CIF: Small: Collaborative Research: When Small Changes Have Big Impact: Improving Network Reliability and Security via Low-Rate Coordination

在过去的十年中，出现了各种各样的网络通信系统，几乎影响了我们社会的各个方面。特别是，分布式和多用户应用程序的趋势日益增长，同时人均数据使用量呈指数级增长。为了支持这场数据革命，除了5G等新兴无线技术之外，还需要进一步的技术进步，以增加现有网络基础设施的比特承载能力。尽管最近在网络通信方面取得了进展，如合作和机会通信以及提高网络容量的多址技术，但通信系统的设计仍然主要基于所谓的分离原则，即跨点对点信道的通信独立于周围网络进行。虽然具有简单性的优点，但这种分离原则忽略了可能带来更好性能的方法。该项目寻找通信网络设计的微小变化，这些变化可能对网络的可靠性和安全性产生不成比例的巨大影响。因此，可以以较低的成本获得超越分离的收益。特别是，该项目探索了协调的使用，在设备之间共享少量数据，以便它们共同优化其行为。这种对少量协调的使用打破了分离范例，但只是一点点，因此现有的网络基础设施可以保持基本不变。协调技术在理论、基本限制以及实现它们的实际方法方面都进行了探索。该项目分为三个相互关联的重点。第一个重点是通过由相互信任的节点组成的网络中的低速率协调来提高网络可靠性。这项工作的一个关键方面是边缘去除问题，它构成了低速率协调能力的数学基础，并且与通信网络基本限制研究中的许多重要问题密切相关。第二个重点研究的是包含信道衰落或恶意对手的网络。在这种入侵存在的情况下，协调可以显著地使网络受益？S的工作能力。第三个要点为通信网络中的协调引入了一个新的分而治之的框架，其中节点同意将网络分解为小块，并在每个块中执行简单的编码。这种新的体系结构优于单纯的分离，而不会引入破坏性的复杂性。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The last decade has seen the emergence of a wide variety of networked communication systems, affecting nearly every aspect of our society. In particular, there is a growing trend towards distributed and multiuser applications, simultaneously with an exponential increase in data use per capita. To support this data revolution, further technological advances beyond emerging wireless technologies such as 5G are required to increase the bit-carrying capacity of the existing network infrastructure. Despite recent advances in network communication, such as cooperative and opportunistic communication and multiple access techniques to improve network capacity, the design of communication systems is still mostly based on the so called separation principle, in which communication across point-to-point channels is done independently of the surrounding network. While having the advantage of simplicity, this separation principle ignores approaches that could bring even better performance. This project looks for small changes to the design of communication networks that can have a disproportionately large impact on the network's reliability and security. Thus, the gains from moving beyond separation can be obtained at low cost. In particular, the project explores the use of coordination, in which a small amount of data is shared among devices so that they can jointly optimize their behavior. This use of a small amount of coordination breaks the separation paradigm, but only a little bit, so that the existing networking infrastructure can remain mostly intact. Coordination techniques are explored both in terms of the theoretical, fundamental limits, as well as practical approaches toward achieving them. The project is divided into three interrelated thrusts. The first thrust focuses on improving network reliability via low-rate coordination in networks composed of mutually trustworthy nodes. A key aspect of this work is the edge removal problem, which constitutes the mathematical foundation for the power of low-rate coordination, and is intimately related to many important questions in the study of the fundamental limits of communication networks. The second thrust investigates networks that contain either channel fading or malicious adversaries. In the presence of such intrusions, coordination can significantly benefit the network?s ability to work around them. The third thrust introduces a new divide-and-conquer framework for coordination in communication networks wherein nodes agree upon a network factorization into small blocks and perform simple coding within each block. This new architecture outperforms naive separation without introducing debilitating complexity.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.