NeTS: Medium: Collaborative Research: Modeling, Design and Emulation of P2P Real-Time Streaming Networks

新兴趋势表明，很大一部分互联网流量将来自实时流媒体应用。然而，考虑到任何内容的受欢迎程度的不可预测性和用户需求的显著波动，提供一个能够保证实时流所需的严格服务质量约束的集中内容分发系统是一项非常困难的任务。因此，本项目研究以点对点（P2P）方式利用终端用户资源进行实时流的建模范例和系统设计。其基本原理是，P2P网络比集中式内容分发系统更容易动态适应不断变化的网络条件和服务需求。本研究采用整体方法，一方面，我们研究点对点流的基本性能限制，并设计分布式算法来实现这些限制。另一方面，我们使用这些算法作为构建块来构建实际协议，并在仿真测试平台上实现和验证。我们汇集了一套丰富的分析工具，从随机过程、优化和控制理论中提取，将它们与现实生活中的视频编码、丢帧和转码问题以及实际实施问题相结合。除了为日益网络化的世界开发可行的视频流媒体创意所带来的技术影响外，我们的项目还通过课程开发、推广和整合弱势群体，为学生和更广泛的社会提供信息和教育。

Emerging trends suggest that a significant share of Internet traffic will be due to real-time streaming applications. However, given the unpredictable nature of popularity of any content and the significant swings seen in user demand, provisioning a centralized content distribution system that can guarantee the strict quality of service constraints needed for real-time streaming is a very difficult task. Therefore, this project studies modeling paradigms and systems design for utilizing end-user resources for real-time streaming in a peer-to-peer (P2P) fashion. The rationale is that P2P networks can dynamically adapt to changing network conditions and service requirements more easily than centralized content distribution systems.This research effort takes a holistic approach in which, on one hand, we study fundamental performance limits of peer-to-peer streaming and design distributed algorithms to achieve these limits. On the other hand, we use these algorithms as building blocks to construct practical protocols that are implemented and validated on an emulation testbed. We bring together a rich set of analytical tools drawn from stochastic processes, optimization and control theory to merge them with real-life multimedia issues of video coding, frame dropping and trans-coding as well as practical implementation issues. Besides the technological impact of developing viable video-streaming ideas for an increasingly networked world, our project also informs and educates both students and the broader society with curriculum development, outreach and integration of under-represented groups.