Biography                                                                                               

Research & Engineering Interests                                                       

Publications                                                                                          

PhD Thesis:

• Thesis: " Research on Peer-to-Peer Live Streaming Scheduling Algorithm". In Chinese.

• " PhD Defense Slides". In English.

Journal Papers:

• Meng ZHANG, Yongqiang XIONG, Qian ZHANG, Lifeng SUN, and Shiqiang YANG. " Optimizing the Throughput of Data-Driven Peer-to-Peer Streaming". In IEEE Transactions on Parallel and Distributed Systems, Volume 20, Issue 1, January 2009

• Meng ZHANG, Qian ZHANG, and Shiqiang YANG. " Understanding the Power of Pull-based Streaming Protocol: Can We Do Better?". In IEEE Journal on Selected Areas in Communications, special issue on Advances in Peer-to-Peer Streaming Systems, Vol. 25, No. 8, December 2007

Conference Papers:

• Meng ZHANG, Lifeng SUN, and Shiqiang YANG. " iGridMedia: Providing Delay-Guaranteed Peer-to-Peer Live Streaming Service on Internet". Accepted by IEEE GLOBECOM 2008. (IEEE GLOBECOM'08)

• Meng ZHANG, Qian ZHANG, Lifeng SUN, and Shiqiang YANG. " Understanding the Power of Pull-based P2P Live Streaming and Doing Even Better". ACM SIGCOMM 2007, Poster Session, August 2007. (ACM SIGCOMM'07)

• Meng ZHANG, Chunxiao CHEN, Yongqiang XIONG, Qian ZHANG, and Shiqiang YANG. " Optimizing the Throughput of Data-Driven based Streaming in Heterogeneous Overlay Network". In the Proceedings of ACM Multimedia Modeling 2007, Vol. 4351, January 2007. (ACM MMM'07)

• Meng ZHANG, Yongqiang XIONG, Qian ZHANG, and Shiqiang YANG. " On the Optimal Scheduling for Media Streaming in Data-driven Overlay Networks". In the Proceedings of IEEE GLOBECOM 2006, November 2006. (IEEE GLOBECOM'06) (Presetation)
  This paper is one of the Best Student Paper Award Finalists of Globecom'06 (17 finalists among 1020 papers, top 2%) (certificate)
  

• Meng ZHANG, Jian-Guang LUO, Li ZHAO, and Shiqiang YANG. " A Peer-to-Peer Network for Live Media Streaming - Using a Push-Pull Approach". In the Proceedings of ACM Multimedia 2005, short paper, November 2005. (ACM Multimedia'05)

• Meng ZHANG, Li ZHAO, Yun TANG, Jian-Guang LUO, and Shiqiang YANG. " Large-Scale Live Media Streaming over Peer-to-Peer Networks through Global Internet". In the Proceedings of the first ACM International Workshop on Advances in Peer-to-Peer Multimedia Streaming, in conjunction with ACM Multimedia 2005, November 2005. (P2PMMS'05) (Presentation)

• Meng ZHANG, Yun TANG, Li ZHAO, Jian-Guang LUO, and Shiqiang YANG. " A Multi-Sender Based Peer-to-Peer Multicast System for Video Streaming". In the Proceedings of IEEE International Conference on Multimedia & Expo 2005, July 2005. (IEEE ICME'05)

Projects                                                                                                  

GridMedia project was launched in March 2004 and its motivation was to deliver high-quality live video content to millions of users through global Internet from any PC. In May 2004, we released the first version of GridMedia and successfully provided live conference broadcasting on CERNET (China Education & Research Network). In January 2005, GridMedia was adopted by CCTV (the largest TV station in China) to broadcast Gala Evening for Spring Festival (Chinese New Year) and we then released the second version of GridMeida. In the Gala Evening (Feb. 8th 2005), over 500,000 users were attracted all over world, and the peak simultaneous users achieved 15,239, which was a record of concurrent online number supported by one streaming server with high bit rate (300kbps) till then. In Jan. 28th 2006, GridMedia again broadcast the Gala Evening of Spring Festival for CCTV. And this time, the maximum concurrent online number in the CCTV1 channel was over 224,000 (an incredible concurrent number that became a new record then) from more than 60 countries (about 79% from Mainland China) and the average online duration of users was about 3300 sec (nearly an hour). It was achieved by only one server with about 200Mbps outgoing bandwidth consumed.

I am the key designer and developer of GridMedia kernel. The design details of GridMedia can be seen from my papers at ACM Multimedia'05 (download) and its workshop P2PMMS'05 (download), moreover, there is also a brief introduction to GridMedia mechanism below. Collaborators: Li ZHAO, Jianguang LUO, Wenjie FU, Yifei ZHANG, Ji LUO, Yuzhe JIN

GridMedia homepage: http://www.gridmedia.com.cn
Try to use GridMedia:
Downloading client software: ( local download) (download from cctv)
Or watching on web by ActiveX plugin: ( http://www.cctv.com/p2p/index.htm)

