Our journal paper “A city-wide experimental testbed for the next generation wireless networks” is published in the journal of Ad Hoc Networks. In this paper, we present a city-wide wireless testbed providing researchers and students with realistic radio environments, standardized experimental configurations, reusable datasets, and advanced computational resources. The testbed contains 5 cognitive radio sites deployed on two campuses of the University of Nebraska-Lincoln and a public street in the city of Lincoln, Nebraska. The testbed is equipped with flagship software-defined radio transceivers, over-the-air and underground antenna arrays, and 20Gbps fronthaul connectivity to cloud facility on campus, and provides remote access to sandbox and live setups of wireless experiments. The development is in collaboration with departments of the university, city of Lincoln, and industrial partners. The goal of this testbed is to improve the accessibility and reproducability of wireless experiments in dynamic spectrum access, 5G/6G, vehicular networks, underground wireless communications, and radio frequency machine learning.