  Colosseum is an open-access and publicly-available large-scale wireless
testbed for experimental research via virtualized and softwarized waveforms and
protocol stacks on a fully programmable, "white-box" platform. Through 256
state-of-the-art software-defined radios and a massive channel emulator core,
Colosseum can model virtually any scenario, enabling the design, development
and testing of solutions at scale in a variety of deployments and channel
conditions. These Colosseum radio-frequency scenarios are reproduced through
high-fidelity FPGA-based emulation with finite-impulse response filters.
Filters model the taps of desired wireless channels and apply them to the
signals generated by the radio nodes, faithfully mimicking the conditions of
real-world wireless environments. In this paper, we introduce Colosseum as a
testbed that is for the first time open to the research community. We describe
the architecture of Colosseum and its experimentation and emulation
capabilities. We then demonstrate the effectiveness of Colosseum for
experimental research at scale through exemplary use cases including prevailing
wireless technologies (e.g., cellular and Wi-Fi) in spectrum sharing and
unmanned aerial vehicle scenarios. A roadmap for Colosseum future updates
concludes the paper.
