GNU Radio Conference 2022

25 Sept 2022, 08:00 → 30 Sept 2022, 18:30 US/Eastern

Capital Hilton

GRCon22 was a great success with over 250 in-person attendees!  For those who missed it, all of the main talks are available below

GNU Radio YouTube Channel

Or if you want to watch each entire day, you can use the live-stream recordings below:

Monday: Sept 26

Tuesday: Sept 27

Wednesday: Sept 28

Thursday: Sept 29

 

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GNU Radio Conference (GRCon) is the annual conference for the GNU Radio project and community, and has established itself as one of the premier industry events for Software Radio. It is a week-long conference that includes high-quality technical content and valuable networking opportunities. GRCon is a venue that highlights design, implementation, and theory that has been practically applied in a useful way. GRCon attendees come from a large variety of backgrounds, including industry, academia, government, and hobbyists.  With an annual program that has broad appeal, GRCon attracts people new to Software Radio just looking to learn more, experts that want to keep their finger on the pulse & direction of the industry, and seasoned developers ready to show off their latest work.

GRCon22 is the 12th Annual GNU Radio Conference and will be held September 26-30, 2022.

Key Dates

• March 25 - Call for Participation Open for Abstract Submissions
• April 22 - Start of Ticket Sales
• July 17 (Extended) - Call for Participation Abstract Submissions Close
• August 26 - Initial Main Track Schedule Posted
• September 25 - Presenter's Slides Due
• September 26 - Conference Begins 

We invite developers and users from across the GNU Radio Community to present your projects, presentations, papers, posters, and problems at GNU Radio Conference 2022, so start thinking about what great work you would like to present at this year’s conference.  Check out the Call for Participation page for more information, or submit work using the button at the bottom of this page.

Attendance Justification Letter

Do you need help justifying why your manager or supervisor should send you to GRCon this year? Feel free to use this example email.

GRCon22 Registration

GRCon22_COVID_Release.pdf

Sunday, 25 September

17:00 → 20:00 GRCon22 Social: Early Check-In

Penn Social

17:00 Early Check-In

Come check-in early and hang out with us. This is an unofficial "social." No food or drinks provided (officially), but you are welcome to stop by and be social. We could always use the extra help/company.

Monday, 26 September

08:00 → 08:45 Conference Check-in

08:45 → 09:10 Monday Opening

Speaker: Martin Braun (GNU Radio)

09:10 → 10:45 Main Track

09:10 Wireless CTF Announcement

Speaker: Clayton Smith

02_ctf.pdf

09:15 gr-dvbs2rx: An overview of the project state and path forward

Since its creation in 2018, gr-dvbs2rx has evolved into a fully-functional standard-compliant DVB-S2/S2X receiver implementation with SIMD acceleration in various CPU-intensive processing tasks, such as LDPC decoding and PHY signal processing. It is one of the few open-source software-defined receiver implementations for DVB-S2 and certainly one of the most capable and flexible in parametric customizations and SDR compatibility. However, there are still many pending extensions and improvements for the project to support a wider variety of DVB-S2/S2X operation modes and achieve higher throughput with more CPU efficiency and better overall performance. This talk addresses the project's current state, supported operation modes, limitations, and performance expectations. Furthermore, it provides an overview of the CPU utilization by various blocks composing the receiver and discusses the path forward for their optimization and improvement. Lastly, the talk briefly shows example commands for running the receiver and highlights real-world results with real-time reception of the 1 Mbaud DVB-S2 signal broadcast worldwide by the Blockstream Satellite project in the Ku and C bands.

Speaker: Igor Freire

grcon2022_dvbs2rx.pdf

09:30 CyberEther: Portable Native GPU Accelerated Frequency Sink

CyberEther offers a GPU accelerated frequency sink interface (2D Waterfall, Lineplot, Spectrogram). It works natively using modern graphical APIs like Metal, Vulkan, and WebGPU. The internal Digital Signal Processing (DSP) is accelerated whenever possible using parallel computing APIs like CUDA, Metal, and Vulkan. By being modular, CyberEther can adapt to the target device and run with the best-supported combination possible. For example:

• Apple Silicon (Mac/iPad): Metal (Graphical), vDSP (DSP).
• Web Browser: WebGPU (Graphical), FFTW (DSP).
• Raspberry Pi: Vulkan (Graphical), VkFFT (DSP).
• Linux Desktop: Vulkan (Graphical), CUDA (DSP).

The CyberEther interface is also portable and written in modern C++20. A developer can implement it in their application with minimal changes. The number of core dependencies is minimal. Acceleration and graphical modules are loaded only if all dependencies are available at compilation time, avoiding dependency hell.

This talk aims to demonstrate CyberEther working as a GNU Radio out-of-tree module and explain how the internal DSP works. The development process and heterogeneous computing optimization tips and tricks will be shared along the way. The development roadmap including further GNU Radio integration will also be discussed.

Speaker: Luigi Cruz (SETI Institute)

GNU Radio Conference 2022 - CyberEther.pdf

10:00 GPIOs on USRPs: The Definitive Guide

When thinking of I/Os on USRPs, GPIOs are sometimes forgotten among all the RF and high-speed digital connections. However, GPIOs on USRPs are very useful, and UHD provides some powerful APIs to do all sorts of things with these pins.

In this talk, we'll summarize all the features that UHD and USRPs provide on the GPIO lines, including new features that came with the release of the X410. We will go over how to use GPIOs and how to not use them, what they can be used for, how to connect them, and how to integrate them into your application. We will also go into the differences between the different USRPs.

In short, this talk should provide all you need to know for using GPIOs on USRPs!

Speaker: Martin Braun (GNU Radio)

GPIOs on USRPs.pdf

10:30 Debugging GNU Radio Blocks

One of the challenges getting started in developing GNU Radio blocks is sometimes figuring out what went wrong. We will step through how to troubleshoot some of the common situations that arise by exploring the tools available for debugging. In addition to the built-in logging mechanisms, by using Visual Studio Code, we will set up source level debugging and demonstrate the ins and outs of hitting breakpoints in a running flowgraph (and the core GNU Radio code as well).

Speaker: Josh Morman

Debugging GNU Radio Flowgraphs.pptx

10:45 → 11:00 AM Break

11:00 → 12:00 Main Track

11:00 Haystack GSI: An Open Source Satellite Ground Station Interface

Spacecraft in Low Earth Orbit (LEO) typically have communications windows lasting between 5 and 15 minutes. With limited datarates and significant amounts of information to be synced, many satellite missions cannot afford the time it takes for an operator to manually send commands -- especially if human error comes into play. Large communications companies and deep space operations have automated systems to communicate with their spacecraft, but there exist no freely-available software implementations that are compatible with smaller-scale missions, who often end up inputting and uploading commands individually. Haystack GSI, inspired by MIT Haystack Observatory’s AERO/VISTA CubeSat project, aims to change that by developing a modular open-source software solution with a GNURadio OOT package at its core. It abstracts out signal processing and data “plumbing,” utilizing GNURadio Companion as a convenient user interface for operators to configure ground station hardware, direct the outflow of downlinked packets, and schedule commands well ahead of time. Here, we present our progress in development of the Haystack GSI platform and what we plan to work on next.

Speakers: Maximilian Riccioli (University of Texas at Austin), Michael Gutierrez (California Institute of Technology)

Haystack GSI GRCon 2022.pdf

11:30 GNU Radio On-The-Go - How to build GNU Radio Apps for Android

Using GNU Radio on Android platforms has not always been straightforward. First developments started in 2015 when Tom Rondeau presented a paper at GRCON2015 running GNURadio on android. In 2020 Bastian Bloessl continued this work by providing a Docker image that supports building Android applications for GNU Radio 3.8 using some popular hardware frontends as well as adding other functionality.

This presentation shows how we continued this work by adding support for the latest version of GNU Radio (3.10), support for gr-iio, gr-qtgui, and other OOTs in order to port our Scopy application to Android and have it running on an Android tablet with the ADALM2000 using a USB-OTG connection to the device. In the end the audience will learn what it takes to build GNURadio apps for android using Qt. Two demos will also be presented – Scopy on Android and a how to build your own simple FM Radio Android application with Gnuradio and ADALM-PLUTO.

Speaker: Adrian Suciu (Analog Devices Inc.)

Adrian Suciu - SDR on the go - How to build android apps with gnuradio.pptx

scopy-android-setup-example.png

12:00 → 17:00 Expo Hall

Sponsors

12:00 → 13:00 Lunch

13:00 → 17:00 Capture the Flag (CTF)

Capture the flag (CTF) is a competition where contestants earn points by finding secret messages ("flags") hidden in radio signals. Challenge yourself and improve your GNU Radio skills!

