CIF: Medium: Collaborative Research: Content Delivery over Heterogeneous Networks: Fundamental Limits and Distributed Algorithms

由于内容革命，通信网络的设计模式发生了转变：重点已经从建立连接转移到传递内容。内容分发网络承载了现代互联网的大部分数据，仅视频就占据了近80%，消耗了大量的资源。数据中心的能源成本与中等规模的国家相当。传统的内容分发网络设计涉及集中的资本密集型基础设施。为了实现可扩展的性能，下一代内容分发网络必须利用“边缘云”，即由大量功能强大的终端用户设备（如智能手机、平板电脑和电子阅读器）组成的云。在这个项目中，我们解决了与下一代内容分发网络的分布式特性相关的模型、基本限制以及存储和交付算法的问题。该项目的主要目标是开发一个全面的理论来描述此类网络的基本容量和性能限制，并设计相关的内容存储和分发算法来实现这些限制。内容分发网络产生了绝大多数的互联网流量，我们希望我们的研究结果能够指导下一代这样的网络。特别地，我们探索了在异构网络上支持健壮和高效的分布式存储和内容交付的方法。我们的建议的一个不可或缺的关键方面是将项目的理论和概念方面与实际和现实世界的工程问题紧密联系起来。该方法通过在研究人员所在的每一所大学建立测试平台以及针对提案的每个主要主题（存储、集中交付和点对点交付）来强调。随着多媒体内容消费成为当今在线体验的核心，这项工作的结果有望为无缝的最终用户体验做出贡献，同时释放大量的回程资源，避免可能困扰当今网络基础设施的饱和。

There has been a paradigm shift in the design of communication networks due to the content revolution: the focus has shifted from making a connection to delivering content. Content Distribution Networks carry much of the data of the modern Internet, with video alone occupying nearly 80%, consuming a massive amount of resources. The energy cost of data centers rivals that of medium sized countries. Traditional content distribution network designs have involved centralized capital-intensive infrastructure. For scalable performance, next generation content distribution networks will have to harness the "edge-cloud," consisting of vast numbers of highly capable end user devices such as smart phones, tablets, and e-readers. In this project we address the issues of models, fundamental limits, and storage and delivery algorithms associated with the distributed nature of next generation content distribution networks. The main goal of this project is to develop a comprehensive theory for characterizing the fundamental capacity and performance limits of such networks, and to design the associated content storage and distribution algorithms to achieve these limits. Content distribution networks generate the vast majority of all internet traffic, and we expect our results to guide the next generation of such networks. In particular, we explore ways to support robust and efficient distributed storage and delivery of content over heterogeneous networks. An integral and key aspect of our proposal is to closely tie the theoretical and conceptual aspects of the project with the practical and real-world engineering issues. This approach is highlighted by building testbeds at each of the universities of the investigators as well as specific to each of the main topics (storage, centralized delivery, and peer-to-peer delivery) of the proposal.As multimedia content consumption becomes the centerpiece of today's on-line experience, the results of this work are expected to contribute to a seamless end-user experience, while freeing up significant backhaul resources and avoiding the saturation that would otherwise plague today's network infrastructure.