  Location-aware networks will enable new services and applications in fields
such as autonomous driving, smart cities, and the Internet-of-Things. One
promising solution for ubiquitous localization is network localization and
navigation (NLN), where devices form a network that cooperatively localizes
itself, reducing the infrastructure needed for accurate localization. This
paper introduces a real-time NLN system named Peregrine, which combines
distributed NLN algorithms with commercially available ultra-wideband (UWB)
sensing and communication technology. The Peregrine software application, for
the first time, integrates three NLN algorithms to jointly perform the tasks of
localization and network operation in a technology agnostic manner, leveraging
both spatial and temporal cooperation. Peregrine hardware is composed of
low-cost, compact devices that comprise a microprocessor and a commercial UWB
radio. This paper presents the design of the Peregrine system and characterizes
the performance impact of each algorithmic component. Indoor experiments
validate that our approach to realizing NLN is both reliable and scalable, and
maintains sub-meter-level accuracy even in challenging indoor scenarios.