GRCon22 CTF

13:00 → 14:30 Main Track

13:00 Open-Source Large Scale Radio Frequency Machine Learning Datasets, Toolkit, and Models

In this RF Machine Learning talk, we introduce the Sig53 dataset, the open-source TorchSig toolkit, and competitive baselines for the task of signal classification using the newly introduced dataset. The Sig53 dataset is a narrowband signals dataset consisting of 5 million synthetically generated samples from 53 different signal classes and expertly chosen impairments meant to accelerate research in the task of signal classification. TorchSig is an open-source signal processing machine learning toolkit with the ability to generate the Sig53 dataset, apply over 50 domain-tailored data augmentations/transformations, interface with neural networks through an image-domain inspired model API, and provide numerous data processing utilities meant to accelerate research in the broad space of RF machine learning. We also share competitive baseline performances of convolutional neural networks and transformer-based architectures on the task of narrowband signal classification using the Sig53 dastaset.

Speaker: Mr Luke Boegner (Peraton Labs)

OpenSourceLargeScaleRFML_20220926.pdf

Paper - LargeScaleRadioFrequencySignalClassification.pdf

13:30 Improved Messaging using Modern PMTs

GNURadio uses Polymorphic Types (PMTs) for asynchronous messaging and data tagging. The current API can be error prone and difficult to use. A new PMT interface is being written using modern C++ and Google Flatbuffers. This new API allows for more intuitive use, better error checking, and better performance.

The presentation will provide performance comparisons with the current API and detail examples of how to use the new PMTs. It will also discuss the path forward to integrate the new PMTs into a mainline release of GNURadio so that developers can start using them in their blocks and flowgraphs.

Speaker: John Sallay

GrCon22 - Pmt.pdf

13:45 Kuiper Linux Distribution - simplify hardware prototyping with GNU Radio

Traditionally, adding hardware interaction to a GNU Radio or Python program, has been challenging. Libraries, drivers, device tree overlays, and GNURadio modules must all be configured properly and tested. Often times, the Linux kernel would need to be rebuilt with the desired drivers enabled. While this is not difficult for an engineer that is familiar with the process, it can still be a daunting task even when everything goes right. However, a recent open source offering from Analog Devices, Kuiper Linux, simplifies much of this. In this presentation we will show how to quickly use GNU Radio and hardware from Analog Devices to build your own 500 MHz FMCW radar.

The Kuiper Linux Distribution is based on Raspbian and is created with ease of use in mind. It incorporates prebuild Linux device drivers for hundreds of Analog Devices components. It supports multiple Circuit Note and Eval boards with RPi HEAD, Arduino, PMOD and FMC connectors. And it allows rapid prototyping complete Converter, RF, Sensor and Control Systems with commercially of the shelf low cost HW.

It preloads a number of important applications, software libraries, and utilities including:
GnuRadio Companion, IIO Oscilloscope (basic GUI for debugging IIO devices), Libiio, pyadi-iio (Python abstraction layer for IIO devices), and many more

While Rasbpian targets Raspberry Pi platform boards, ADI Kuiper Linux supports several other platforms in addition to the Raspberry Pi. These include:
Arduino form factor ARM based FPGA platforms such as Intel/TerASIC DE10-Nano or Xilinx/Digilent Cora Z7
Most popular FMC FPGA carriers from Xilinx and Intel with ARM/ARM64 support: Zynq7000 (Zed board, ZC706, ZC702), MPSoC (ZCU102), Versal (VCK190),
SoC FPGA (A10Soc, A5Soc)

The presentation concludes with a step by step example on how to write the distribution onto an SD Card and customize it for your platform. Then we add a devicetree overlay for a ramping frequency synthesizer wired to the Raspberry Pi, and control that with the GRC flowgraph. Finally, we’ll add in the ADALM-PLUTO, transmit a 500MHz FMCW radar chirp, and plot the radar return in GNU Radio.

Speaker: Michael Hennerich (Analog Devices GmbH)

GRCON 2022 hennerich kraft.pdf

14:15 Sponsor Talk: Elbit Systems

Speaker: Alex Kozlov

13:00 → 15:00 Workshop

13:00 Introduction to Signal Processing

This course is an introduction and survey of signal processing for beginner and intermediate levels. The course will introduce basic math concepts fundamental to and applications of signal processing. The course will explore properties of signals and systems including spectral estimation, detection and information theory.

Speaker: Wylie Standage-Beier

14:30 → 15:00 Lightning Talk Block

15:00 → 15:20 PM Break

15:20 → 17:05 Main Track

15:20 gr-enocean, an OOT for industrial IoT

Enoncean is an IoT protocol used in industrial IoT devices. This talk will cover the process of developing an OOT module to process the signals from a few representative devices. The signal is a packet based signal. The work is currently in progress but will be completed before GRCon. The plan is to release the OOT Module at GRCon. GNU Radio 3.10 will be used for the effort.

Speaker: Mr Toby Flynn (Red Wire Technologies)

Gr-enocean_ano_oot_for_a_commercial_IOT_Protocol.pdf

15:50 Demonstration of GNU Radio High Data Rate QPSK Modem at 15.0 Mbps Real-time with Multi-Core General Purpose Processor (GRCON 2022)

This paper presents a GNU Radio Modulator/Demodulator (Modem) design and an associated test activity that demonstrates a GNU Radio modem can operate at 15.0 Mbps Real‑Time with Quadrature Phase Shift Keying (QPSK), with GNU Radio version 3.10, and with a multi-core (8-core) General Purpose Processor (GPP) inside a relatively low cost Personal Computer (PC). The Modem demodulator design achieves the high date rate with a single GNU Radio flowgraph and without a Field Programmable Gate Array (FPGA) or Graphics Processor Unit (GPU). Specifically, the Modem demodulator design achieves the high data rate by breaking the incoming I/Q sample stream from a LimeSDR‑mini into three “chunk” streams. Each chunk stream then flows to a separate Symbol Synchronizer (symbol synchronization) and Costas Loop (carrier synchronization) chain and each chain uses a separate GPP core. The GNU Radio Modem demodulator then “stitches” the original transmitted single stream back together by only using the frame Acquisition Synchronization Marker (ASM) and the known frame length of each frame.

Speaker: Mr David Miller

GNU Radio HDR Real-Time QPSK 15 Mbps (Camera Ready Submitted 09-19-22).pdf

Presentation Charts - GNU Radio Conference 2022 (David Miller - HDR 15 Mbps Real-Time Modem - Camera Ready).pdf

16:05 Open-Source Software Radio Platform for Enabling O-RAN Research, Prototyping, and Testing

The Open Radio Access Network (O-RAN) within 5G provides interoperability and standardization of RAN elements for hardware and open source software elements from different vendors. O-RAN is, unlike legacy cellular networks, open. It facilitates the integration of software largely developed on Linux platforms and hardware not exclusively developed/chosen by the big players in the cellular network industry. We are developing Open AI Cellular, https://github.com/openaicellular, to enable O-RAN research, rapid prototyping, development, and testing. We leverage srsRAN for the 5G RAN software as well as the specifications and software provided by the O-RAN Alliance and O-RAN Software Community, respectively, for implementing the open data and control interfaces between the RAN and the near real-time RAN intelligent controller, among others. The code that we write for RAN monitoring or control (xApps), testing scripts, and so forth falls under the GPLv3 or MIT/X11 license. We use GNU Radio for emulating multiple UEs for AI scheduling projects, among others, and plan to use it for further development, prototyping, and testing in collaboration with the GNU Radio community. The software is currently compatible with Universal Software Radio Peripherals (USRPs). We offer radio hardware emulation for those who do not have access to USRPs and for comparing results with SDR hardware-in-the-loop and over-the-air experiments. This talk will briefly provide the necessary background on O-RAN and its advantages for the wireless research and development community, then present the Open AI Cellular software platform, code repositories, projects, sample experiments, and opportunities for collaboration with the GNU Radio and open-source software radio communities.

https://github.com/openaicellular/oaic

Speakers: Vuk Marojevic (Mississippi State University), Prof. Vijay Shah (George Mason University)

GRCon22.pptx

Tuesday, 27 September

08:00 → 08:50 Conference Check-in

08:50 → 09:00 Tuesday Opening

09:00 → 10:00 Main Track

09:00 GNU Radio and SETI

In this talk I will give an overview of the SETI Institute, including our broad collaboration with GNU Radio, and opportunities for you to get involved.

Speaker: Dr Steve Croft (UC Berkeley / SETI Institute)

croft_grcon22.pdf

09:30 National Instruments: Updates from the world of USRPs

In this presentation we talk about all the recent updates to the USRP product line, UHD, and RFNoC. We will give some examples of how our most recent features and products can enable you to build SDR applications in all sorts of domains and conquer the world of RF signals!

Speaker: Martin Braun (GNU Radio)

NI Sponsor Talk.pdf

10:00 → 10:45 Keynote: Tuesday Keynote

10:00 Keynote: Dr. Stefanie Tompkins, Director, DARPA

Dr. Stefanie Tompkins is the director of the Defense Advanced Research Projects Agency (DARPA). Prior to this assignment, she was the vice president for research and technology transfer at Colorado School of Mines.

Tompkins has spent much of her professional life leading scientists and engineers in developing new technology capabilities. She began her industry career as a senior scientist and later assistant vice-president and line manager at Science Applications International Corporation, where she spent 10 years conducting and managing research projects in planetary mapping, geology, and imaging spectroscopy. As a program manager in DARPA’s Strategic Technology Office, she created and managed programs in ubiquitous GPS-free navigation as well as in optical component manufacturing. Tompkins has also served as the deputy director of DARPA’s Strategic Technology Office, director of DARPA’s Defense Sciences Office – the agency’s most exploratory office in identifying and accelerating breakthrough technologies for national security – as well as the acting DARPA deputy director.

