RF Monitoring on Powder

Powder is capable of being used in large-scale repeatable channel measurement studies. In addition to being frequency-agile, the Powder platform has a large number of endpoints, at rooftop height, endpoint (human) height, and co-located with mobile shuttles. These can be reserved for use in a large channel measurement study, and can be repeatedly used to measure the same network in different weather / seasons, interference, and time-of-day conditions. Several studies have been performed and published by the Powder team related to RF activity in the Powder deployment area. Work on characterizing pairwise channel conditions (sounding) has also been conducted across platform resources. These studies highlight the power of Powder as a platform for monitoring and RF conditions in a real world, large scale setting.

Powder has multiple starting points for launching your own monitoring work.

Powder provides an out-of-the box experience for using GNU Radio and UHD toolchains to work with the software defined radios (SDRs) on the platform. Across the X310s on rooftops or B210s in mobile and fixed endpoints, profiles are available to get you up and running quickly. Tutorials on using UHD and GNU Radio tools for conducting path loss measurements help effectively orient you to both the Powder deployment, and the essential use of these tools.

Mobile measurements can be bootstrapped with ease, including responsive GUI environments exported over Powder's out-of-band control network (via commodity cellular). Getting started with mobile resources can be accomplished with just a few clicks.

Signal localization work typically requires accurate clock synchronization across multiple devices. Powder's White Rabbit clock synchronization network locks rooftop radios to a single, centralized, GPS-disciplined clock source, allowing for accurate Time Difference of Arrival (TDoA) techniques to be used. Work utilizing these facilities has been successfully conducted and the setup has been bundled for you to get started with.

Powder has bundled the Shout sounding and measurment framework for you to use across any frequency ranges supported by the platform. This tool allows for taking passive received signal measurements, or doing active, coordinated sounding runs which include transmitters and sequenced events.

The Powder team runs periodic, opportunistic power spectral density scans of the FR1 (10 MHz - 6 GHz) spectrum across all of our rooftop and fixed endpoint devices. These scans take advantage of radios that are not currently allocated by other active experiments. This data can be viewed interactively via the Powder web UI, and is also available for download as a (periodically updated) dataset.

Resources for conducting monitoring on Powder

These resources will get you up and running quickly with monitoring on Powder.
  • GNU Radio over-the-air profile that allows easy selection of rooftop, fixed endpoint, and mobile devices along with single-click option to provision an X11 GUI environment on the compute nodes paired with the software defined radios.
  • Mobile endpoint with GNU Radio profile which provides an instant setup of uhd_fft-based monitoring across all currently-operating campus shuttles.
  • A video showing a walkthrough of the above mobile endpoint profile from instantiation through live experimentation.
  • This write-up describes how to perform localization work on Powder as developed by Powder Co-PI Neal Patwari and his students at the University of Washington at St. Louis.
  • Also from Neal and team is the following write-up that details how to conduct channel impulse response measurements using the Powder platform.
  • The Shout measurement framework with WiMatch channel matching funcationality has been bundled up with an extensive tutorial in this profile.
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