CIF: Small: Cooperation in networks: a quantitative study

本项目研究分布式网络中的合作，首先通过研究简单的结构来隔离用于全球或本地合作的专用资源，然后直接在一般网络中进行研究。这项工作分为三个重点。第一个推力使用一个全局促进者，该促进者可以访问网络中的所有消息，并可以将这些消息的rate-R描述传输到所有节点。将这种网络的容量限定为R的函数，给出了给定网络中合作的最小成本和最大效益的一阶估计。在第二个重点中，我们将从全球合作模式转向地方合作模式，以了解使用较小的合作者群体可以实现多少合作优势。最后的推力研究了在无线、传感器和有线网络中使用的早期推力中最成功的合作策略的实现和近似；在这里，用于实现合作的速率与其旨在增加的容量共享相同的网络资源。示例网络通过使用在通信设备之间采用合作的策略，在通信系统性能方面展示了巨大的潜在利益。这里的性能改进是通过通信网络可靠传递的信息量的增加来衡量的。通过合作提高速率可以允许更多的用户同时通信，或者允许每个用户在给定网络中以增加的速率进行通信。本项目旨在发展基于合作的通信策略的理论基础，并帮助指导通信协议的设计，在实践中实现合作的好处。

This project addresses the study of cooperation in distributed networks, first through the study of simple structures that isolate dedicated resources for global or local cooperation and then directly in general networks. The work is organized into three thrusts. The first thrust employs a global facilitator that has access to all messages in the network and can transmit a rate-R description of these messages to all nodes. Bounding the capacity of such a network as a function of R gives a first-order estimate of the minimal cost and maximal benefit of cooperation in a given network. In the second thrust, we move from global to local models of cooperation to understand how much of the cooperative advantage can be achieved using smaller groups of cooperators. The final thrust studies the implementation and approximation of the most successful cooperation strategies from the earlier thrusts for use in wireless, sensor, and wired networks; here the rate employed to enable cooperation shares the same network resources as the capacity it aims to increase.Example networks demonstrate large potential benefits in communication system performance through the use of strategies that employ cooperation among the communicating devices. Performance improvement is here measured as an increase in the amount of information that can be reliably delivered through a communication network. Increasing rate through cooperation may allow more users to simultaneous communicate or each user to communicate at an increased rate in a given network. This project aims to develop the theoretical foundations of cooperation-based communication strategies and to help guide the design of communication protocols that realize the benefits of cooperation in practice.