Tompkins received a Bachelor of Arts degree in geology and geophysics from Princeton University and Master of Science and Doctor of Philosophy degrees in geology from Brown University. She has also served as a military intelligence officer in the U.S. Army.

Speaker: Dr Stefanie Tompkins (DARPA)

10:45 → 11:00 AM Break

10:45 → 17:00 Capture the Flag (CTF)

Capture the flag (CTF) is a competition where contestants earn points by finding secret messages ("flags") hidden in radio signals. Challenge yourself and improve your GNU Radio skills!

GRCon22 CTF

10:45 → 17:00 Expo Hall

Sponsors

11:00 → 11:45 Project Talk

11:00 GNU Radio Project Update

Speaker: Derek Kozel (GNU Radio)

12:00 → 13:00 Lunch

13:00 → 14:45 Main Track

13:00 Vital Sign Sensing in GNU Radio

Vital sign monitoring using radar technologies is a novel area of research fueled by demand for contactless and continuous health monitoring devices.
Many kinds of radar and signal processing techniques are being explored for this purpose, but success has been limited, especially when using low-cost, low-effort, and open-source techniques.
We developed an approach to monitor heart and respiratory rate using GNU Radio and a commercial-off-the-shelf (COTS) software-defined radio (SDR).
SDRs provide an efficient and affordable mechanism to rapidly prototype and validate a variety of radar and signal processing systems.
To demonstrate the viability of our approach, we use an Ettus X310 to implement a Doppler-only, bi-static radar system that transmits a continuous-wave (CW) tone at a center frequency of $4$ GHz.
We use GNU Radio signal processing blocks to extract the heart and respiratory rate of a subject in the radar's field of view and compare the estimates to a traditional heart rate monitor and respiratory rate counter.
In several experimental trials, we demonstrate that the proposed technique successfully extracts the respiration rate and estimates the heart rate to within $\pm$ 5 BPM of a traditional heart rate monitor.

Speaker: Isabella Lenz

grcon_vitals_2022.pdf

GRCon_VitalSign_PesentationSlides_Lenz_9_22.pdf

GRCon_VitalSign_PesentationSlides_Lenz_9_22.pptx

13:30 GNU Radio and CEDR: Runtime Scheduling to Heterogeneous Accelerators

Accelerators in GNU Radio have been previously limited to requiring the selection of an accelerator tor framework/block at design time. In this talk and associated paper, we present a preliminary investigation into supporting two new capabilities with GNU Radio: first, we illustrate the ability to execute GNU Radio blocks across a variety of heterogeneous accelerators (FPGA and GPU). Second, we demonstrate that we are able to dynamically schedule these blocks across our pool of accelerators using easily-customizable scheduling policies. We do this via a combination of out-of-tree modules and by embedding GNU Radio itself as an application in a heterogeneous runtime called CEDR (Mack et al., 2022). The CEDR ecosystem provides a productive environment for researching the combined challenges of application design, systems software, and hardware prototyping for heterogeneous systems, and namely, it provides a flexible intelligent scheduling (IS) interface by which the user can easily adjust or prioritize how tasks are dispatched at runtime to the various accelerators present on a given system. The IS integrates a variety of runtime schedulers that optimize for metrics such as application performance and minimum scheduling algorithm overheads. The IS in tandem with CEDR improves the performance of applications through dynamic scheduling by efficiently utilizing the resources at runtime.

We demonstrate GNU Radio running on heterogeneous hardware using CEDR across both Xilinx Zynq Ultrascale+ ZCU102 and Nvidia Jetson AGX Xavier systems. We choose three applications that can leverage FFT acceleration: we implement Pulse Doppler radar in GNU Radio, deploy in CEDR and execute it along with non-GNU Radio-based WiFi-TX and Synthetic Aperture Radar applications. We find that, when GNU Radio shares the system with other unrelated applications, our integrated IS dispatches FFT tasks to the accelerator on both the FPGA and GPU platforms along with the CPU cores fairly without compromising target throughput for each application. In summary, we show that running the GNU Radio runtime and applications inside/with CEDR enables better scheduling options and easier accelerator access by eliminating the need for users to partition their workloads at design time. We believe this is a stepping stone in broadening GNU Radio’s support for heterogeneous execution and enabling it to hook more flexibly into a variety of scheduling heuristics.

https://github.com/UA-RCL/CEDR
https://ua-rcl.github.io/CEDR/

Speakers: Joshua Mack (University of Arizona), Serhan Gener, Jacob Holtom (Arizona State University)

CEDR Homepage

CEDR Public Sources - GRCon22 Branch

gr-cedr OOT module

grcon_cedr_2022.pdf

Presentation Slides (pdf)

14:00 Open-Source Antenna Pattern Measurement System: SDR-based Student Research and Development

Weber State University (WSU) has developed an ‘open-source’ antenna-pattern measurement system physically comprised of software-defined radios (SDRs) and 3-D printed hardware. An Arduino microcontroller and low-cost stepper motors make up the position control system. The present WSU ‘open-source’ prototype integrates Python, GNU Radio Companion, and Linux on a single laptop PC. GNU Radio Companion software controls the RF link between the source (Tx) and the antenna-under-test (AUT). AUT position is controlled via Python commands sent to the GRBL-configured Arduino. The system is portable and used for education- and industry-outreach.
The Utah NASA Space Grant Consortium has generously supported engineering students on the program. Multiple student projects have investigated methods to improve measurement fidelity in non-optimal environments. For example, excellent agreement between measured and simulated radiation patterns has been obtained using coherent AM detection.
The following paper summarizes the development of the current system and presents results from student research. In addition, efforts are underway to improve the mechanical design, post-processing capabilities, and software-version compatibility. Enhanced post-processing (e.g. 3-D radiation pattern plot) is one improvement discussed in the paper.

Speaker: Mr Matthew Finger (Weber State University)

GNU Radio Slides WSU.pptx.pdf

GRCon22_abstract_WSU.pdf

14:15 FISSURE: The RF Framework for Everyone

FISSURE is an open-source RF and reverse engineering framework built around GNU Radio. It is designed for all skill levels with hooks for signal detection and classification, protocol discovery, attack execution, IQ manipulation, vulnerability analysis, automation, and AI/ML. The framework supports the rapid integration of out-of-tree modules, flow graphs, radios, protocols, signal data, scripts, reference material, and third-party tools. FISSURE is a workflow enabler that keeps software in one location and allows teams to effortlessly get up to speed while sharing the same proven baseline configuration for specific Linux distributions.

The framework and tools included with FISSURE are designed to detect the presence of RF energy, understand the characteristics of a signal, collect and analyze samples, develop transmit and/or injection techniques, and craft custom payloads or messages. GNU Radio flow graphs are included as standalone solutions or manipulated before or during runtime for the purposes of signal detection, demodulation, protocol discovery, live inspection, IQ recording and playback, single-stage attacks, multi-stage attacks, fuzzing, and replaying online signal archive playlists.

The friendly Python codebase and user interface allows beginners to quickly learn about popular tools and techniques involving RF and reverse engineering. Educators in cybersecurity and engineering can take advantage of the built-in material or utilize the framework to demonstrate their own real-world applications. Developers and researchers can use FISSURE for their daily tasks or to expose their cutting-edge solutions to a wider audience. As awareness and usage of FISSURE grows in the community, so will the extent of its capabilities and the breadth of the technology it encompasses.

The major components for FISSURE are written in Python/PyQt and communicate over an IP network to a central hub using ZeroMQ. Each component has a direct connection to the hub but can also have an unlimited number of one-to-many connections to broadcast status messages to other components. Any number of custom components can be added to the framework as long as the inputs/outputs are clearly defined in YAML and adhere to a simple message schema that allows for input sanitization and error handling. The highlights for the components are as follows:

• The Central Hub receives commands from the User Dashboard to distribute to other components, manages automation and editing of the main library – which contains RF protocol information, script and flow graph mappings, and observation data.
• The Target Signal Identification (TSI) component runs four subcomponents: a detector, a signal conditioner, a feature extractor, and a classifier. The purpose of the TSI component is to detect signals of interest, isolate and condition signals for detailed analysis, extract signal characteristics for protocol and/or emitter classification, and apply user-specified AI/ML classification techniques.
• The Protocol Discovery component is responsible for identifying and reversing RF protocols to help extract meaningful data from unknown signals. It is designed to: accept signal of interest information, iterate flow graphs to perform recursive demodulation techniques, deduce protocol methods, assign confidence levels, analyze a bitstream, calculate CRC polynomials, and create custom Wireshark dissectors.
• The Flow Graph/Script Executor component runs flow graphs or Python scripts to perform single-stage attacks, multi-stage attacks, fuzzing attacks, IQ recording and playback, live signal inspection/analysis, and transmit playlists of signal data constructed with files downloaded from an online archive.
• The User Dashboard is the means for the operator to configure FISSURE and communicate with and view information from the other components. It offers several other features that do not require their own dedicated component including:
• A packet crafter for protocols found the FISSURE library. It includes Scapy integration for transmitting different types of 802.11 packets while in monitor mode.
• Library utilities for browsing; searching; uploading images; adding/removing modulation types, packet types, signals of interest, statistics, demodulation flow graphs, and attacks.
• Menu items for launching standalone GNU Radio flow graphs.
• Third-party and online tools as menu items organized by protocol or application.
• Lessons and tutorials for interacting with various RF protocols.
• Help pages for operation and development, protocol reference material, calculators, and hardware instructions.
  • Buttons for: assigning RF-enabled hardware to individual components (USRP B205mini, B210, X300 series; HackRF; bladeRF; LimeSDR; 802.11x Adapters; RTL2832U; Open Sniffer); probing the hardware for diagnostics; and automatically acquiring IP address, daughterboard, and serial number information.

