  UMBRELLA is an open, large-scale IoT ecosystem deployed across South
Gloucestershire, UK. It is intended to accelerate innovation across multiple
technology domains. UMBRELLA is built to bridge the gap between existing
specialised testbeds and address holistically real-world technological
challenges in a System-of-Systems (SoS) fashion. UMBRELLA provides open access
to real-world devices and infrastructure, enabling researchers and the industry
to evaluate solutions for Smart Cities, Robotics, Wireless Communications, Edge
Intelligence, and more. Key features include over 200 multi-sensor nodes
installed on public infrastructure, a robotics arena with 20 mobile robots, a
5G network-in-a-box solution, and a unified backend platform for management,
control and secure user access. The heterogeneity of hardware components,
including diverse sensors, communication interfaces, and GPU-enabled edge
devices, coupled with tools like digital twins, allows for comprehensive
experimentation and benchmarking of innovative solutions not viable in lab
environments. This paper provides a comprehensive overview of UMBRELLA's
multi-domain architecture and capabilities, making it an ideal playground for
Internet of Things (IoT) and Industrial IoT (IIoT) innovation. It discusses the
challenges in designing, developing and operating UMBRELLA as an open,
sustainable testbed and shares lessons learned to guide similar future
initiatives. With its unique openness, heterogeneity, realism and tools,
UMBRELLA aims to continue accelerating cutting-edge technology research,
development and translation into real-world progress.