Since some researchers and engineers are interested in GridMedia protocol, I give a brief introduction of GridMedia protocol here. GridMedia is a very successful project not only because it has the ability to support incredible concurrent users by one server but also due to its very low delay compared to other deployed p2p streaming systems. The protocol in GridMedia is "push-pull". In pull mode, each node has a window which contains all the current packets interested by that node. And each node will periodically send buffer map to its neighbors to tell the neighbors what packets it has now. The buffer map of a node is a bit map where every bit represents whether a corresponding packet is in its own buffer, that is, 1 represents it is in and 0 represents not. Therefore, once a node receives a buffer map form a neighbor it will knows what packets that neighbor has. Then every node can request its missing packets from the neighbors who have them. For push, we divide the stream into multiple sub streams. Each sub stream is composed of the packets whose sequence number modulo a constant M equals to the same number. If one packet in a sub stream was pulled from a neighbor, then the following packets in that sub stream will tend to be pushed or relayed directly from the neighbor in the future. The Pushing Packet Map (PPMAP) is to tell each neighbor which sub stream should be pushed directly in the next period. When a node just joins in the overlay, it will use pull mode to requests its desired packets and then all the packets will directly pushed to it. When a main supplying neighbor of a node quits or fails, the node will also switch to pull mode to do quick recovery. So it is obvious that the paths of every pulled packet forms a tree in the overlay (it is indeed a routing process even though no proactive routing protocol is used) and in the push mode all the sub stream will be pushed through that tree. We also call this protocol passive overlay multicast routing. We strongly believe that complicated protocols may not work well in real deployed systems, accordingly, the protocol we used is very simple but efficient. In our previous work, we have evaluated our protocol on PlanetLab. Recently, we realize that this mechanism is much more powerful than we expected, and we would like to re-visit this protocol and give more insight to understand it better.

To support delay guaranteed interactive applications and to provide good performance for not only large scale group in one channel but also small scale group in a channel, I developed iGridMedia, which is the extended version of GridMedia. In almost all aspects, this project represents the state-of-the-art of the current real implemented live P2P streaming system. As GridMedia Project, iGridMedia also has perfect scalability and suitable for very large scale user number in one channel. Besides, iGridMedia well balanced the tradeoff between the delay, the quality and server bandwidth cost and is highly configurable. And it has excellent performance with small and mediam size user group in one channel so that a large number of channels with small user group in each one can be supported. Fot a 15-node channel, with 560kbps streaming rate and 1.5 sec guaranteed delay (on every peer, the video packet will be pushed to vlc player exactly 1.5 sec after it’s generated by the capturer), in 70% time the server bandwidth consumed is under 1Mbps and in most time it is under 2Mbps. Under 300-sec online time churn rate, for a 1000-node channel with 560kbps streaming rate and 10-sec guaranteed delay, it at most only consumes around 6Mbps server bandwidth with nearly all nodes 100% quality; Also for a 1000-node channnel, with 5 sec guaranteed delay and 560kbps streaming rate, the server bandwidth cost is only around 8Mbps. iGridMedia is built on P2Framework. Some of its design ideas can be found in the paper to be published at Globecom'08 (paper download).

Now iGridMedia source code is opened including all servers and client code:

igm.source.2008-08-02.repacked.tar.bz2

Please read the file "INSTALL" to build all the code on both win32 and linux. And goto directory "examples" to see some samples for usage

P2Framework is an open source project. It is a highly efficient platform for making distributed system development much easier. With this platform, you can forget many annoying and trivial things in the distributed system development (such as NAT/firewall traversal, udp/tcp protocol switch, etc.).
The main focus on this framework is to ease the P2P connection establishment, data and message transmission. With P2Framework, the developers do not need to care NAT traversal, firewall/proxy problem, UDP reliability and TCP short send/receive problem (etc.) in peer-to-peer environment. For example, peers may behind NAT or uses a http proxy to access Internet. Another example is that the developers may want handle UDP and TCP connections in the same way, such as, one may want to UDP can transmit messages reliably and TCP can transmit data block by block rather than stream. In P2Framework, all kinds of connection establishment and data transmission are encapsulated as almost the same interfaces. You can use the mixed connection in P2Framework to try to establish the best connection you like between peers. Besides, all the network operations are non-block in P2Framework which only runs signle thread. So the developer do not need to use mutex. And P2Framework can be built on both win32 and linux platforms. Till now, some Internet peer-to-peer live and video-on-demand commercial P2P systems in China are built on these framework.
To download p2framework, please go to the site at: http://sourceforge.net/projects/p2framework
or directly download source code here

An updated project of P2Framwork is P2Net and the source code can be found here
http://media.cs.tsinghua.edu.cn/~zhangm/download/p2net_2008_07_18.zip

Honors Awarded                                                                                   

Graduate:

2008	Excellent PhD Thesis of Tsinghua University for the year of 2008
2007	Top Scholarship in Computer Science Department in Tsinghua University
2007	SIGCOMM 2007 Student Travel Grant
2006	Best Student Paper Award Finalist of Globecom'06 (17 finalists among 1020 papers, top 2%) (certificate)
2006	IEEE COMSOC Student Travel Grant Award Winner for Globecom'06 (18.5% winning ratio) (certificate)
2006	Guang Hua Scholarship, Tsinghua University
2005	Hong Kong Medeli Scholarship, Tsinghua University

Undergraduate:

2003	Excellent study scholarship - Rong Hong Scholarship, Tsinghua University
2002	Top scholarship in Dept. of Computer Sci. & Tech. in Tsinghua - TOSHIBA Scholarship, Tsinghua University
2001	Excellent study scholarship - Chinese Academy of Science Scholarship, Tsinghua University

Professional Experiences                                                                      

Visiting:

Sep. 2005 - Mar. 2006	Working at Wireless & Networking Group in Microsoft Research Asia (MSRA) advised by Yongqiang XIONG as a visiting student
Dec. 2006 - Mar. 2007	Working at Department of Computer Science and Engineering in Hong Kong University of Science and Technology (HKUST) advised by Prof. Qian ZHANG as a visiting student

Reviewing for Journals & Conferences:

• Elsevier Computer Networks
• IEEE Communications Magazine
• IEEE Transactions on Multimedia
• IEEE Transactions on Circuits and Systems for Video Technology
• IEEE ICDCS 2008
• IEEE GLOBECOM 2007
• IEEE ICC 2007
• IEEE ICME 2006