Speaker: Mr Christopher Poore (AIS)

FISSURE_Paper_Poore_GRCon22.pdf

FISSURE_Poore_GRCon22.pdf

13:00 → 16:00 Workshop

13:00 RFNoC Tutorial

Speaker: Mr Neel Pandeya (Ettus Research (NI))

13:00 → 15:00 Workshop

14:45 → 15:00 Lightning Talk Block

15:00 → 15:20 PM Break

15:20 → 18:00 Breakout Session

15:20 Breakout: Documentation

Discuss the current state and future of GNU Radio documentation.

Speaker: Dr Marc Lichtman

15:20 Breakout: New To GR and/or GRCon

Speaker: Samantha Palazzolo

15:20 Breakout: Visualization

The QT GUI Widgets in GNU Radio have been identified as needing a serious refresh. With so many great open source visualization libraries available, and stunning GUIs in other SDR applications - what is the best path forward for GNU Radio's officially supported GUI widgets?

Speaker: Luigi Cruz

16:20 Breakout: GR and FPGA

There have been some great examples of GNU Radio well-integrated with FPGA based platforms for signal processing, such as RFNoC for Ettus radios, or Amalthea as an experimental SDR platform. However, there is no standard approach for coming to such a solution, and these solutions are not portable.

How can GNU Radio better integrate and co-exist with more generic hardware including RFSoC, open source toolchains?

How can the common pieces of FPGA integration with GNU Radio (ingress/egress, FPGA mapped peripherals, cores and IP blocks, etc.) - what toolkits are needed across which hardware toolchains?

What open source tools could be utilized to drive the workflow, such as LiteX?

How can GRC be used as a general purpose graphical workflow representation?

Speaker: Josh Morman

16:20 Breakout: GRC

Deep dive into the new developments of GRC with QT, and share feedback for what GRC should look like / entail in the future

Speakers: Håkon Vågsether, Seth Hitefield

16:20 Breakout: SigMF

Speaker: Dr Marc Lichtman

17:20 Breakout: Women@GRCon

Time to meet up and chat. May very well involve into a group dinner. All are welcome.

Speaker: Samantha Palazzolo

Wednesday, 28 September

08:00 → 08:45 Conference Check-in

08:45 → 09:00 Wednesday Opening

09:00 → 09:45 Keynote: Wednesday Keynote

09:00 Keynote: Satellite Constellations and Radio Astronomy

Planning and construction of non-geostationary satellite constellations providing communications/data has exploded in the past several years. The use of spectrum by these systems is constrained by international treaty and domestic agencies, with attempts to coordinate existing and future users at both centimeter and millimeter radio wavelengths underway. Radio astronomy is a key activity supported by spectrum regulations, and the potential impacts of ngso constellations on our single-antenna and interferometers are a significant concern to the scientific community. To address these issues, NRAO has embarked on a series of test observations with SpaceX involving their early satellite system, the Green Bank Telescope and the Jansky Very Large Array. In this talk I will review the radio astronomy concerns about satellite communications, and present the initial results from our testing. Future initiatives including spectrum sharing, and spatial/frequency coordination of the operations of the astronomy and satellite systems, will be explored.

Speaker: Dr Tony Beasley (NRAO)

09:45 → 10:45 Project Talk

10:45 → 11:00 AM Break

10:45 → 17:00 Capture the Flag (CTF)

Capture the flag (CTF) is a competition where contestants earn points by finding secret messages ("flags") hidden in radio signals. Challenge yourself and improve your GNU Radio skills!

GRCon22 CTF

10:45 → 17:00 Expo Hall

Sponsors

11:00 → 11:45 Main Track

11:00 The State of GRC Qt

The GRC Qt port is approaching feature parity with the GTK version. The Qt version comes with a few changes, some are contained under the hood while others are more visible. It also comes with the opportunity to implement some new features and useability improvements. This talk will give an overview of the current state of the port, with a brief look into the code structure.

Speaker: Håkon Vågsether

The State of GRC Qt.pdf

11:30 Sponsor Talk: Analog Devices

11:45 → 12:00 Lightning Talk Block

12:00 → 13:00 Lunch

13:00 → 14:45 Main Track

13:00 Reverse Engineering the Positive Train Control (PTC) 220 MHz Wireless Protocol

Positive Train Control (PTC) is a collection of standards and technologies that attempts to prevent train collisions and derailments by automating certain safety functions aboard locomotives. The communications layer of one widely fielded PTC implementation uses proprietary wireless protocols operating at 220 MHz. Each locomotive has a PTC radio, and there are also stationary radios at certain points along the tracks and in central office locations.

As an independent vulnerability R&D project at Shift5, we purchased and studied several decommissioned 220 MHz PTC radios available on the open market. Our research is ongoing, but we will present the reverse engineering work that was required to fully decode the physical (PHY) layer of the radio traffic. This included open source research, signal analysis, and software/hardware reverse engineering.

The protocol utilizes a robust phase-shift keying (PSK) signal with non-standard inteleavers, multiple forward error correction (FEC) modes, and custom CRCs. We ultimately wrote a complete C++ library and several custom GNURadio signal processing blocks to implement the physical layer of the wireless protocol. We are able to demodulate/decode packets from the PTC radios as well as transmit our own packets that are correctly received by the radio. We will demonstrate both receive and transmit capabilities during the talk and release a fully functional out-of-tree module and flowgraph for the receive chain.

Speaker: David Twitchell

13:30 Implementing and evaluating TDOA techniques on SDRs: Lessons learned from the field

This presentation explores the challenges of geolocating radio frequency transmitters in real-world environments using software-defined radios (SDR). This research aims to better understand this problem in pursuit of a solution that would be signal agnostic and operate throughout commonly used VHF and UHF bands from 30-3000MHz. With this broad requirement in mind, a time difference of arrival (TDOA) technique was implemented on Ettus X310 USRPs to explore this space. This presentation highlights many common challenges when implementing TDOA in real-world environments and provides potential solutions. These include time synchronization of multiple non-collocated X310s, errors due to geometric dilution of precision, errors due to signal bandwidth, and data backhaul concerns. Real examples from three different experimental layouts compare and contrast signals from FM, HDTV, and LTE transmitters in the greater Boston area. Overall, this research aims to show that TDOA techniques can be very effectively implemented on USRP hardware, but there are many challenges due to signal characteristics and environment. By sharing examples of these challenges along with potential solutions, this presentation aims to help future researchers implement their own geolocation techniques with SDRs.

DISTRIBUTION STATEMENT A. Approved for public release. Distribution is unlimited. This material is based upon work supported by the Dept of the Navy under Air Force Contract No. FA8702-15-D-0001. Any opinions, findings, conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the Dept of the Navy.

Speaker: Mr Sage Trudeau (MIT Lincoln Laboratory)

Implementing and evaluating TDOA techniques on SDRs - Lessons learned from the field_Final_approved.pptx

14:00 Libiio 1.0 design and how it will affect GNU Radio

Gr-iio is a module based around the Industrial Input/Output (IIO) framework,
which has been in the upstream Linux kernels since 2011 and is responsible for
handling sensors, converters, integrated transceivers, and other real-world
I/O devices. It provides a hardware abstraction layer with a consistent API
for the user-space applications. The IIO framework supports discrete
components as well as integrated transceivers like the Analog Devices AD9361,
a 2x2 RF Agile Transceiver, found in many SDR products like the ADALM-PLUTO.
The gr-iio module both provides access to generic IIO devices, and also
contains device-specific blocks for certain SDRs.

The Gr-iio blocks, which are available in the official GNU Radio repository
since 2021, are built on top of a software library named libiio, which has
been created with the objective to provide a lean, robust and simple
interface for applications and frameworks that need to interact with IIO
devices. Since its inception in 2014, it gained new features but has never
broken its ABI, which means that applications written around libiio v0.1 will
still work with 2022's v0.34 version. However, the upcoming libiio 1.0 will
introduce a lot of ABI-breaking changes, in order to improve the interface of
the library, and especially to improve its performance.

In this small talk, I will present the important changes in the upcoming
libiio 1.0, as well as the new changes coming to the IIO subsystem of the
Linux kernel, and what it means for gr-iio and GNU Radio.

