamless rate adjustment. The proposed algorithm and adjustment
protocol can be applied at an arbitrary scale. Simulation results demonstrate
that the overall traffic is significantly reduced with the proposed algorithm
and protocol.
@inproceedings{Zheng05ICME,
author = {Changxi Zheng and Guobin Shen and Shipeng Li and Qianni Deng},
title = {Joint Sender/Receiver Optimization Algorithm for Multi-Path Video Streaming
Using High Rate Erasure Resilient Code},
booktitle = {IEEE International Conference on Multimedia and Expo (ICME)},
month = July,
year = {2005}
}