Recent advances in quantum information processing like quantum key distribution (QKD) are already in deployment ensuring secure end-to-end communication. This is especially important today, because of the risk posed by quantum computing to current Internet-based encryption technology such as RSA. At the same time there is a multitude of emerging quantum information based technologies with a high promise of revolutionizing their respective areas of application. These include ultra-high-precision distributed sensing with applications to metrology and science discovery (e.g., LIGO), much higher-rate deep space optical communications than possible with conventional systems, and polynomial speedups on search with implications to big data. Most of these applications are enabled by high-rate distributed shared quantum entanglement between pairs and groups of users. The goal of this project is to develop a distributed infrastructure in the form of a quantum network to enable reliable, large scale quantum entanglement distribution. Progress in that direction will catalyze quantum computing advances in the same way the Internet boosted computing to conquer most aspects of contemporary economy and society. The goal of the project is the fully-informed study of the design and operation of quantum networks combining physical-layer device noise models with the ground-up development of higher-layer network protocols. It aspires to bridge the intellectual gap between the quantum information and physics communities who are the ones primarily involved in developing quantum communication protocols, and the networking community who have decades of experience in the design and analysis of practical computer and communication networks. The proposed research will both: (a) inform device needs and specifications pushed down by network application requirements; and (b) help develop network routing and resource allocation protocols optimized for device quality metrics, such as quantum memory coherence times and detector excess noise. The project will culminate in the development of new tools and algorithms for a completely new family of networking protocols for a problem set up and resource constraints that have no immediate classical analogues. 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.