Speaker: Paul Cercueil (Analog Devices Inc.)

grcon2022.pdf

14:15 Using Allen Telescope Array Data on GNU Radio

The Allen Telescope Array (ATA) located in Northern California is a radio telescope optimized for the Search for Extraterrestrial Intelligence (SETI). The instrument is composed of 42 directional randomly distributed antennas with a maximum baseline of 300 meters. The recently upgraded cryo-cooled log-periodic antenna feed (Antonio Feed) is sensitive to a wide range of frequencies, 0.9-12 GHz. The digital signal processing software is comprised of a real-time correlator and beamformer that can be utilized for SETI, fast radio burst, and other kinds of radio astronomy science.

The received RF signal from each antenna is transmitted to a central processing room using a fiber-optic cable and digitized using a real-valued ADC onboard a Xilinx RFSoC. The digitized data are pre-channelized, filtered, and streamed down the chain via a 100GbE network. This pre-channelization step is based on a polyphase filterbank to achieve an excellent level of spectral leakage suitable for mitigating unwanted electromagnetic interference. The output of the polyphase filterbank frontend, i.e. the pseudo-IQ samples, are then FFT'ed to achieve channelization.

Inverting the critically-sampled polyphase filterbank is a lossy operation. However, the digitally filtered pseudo-IQ data can be used to demodulate strong terrestrial signals, such as LTE downlinks. Converting the ATA data to pseudo-IQ allows most of the Open-Source science dataset generated by the ATA to be used by GNU Radio.

To make the conversion process easily accessible to the user, we developed a GNU Radio Out-of-Tree (OOT) module that reads a GUPPI file generated by the telescope pipeline and outputs a pseudo-IQ complex stream ready to be used with standard blocks.

In this talk, I will explain the Allen Telescope Array processing pipeline, demonstrate the conversion of a GUPPI file into pseudo-IQ using the GNU Radio Out-of-Tree block, and illustrate what is possible to do with such data inside the GNU Radio Companion.

Speaker: Luigi Cruz (SETI Institute)

GNUPresFinal.pdf

GNUPresFinal.pptx

13:00 → 15:00 Workshop

13:00 TorchSig: An open-source signals processing machine learning toolkit

In this workshop, we dive into our newly-introduced RFML toolkit, TorchSig. We step through the installation process, dataset generation examples, data augmentation pipelines, and example training scripts using the Sig53 dataset as well as fine-tuning to over custom datasets. Please join us for this code walkthrough and bring any questions on the toolkit’s capabilities and how it can be tailored for your specific use-cases.

Speaker: Dr Garrett Vanhoy (Peraton Labs)

TorchSigWorkshop_GRCon.pdf

14:45 → 15:00 Lightning Talk Block

15:00 → 15:20 PM Break

15:20 → 16:50 Main Track

15:20 Software-defined mmWave Initial Access using GNU Radio

Millimeter-wave (mmWave) communications is gaining traction with commercial deployments, but the research community still lacks experimental platforms for prototyping and validating their contributions in real-world settings. Due to the prohibitive cost and complexity of developing Software-defined Radios (SDRs) that natively operate in the mmWave band, a few research efforts explore bridging inexpensive SDR platforms that operate in the sub-6 GHz band with commercial mmWave front-ends that up/down-convert the sub-6 GHz signals to/from the mmWave band, creating programmable mmWave platforms. These platforms mainly focus on using SDRs to control link-level aspects of the mmWave front-ends, e.g., gain, transmission mode, and beam selection, for performing experiments to characterize the mmWave front-ends' irradiation patterns, signal-to-noise ratio, and bit error rate. To the best of our knowledge, no existing open-source programmable mmWave platforms support experimentation with system-level design aspects of mmWave communications such as the initial access (IA), an essential procedure where mmWave radios locate each other and identify the best transmission-reception beam pair to establish communication.

During the IA procedure, mmWave radios iterate over their respective beam codebooks, transmitting reference signals on each probed beam and, by measuring their received power, determining the most suitable beam pair to establish a data link. While the IA procedure is essential to establish and maintain communication between mmWave radios, it also induces substantial delay and decreases the amount of resources available for communication. These overheads scale proportionally to the product of the number of antenna elements on the transmitter and receiver and will become a critical bottleneck as future mobile networks move higher up the frequency spectrum towards THz frequencies, where the number of antenna elements increases to the hundreds. To address this glaring inefficiency of the IA procedure, researchers have proposed many approaches to optimize the procedure by, for example, reducing the number of probed beams. There is a need to develop platforms that allow researchers to experiment and validate their IA methods in over-the-air scenarios.

Recognizing that need, we propose a software-defined mmWave radio framework for experimentation with the IA procedure. We implement our software-defined mmWave radio framework as a GNU Radio Out-of-Tree (OOT) module composed of control and signal processing blocks that serve different functions of the IA procedure, namely: (i) interfacing with the mmWave front-end and controlling the physical hardware; (ii) deciding the beam sweeping set; (iii) collecting and processing metrics that indicate the performance of the current beam pair; and (iv) deciding the best beam pair for data transfer. Such modular design allows experimenters to easily change or replace components of the IA procedure, e.g., the range of beams, sweeping time, and the decision algorithm, and focus only on the relevant implementation aspects of their experimental research.

In this presentation, we introduce our implementation of the software-defined mmWave framework for experimentation on IA. We show how our platform can successfully control a pair of InterDigital's Master Head Unit (MHU) v3 mmWave front-ends through a USRP's GPIO interface to perform reconfigurable and extendable IA, allowing us to evaluate the impact of the range of beams, sweeping time, and the decision algorithms on the IA performance. To facilitate the use of our software-defined mmWave framework by the broader research and development communities, we also define the control logic of the mmWave front-ends via the GPIO interface through platform-dependent configuration files, which can be tailored according to different mmWave front-end models and vendors.

Speaker: Dr Joao Santos (Virginia Tech)

Santos - GRCon 2022 Slides.pdf

15:35 Europa, ocean worlds, and harsh environment missions: wireless acoustic data transfer through ice facilitated through model integration with GNU Radio

Jupiter’s moon Europa is a target of high scientific interest to the planetary science and astrobiology community due to its liquid-water ocean beneath a many kilometers-thick ice shell [1,2]. Future ice shell penetrating missions aiming to investigate the potentially habitable under-ice environment require SWAP-limited (Size Weight and Power) technology and auxiliary systems. Potential mission architectures include a hybrid melting and drilling vehicle that unspools a fiber optic tether in its wake for primary communications (comms) as well as integrated signal repeaters as a backup wireless data transfer system. The wireless system must have a small form factor (< 30 cm ⌀) and be robust to water/ice mixtures, brine pockets, and/or salt deposits within the ice [3]. One potential solution for the repeaters are wireless acoustic devices that have a small footprint. Acoustic communication has heritage in both water and ice in polar environments, achieving extremely long range communication underwater [4, 5]. Within the ice, acoustic communication has the potential added benefit of characterizing the ice. Simple acoustic signals have been sent through >1km of ice [6], and recent experiments have successfully transmitted modulated data through ice-water mixtures using hydrophones (3-6kHz) [7, 8]. While acoustics provide an inherently lower data rate than RF, the lower power requirements and robust nature of low frequency signals could provide valuable communication needs not only for outer planet missions, but for similarly constrained endeavors on Earth, such as Autonomous Underwater Vehicle/Remote Operated Vehicle polar exploration under ice. Due to ice-cover, real-time correctional updates via GPS or RF are limited and minimizing navigational drift is an open area of research. In this environment, long-lasting wireless acoustic pucks may offer a waypoint solution for navigational correction when placed near the ice-ocean interface or within an ice shelf.
While acoustic frequency signaling has been used in the target environment, models for estimating and optimizing data transfer for through-ice communication in this frequency range have not been found in the literature. To accomplish this task I developed an acoustic-attenuation-through-ice model and integrated it with GNU Radio, which has provided a realistic signal chain for the addition of modulation. Custom blocks for attenuative parameters (salt concentration, scattering, geometric loss, directionality, etc) allow the user to model propagation based on estimates (or known values) of the environment’s in-ice properties, along with custom blocks for seawater absorption. The calculations for each block are based on empirical equations from in-situ experiments, and show an increase in attenuation with frequency; current estimates for optimized frequency ranges fall between 10-30kHz [9]. Here, I present the custom attenuation blocks coupled with an FSK modulation scheme. Ice attenuation parameters will be characterized in the lab to verify the model, and flowgraphs will be integrated into a Raspberry Pi-based custom acoustic modem for real-world testing using commercial acoustic transducers.

1. Pappalardo, R. T., et al. “Geological Evidence for Solid-State Convection in Europa’s Ice Shell.” Nature, vol. 391, no. 6665, 6665, Jan. 1998, pp. 365–68. www.nature.com, https://doi.org/10.1038/34862.
2. McKinnon, William B. “Convective Instability in Europa’s Floating Ice Shell.” Geophysical Research Letters, vol. 26, no. 7, 1999, pp. 951–54. Wiley Online Library, https://doi.org/10.1029/1999GL900125.
3. Schmidt, B. E. “Vertical Entry Robot for Navigating Europa (VERNE): An Ice- and Ocean-Profiling Thermomechanical Subsurface Mission to Search for Life on Europa.” In Revision, 2021.
4. Sánchez, Antonio, et al. “An Ultra-Low Power and Flexible Acoustic Modem Design to Develop Energy-Efficient Underwater Sensor Networks.” Sensors, vol. 12, no. 6, May 2012, pp. 6837–56. DOI.org, https://doi.org/10.3390/s120606837.
5. Semburg, Benjamin. “HADES - Hydrophone for Acoustic Detection at South Pole.” Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, vol. 604, no. 1–2, June 2009, pp. S215–18. arXiv.org, https://doi.org/10/fdd75w.
6. Abbasi, R., et al. “Measurement of Acoustic Attenuation in South Pole Ice.” Astroparticle Physics, vol. 34, no. 6, Jan. 2011, pp. 382–93. ScienceDirect, https://doi.org/10/dssjz6.
7. Han, Xiao, et al. “Cross-Ice Acoustic Communication by Ice-Mounted Geophones: An Initial Experimental Demonstration.” Applied Acoustics, vol. 150, July 2019, pp. 302–06. ScienceDirect, https://doi.org/10/gk6jd4.
8. Yin, Jingwei, et al. “Cross-Ice Acoustic Communication: Cascade Acoustic Channel Model and Experimental Results.” China Communications, vol. 18, no. 2, Feb. 2021, pp. 228–40. IEEE Xplore, https://doi.org/10/gmskck.
9. Lishman, Ben, et al. “Assessing the Utility of Acoustic Communication for Wireless Sensors Deployed beneath Ice Sheets.” Annals of Glaciology, vol. 54, no. 64, ed 2013, pp. 124–34. Cambridge University Press, https://doi.org/10/gf2zcx.

Speaker: Sara Pierson (Georgia Institute of Technology)

Europa, Ocean Worlds, and Harsh Environment Missions: Wireless acoustic data transfer through ice facilitated through model integration with GNU Radio

SPierson_GR Con 2022 Talk.pptx

15:50 High-Speed Sensing of the Electromagnetic (EM) Environment for Cognitive Radio Receivers

In this paper, we demonstrate an EM environmentally aware (EMEA) radio called the Intelligent Transceiver Radio Node or ITRN, which is suitable for use in cognitive radio applications. The ITRN is an end-to-end solution that can quickly find interferers and act upon them defensively (e.g. filter, move the channel, move to different band, change modulation, etc). While the ITRN is capable of finding interferers in both the spectral and angular domains we present a framework that allows for future expandability into more measurement domains.
To break the scanning time vs. spectral and angular resolution tradeoff, we employ compressed sensing (CS). By making a few assumptions about the local EM environment’s current state, we can perform spatial and spectral scans that are 10 times faster than the current state of the art. Information on the spectral locations of the interferers along with a current quality of service (QoS) estimate is then sent to a machine learning based decision engine (MLBDE) where reinforcement learning is used to determine the optimal channel selection.
For the ITRN’s sensor, we use a custom, 8 antenna RF-ASIC fabricated in TSMC 65nm CMOS called the Direct Space to Information Converter (DSIC). The output of the DSIC is fed to an Ettus X310. A custom UHD interface was constructed in the FPGA to speed up the streaming data rate by using a variable data packet size. Custom UHD circuitry was also created to synchronize the DSIC with the clock on the X310. In GNURADIO, we perform the baseband DSP and Orthogonal Matching Pursuit (OMP), which is used to recover the spectral locations of the interferers. Lastly, the output of OMP along with a QoS estimation is sent to the MLBDE, which calculates the new optimal channel selection and retunes the ITRN.
In this paper we describe the multi-disciplinary design process of the ITRN, system parameter selection, tradeoffs and lastly a discussion and comparison to other cognitive radio architectures with a focus on sensing time and system scalability.

Speakers: Matthew Bajor, Con Pappas

GR-Con_slides_rev11.pdf

GR-Con_slides_rev11.pptx

GR_con_ITRN_manuscript_rev9.pdf

ITRN_STTR_GR_abstract_rev3.pdf

Video_2_no_audio.mp4

16:20 Advanced MIMO Demonstration

Speaker: Matt Ettus

15:25 → 16:55 Workshop

15:25 GR 4.0 Tutorial

This workshop explores the new features of GNU Radio 4.0 (in preview release by the time of the conference) in a hands-on manner. Learn about the development methodology, workflows, and the process to port a module/block from GR3.X to 4.0

Topics will include:

• New block API design
• Creating a block with the new design methodology
• Using custom buffers
• Accelerated block implementations

Speaker: Josh Morman

GR4 OOT example

GRCon22 - 4.0 Workshop.pdf

18:00 → 21:00 GRCon22 Social: Wednesday Social

Penn Social

Thursday, 29 September

08:00 → 08:45 Conference Check-in

08:45 → 09:00 Thursday Opening

09:00 → 09:45 Keynote: Thursday Keynote

09:00 Keynote: Dr. Nicholas Laneman

Twenty Years of Utilizing Software-Defined Radio in University Research, Teaching, and Collaboration: From a Single USRP Beta to SpectrumX

This talk will share reflections on applying and developing several software-defined radio (SDR) platforms as foundational tools in academic research, teaching, and collaboration activities pursued by my group at the University of Notre Dame over the past 20 years. Motivated by a desire to connect theory and real-world prototyping, we have also evolved an SDR-based lab course in an attempt to provide experiential learning opportunities and to lower barriers for students to be productive. Recent efforts are expanding through SpectrumX, the first NSF Spectrum Innovation Center, with opportunities to engage a broader audience of scientists, engineers, and policymakers. Upon this backdrop, I will suggest a few challenges and opportunities for the SDR community to consider going forward.

Speaker: Dr Nicholas Laneman (SpectrumX)

09:00 → 15:00 Workshop

09:00 Amateur Radio Exam Review

Dan Romanchik KB6NU from ARDC is putting on a Tech class review Q&A prior to the Amateur Radio exams. Feel free to use this room for individual studying, or to get help from Dan. It is highly recommended to start studying prior to GRCon, Dan has created a series of free Technician Class study guides which can be found here https://www.kb6nu.com/study-guides/

Speaker: Dan Romanchik (ARDC)

09:45 → 10:45 Main Track

09:45 Passive reception of Two-Way Satellite Time and Frequency Transfer (TWSTFT) signals from a geostationary satellite, or GPS upside down

As part of International Atomic Time (TAI -- Temps Atomique International) definition, national observatories regularly share their atomic (hydrogen, cesium ...) clock signals through geostationary satellite links. The Two Way Satellite Time and Frequency Transfer (TWSTFT) system has been developed to cancel the impact of the microwave link and synchronize clocks distributed continents away with sub-ns accuracy (light travels 30 cm during 1 ns).
These signals are broadcast over the ether and accessible to any knowledgeable user who might want to synchronize their clock.

Geostationary satellites, usually considered at a fixed location above the equator, are however subject to gravitational forces and must remain within a window size of 0.1 degree, or a sphere of 30-km radius (light travels 30 km in 100 us). The challenge in compensating for the impact of varying position of the geostationary satellite for accurate synchronization of clocks in a passive reception scheme lies in identifying the satellite location and compensating for its variation.

While Global Navigation Satellite Systems (GNSS) including the Global Positioning System (GPS) rely on spaceborne atomic clocks for accurate time transfer to the receiver allowing by trilateration for positioning and timing (Position, Velocity and Time -- PVT -- solution), we will show in this presentation that

• the TWSTFT signal are readily received with a consumer-grade satellite-TV reception parabolic reflector antenna fitted with a Software Defined Radio (SDR) receiver able to collect signals around 1.2 GHz on a 5-MHz bandwidth
• correlation and super-resolution using parabolic fit of the correlation peak allows for sub-ns timing resolution despite the 4-MHz bandwidth signal
• the spatial diversity of the emitting references, assumed to be synchronized, allows for recovering the attitude of the satellite,
• that publicly available ranging measurements from these reference sources match the observations.

Hence, accurate timing of passive receivers of TWSTFT requires solving issues reminiscent of GPS ... upside down.

Speaker: Jean-Michel Friedt (FEMTO-ST/Time & Frequency, Besancon, France)

Proceeding manuscript

Short teaser

Slides

10:15 An ultra reliable low latency over-the-air communication system in GNU Radio for automated guided vehicles

We present our ultra reliable low latency over-the-air communication system implementation in GNU Radio. This includes our Out-of-Tree modules for multicarrier synchronization, GFDM modulation, polar coding, and symbol mapping. We demonstrate how we use GNU Radio with USRPs on our Automated Guided Vehicles (AGVs) and as part of our base station to realize a full transceiver. This will include pictures and hands on descriptions how we integrate all components.

We want to discuss our measurement results in this talk. This includes SNR measurements over our testbed area as well as latency measurements. Finally, we want to show videos to give the audience a better feeling for what we implemented to run our AGVs.

Speaker: Johannes Demel (University of Bremen)

agvdemo.mp4

Department of Communications Engineering website

presentation.pdf

git repositories

• gr-gfdm
• gr-latency
• gr-polarwrap
• gr-symbolmapping
• polar-codes
• XFDMSync

10:45 → 11:00 AM Break

10:45 → 16:00 Capture the Flag (CTF)

Capture the flag (CTF) is a competition where contestants earn points by finding secret messages ("flags") hidden in radio signals. Challenge yourself and improve your GNU Radio skills!

GRCon22 CTF

10:45 → 15:00 Expo Hall

Sponsors

11:00 → 11:45 Main Track

11:00 DIFI: The Universal Language for Streaming Digitized RF

DIFI is a new IEEE open standard for streaming digitized RF/IF samples and corresponding metadata over standard IP networks, opening potential for true interoperability between SDRs and real-time signal processing hardware and software. DIFI is a specific schema for VITA 49.2, and it uses UDP as the transport layer. DIFI was originally tailored to overcome the vendor lock-in that has been ubiquitous in the satellite industry, but it has since expanded for use beyond satellite applications. In this talk we provide an overview of the DIFI protocol and show off some example use-cases, including using the GNU Radio DIFI blocks maintained by the DIFI Consortium (gr-difi). We go over the pros and cons of using DIFI versus other data planes for carrying high-rate IQ samples over a network, e.g., between a GNU Radio flowgraph and another software or hardware component. Lastly, we will demonstrate how DIFI can be used along with SigMF, for offline archival of RF data.

[1] IEEE-ISTO Std 4900-2021: Digital IF Interoperability Standard, v1.0 – August 18, 2021
[2] https://github.com/DIFI-Consortium/gr-difi

Speakers: Christian Rodriguez (Microsoft and DIFI Consortium), Jose De La Cruz (Microsoft)

GRCon22 DIFI Talk.pdf

test.txt

11:30 Epiq Solutions: Sensor Open Systems Architecture (SOSA) and SDRs

The goal of the Sensor Open System Architecture (SOSA) consortium is to develop an open architecture for Communications (Comms), Electro-Optical/Infra-Red (EO/IR), Electronic Warfare (EW), Radar, and Signals Intelligence (SIGINT) systems. This talk serves as an introduction to SOSA and how SDRs fit into this open architecture.

Speaker: Lorin Sandler (Epiq Solutions)

11:00 → 12:00 Workshop

11:00 Signal Representations for Communication Systems

This presentation gives an overview of mathematical concepts used for signal representation in communication systems. Topics covered include: baseband/bandpass signals; signal duration/bandwidth and the time-bandwidth product; representations of bandpass signals in terms of baseband equivalents (I/Q components and envelope/phase); signal mixing and the superheterodyne principle; sampling and quantization.

Speaker: Dr Dimitrie Popescu (Old Dominion University, ECE)

11:45 → 12:00 Lightning Talk Block

12:00 → 13:00 Lunch

13:00 → 14:45 Main Track

13:00 Implementation of Faster-Than-Nyquist (FTN) Signaling using Software Defined Radios

In this work, we develop and implement a Faster Than Nyquist (FTN) signaling system using a Binary Phase-Shift Keying modulation (BPSK). The popular open-source, and radio-specific, signal processing application GNU Radio was used to develop transmitter and receiver architectures. These architectures were then deployed for execution on a variety of Software Defined Radio (SDR) hardware. The final aim of the project is to experiment with a novel demodulation technique recently applied to FTN systems known as Probabilistic Data Association (PDA.) Since the seminal works of [1–3] showed that it would be possible to exceed the Nyquist signaling rate while maintaining an equivalent bit error rate (BER) performance, researchers have proposed many novel and creative methods for the implementation of a Faster-than-Nyquist (FTN) system. A large majority of these works have concentrated on the development of algorithms for mitigating or undoing the effects of intentionally introduced inter- symbol interference (ISI.) Furthermore, many of the works have relied purely on results produced from simulated models of FTN signaling. The reason for this being that these methods have very high computational complexity and would introduce far too great of an overhead cost on hardware, for example the turbo encoded and trellis based transceivers proposed in [4, 5]. However, there have been some works that have discussed and even attempted implementations of both FTN transmitters and receivers. These implementations have predominately been concentrated in the areas of non-orthogonal frequency domain multiplexing (NOFDM) and multi-carrier systems. With regards to an FTN transmitter architecture, [6] proposes a look up table (LUT) based transmitter architecture for an OFDM system. The LUT implements a mapping of offset-QAM symbols to set of pre-computed optimum FTN symbols for input into a traditional OFDM transmitter. In [7] the proposed FTN mapping system is actually implemented targeting a FPGA device. In [8] yet another transmitter architecture is implemented on FPGA but for a so called Spectrally Efficient Frequency Division Multiplexed (SEFDM) system, which intentionally overlaps carriers in OFDM. The SEFDM signal generated by hardware is compared to simulated models. The proposed FTN mapper system in [7] is combined with an FTN receiver for a full transceiver system on FPGA hardware in [9]. The transceiver has the ability to default to standard OFDM signaling depending on the quality of the channel. Follow up papers for this transceiver system [10, 11] make improvements in the VLSI parameters of memory, area and power consumption. The works discussed above are the only attempts made at hardware based implementation of an FTN communication system, to our knowledge. All these works use FPGAs and target more advanced communications schemes. In this work we seek to utilize existing Software Defined Radio (SDR) hardware and the digital communications toolbox GNU Radio to implement a FTN transceiver based on a low-complexity probabilistic data association algorithm (PDA) [12]. The transceiver intentionally employs a basic binary phase-shift keying (BPSK) scheme with root-raised cosine (RRC) pulse shaping filters. The implementation of our FTN BPSK transceiver was carried out partially in GNU Radio and in MATLAB. The SDR used was National Instruments (NI) USRP 2920.

References
[1] D. Tufts, “Nyquist’s problem—the joint optimization of transmitter and receiver in pulse amplitude modulation,” Proceedings of the IEEE, vol. 53, no. 3, pp. 248–259, 1965.
[2] B. Saltzberg, “Intersymbol interference error bounds with application to ideal bandlimited signaling,” IEEE Transactions on Information Theory, vol. 14, no. 4, pp. 563–568, 1968.
[3] J. E. Mazo, “Faster-than-Nyquist signaling,” The Bell System Technical Journal, vol. 54, no. 8, pp. 1451–1462, 1975.
[4] A. Liveris and C. Georghiades, “Exploiting faster-than-Nyquist signaling,” IEEE Transactions on Communications, vol. 51, no. 9, pp. 1502– 1511, 2003.
[5] F. Rusek and J. B. Anderson, “Serial and parallel concatenations based on faster-than-Nyquist signaling,” in 2006 IEEE International Symposium on Information Theory, 2006, pp. 1993–1997.
[6] D. Dasalukunte, F. Rusek, J. B. Anderson, and V. Owall, “Transmitter architecture for faster-than-nyquist signaling systems,” in 2009 IEEE International Symposium on Circuits and Systems, 2009, pp. 1028–1031.
[7] D. Dasalukunte, F. Rusek, V. ̈Owall, K. Ananthanarayanan, and M. Kandasamy, “Hardware implementation of mapper for faster-than-Nyquist signaling transmitter,” in 2009 NORCHIP, 2009, pp. 1–5.
[8] M. R. Perrett and I. Darwazeh, “Flexible hardware architecture of sefdm transmitters with real-time non-orthogonal adjustment,” in 2011 18th International Conference on Telecommunications, 2011, pp. 369–374.
[9] D. Dasalukunte, F. Rusek, and V. Owall, “Multicarrier faster-than-Nyquist transceivers: Hardware architecture and performance analysis,” IEEE Transactions on Circuits and Systems I: Regular Papers, vol. 58, no. 4, pp. 827–838, 2011.
Rest of references are listed in the pdf submision.

Speakers: Mr Gregory Dzhezyan (California State University, Fresno), Prof. Hovannes Kulhandjian (California State University, Fresno), Dr Michel Kulhandjian (Rice University)

GRCon Abstract_FTN.pdf

Implementation_of_FTN_Signaling_using_SDR_paper.pdf

Implementation_of_FTN_Signaling_using_SDR_slides.pptx

13:30 Inference as DSP: An Approach to Heterogeneous Compute-Enabled SDR Applications

Constructing a framework for the development of SDR applications backed by heterogenous compute platforms has been the subject of significant development effort over a few decades, but no single framework has gained significant traction in the open-source SDR community. At the same time, machine-learning software has matured and made efficiently implementing tensor operations across CPU, GPU, and FPGA accessible even to novice developers. We present a novel GNU Radio out-of-tree (OOT) module that integrates with Triton Inference Server (TIS) -- effectively enabling highly-scalable SDR application development backed by heterogenous compute platforms. The new OOT brings exciting capabilities to the GR 3.x line of development which is currently available, but also presents the first significant use of the GR 4.x modular scheduler framework. Finally, we present a number of performance comparisons demonstrating the immediate benefit the new OOT brings to application developers.

Speaker: Garrett Vanhoy (Peraton Labs)

gr_inference_as_dsp_v3.pdf

13:45 SDR Beyond Radio: An OOT GNURadio Library for Simulation and Deployment of Multi-Cell / Multi-User Optical Wireless Communication Systems

Optical wireless communication (OWC) technologies have gained significant interest over the past two decades; however, early research focused on point-to-point links and novel modulation techniques. More recently, the field has moved towards higher layer design and analysis of multi-cell / multi-user systems, leading to novel schemes for resource allocation across devices and overlapping OWC access points; but much of this work has been based in theory and simulation. Significant effort is required to develop proof-of-concept implementations of such systems, and this limits the opportunity for experimental evaluation of novel techniques for resource allocation and/or handover. To address this, we apply software-defined radio (SDR) tools and concepts that have benefitted the RF research community. Namely, SDR has created a more equitable opportunity for research in the wireless communications field by reducing the barrier to entry and making it more feasible for researchers to physically instantiate novel ideas. We bring this accessibility to OWC systems research by developing a baseline resource allocation implementation for multi-user / multi-cell systems. By developing this implementation within widely used SDR signal processing toolkits, we can offer the module as an open-source tool for other researchers to use as a “golden reference” that can be compared with novel resource allocation techniques and/or iterative improvements to the baseline technique.
The openly available software development toolkit of GNURadio provides an ideal platform for SDR implementation. In particular, GNURadio’s Out-Of-Tree (OOT) modules allow for the addition of custom signal processing blocks. Using this feature, we have developed gr-owc, an open source OOT module for OWC. In October 2021, we published our initial version of gr-owc, with signal processing blocks for OWC channel simulation and common OWC modulation/demodulation techniques. In this work, we will describe our recent contributions to gr-owc, including further development of our DC-biased Optical OFDM (DCO-OFDM) modules and implementation of resource allocation modules for merging multiple data streams via DCO-OFDMA. We will also introduce our methods for using gr-owc to instantiate a physical OWC testbed using X310 USRPs and a combination of custom and COTS front-end OWC hardware.
As a testbed, the key benefit of SDR is that the system is built off modular design principles such that front end transmitter/receiver hardware can be interchanged, and the waveforms generated in software can be parameterized to align with the characteristics of hardware currently in use. As such, we will also introduce our custom-built multi-color OWC transmitter where each color channel can be directly driven by a single real-valued signal from the USRPs with LFTX daughter cards. This enables experimental analysis of wavelength division multiplexing (WDM) and/or wavelength division multiple access (WDMA) systems. In summary, we will present our recent work that extends the initial functionality of gr-owc to include various resource allocation capabilities for testing multi-cell and multi-user OWC systems.

Speaker: Michael Rahaim (UMass Boston)

SDR_Beyond_Radio-GRCon_Paper.pdf

SDR_Beyond_Radio-GRCon_Pres.pptx

14:15 Using FIT/CorteXlab for the Evaluation of Access Policies in Dense IoT Networks through S3CAP, a New Modular Framework

FIT/CorteXlab is a radio testbed composed of 42 software defined radio nodes, among which, NI USRPs and Nutaq’s PicoSDRs. These nodes are enclosed in a shielded and semi-anechoic room, isolated from the outside radio environment which promotes reproducible radio experiments. Operational since 2014, it supports state-of-the-art radio experiments, in diverse areas such as cognitive radio, radio security, deep learning for physical layers, and IoT systems, focus of this work.
IoT communication suffers from increased packet collisions due to the ever expanding number of IoT devices, and the study of new channel access policies promises to reduce energy consumption, latency and errors due to retransmission.
In this work we describe the “Slotted and Synchronized multi-Sources experimental framework for the evaluation of new Channel Access Policies” (S3CAP), a new open-source GNU-Radio framework for FIT/Cortexlab. In S3CAP, a custom access policy sets usable slots for each node to transmit to a base station in a slotted and synchronized time frame. The transmitted signal is then generated using a modular and replaceable GNU Radio physical (PHY) layer. Since its conception S3CAP has been used in several studies, and opens new opportunities in the design, evaluation and comparison of both centralized and decentralized random access strategies for future M2M communications.

Speakers: Amaury Paris (INRIA), Dr Leonardo Cardoso (INSA Lyon, INRIA)

fitcortexlab_grcon_2022.pdf

13:30 → 16:30 Amateur Radio License Exam

Amateur Radio License Exams Information

14:45 → 15:00 Lightning Talk Block

15:00 → 15:20 PM Break

15:20 → 16:50 Main Track

15:20 gr-plasma: A New GNU Radio-based Tool for Software-defined Radar

Building experimental radar systems has traditionally required expensive custom hardware. Such designs are typically difficult to program, preventing easy experimentation with new radar signal processing algorithms. While software-defined radio hardware is not inherently designed to operate as a radar, there have been numerous documented examples of software-defined radar implementations using commercial-off-the-shelf radio hardware – particularly from the GNU Radio community. In this paper and the accompanying talk, the gr-plasma out-of-tree module is presented as a convenient way to implement and test radar systems in GNU Radio. The module is an implementation of the signal processing in Plasma DSP, a separate companion library written in C++ that can be used outside the GNU Radio ecosystem. In addition to describing the operation and utilization of gr-plasma we will highlight the technical challenges we encountered in developing this software. In doing so, we hope to provide resources and motivation to enable other developers to easily use and further develop the gr-plasma architecture.

There are two key challenges with software-defined radar that differ from most communications protocols: transmit/receive synchronization and ultra-reliable high-speed duplex operation. Radar systems operate by transmitting electromagnetic waves into the environment and measuring reflections. To achieve localization accuracy, the transmit and receive processes must be synchronized down to the sample level. Additionally, the resolution of a radar sensor is inversely proportional to the bandwidth of waveform. Therefore, the software must be capable of both transmitting and receiving high-data rate streams to maximize radar performance. All of these challenges must be met in a flexible, easy-to-use software architecture to enable experimentation by both academics and hobbyists alike. We will describe the several approaches we have examined to achieve these data rates as well as compare their performance on both 10 gigabit ethernet and USB 3 links.

To date, we have focused development on pulsed radar operation, which is inherently bursty. Due to this property, gr-plasma uses GNU Radio's message passing interface to packetize each pulse into a protocol data unit (PDU). Consequently, downstream blocks may easily operate on individual pulses (e.g., for range processing) or on an integer number of pulses in a coherent processing interval. Unlike tagged stream approaches, the length of each pulse is not limited by the buffer size of each block, which becomes a limiting factor at high sample rates even when the pulse repetition interval (PRI) is small.

The gr-plasma module includes tools for natively generating linear FM (LFM) and arbitrary polyphase-coded FM (PCFM) waveforms, as well as any other arbitrary waveform desired from a file. These waveforms can be transmitted and received through UHD-compatible software-defined radios using a custom USRP Radar block. Rather than requiring a time-stamped PDU for every pulse, the block repeatedly transmits the data from the last PDU it has received and handles all pulse timing internally. This reduces the number of messages that must be processed during streaming while simplifying the design of the block. This architecture also facilitates “cognitive operation” with low latency. For example, an adaptive waveform controller block can use the results of downstream processing to send a message with an updated waveform that is processed on a sub-millisecond time scale. Moreover, the radar block can sustain similar sample rates in GNU Radio as in pure UHD because it does not incur any overhead from the GNU Radio scheduler. This functionality is key for research in radar operation in congested spectrum, such as dynamic spectrum access (DSA) applications. Finally, the module includes a custom file sink block for saving data from large PDUs, which also saves metadata that complies with the SigMF v1.0.0 standard or select extensions. This final feature is of key significance as software-defined radar research involves pulse-to-pulse changes in the radar waveform (e.g., for spectral co-existence, radar-embedded communications, or other emerging research topics) that challenge traditional metadata formats. In the final paper and presentation, the utility and structure of each block will be discussed, challenges that arose during development will be described, and the results of range-doppler processing will be shown for data collected with gr-plasma and an Ettus X310 in an open-air test. Depending on travel costs and conference setup, an attempt will be made for a live demonstration of the gr-plasma framework using a laptop, two low-cost ultra wideband Vivaldi antennas, and an Ettus radio (either an X310 or B210). This demonstration would be arranged with the conference organizers to ensure spectrum authorization and space to demonstrate.

Speaker: Shane Flandermeyer (School of Electrical and Computer Engineering, Advanced Radar Research Center, University of Oklahoma)

Flandermeyer2022- gr-plasma_a new GNU Radio-based tool for Software-defined Radar.pdf

gr-plasma github repository

plasma-dsp github repository

saf_grcon22.pptx

15:50 Sparrow: A new broadband software radio development platform

We present a novel radio development platform with special customization features designed for a range of software-defined radio applications. The "Sparrow" board has been inspired by radio astronomy research and is a high-speed, dual input data acquisition system capable of digitizing signals with bandwidths up to 400 MHz. The mainboard is a baseband receiver that comes with a horizontally attached mezzanine card that can house a multi-channel high-speed DAC for TX functionality or other RF signal processing. The platform also relies on silent switching DC converters for ultra-low-noise applications.

Sparrow is based on the Zynq-7000 ARM/FPGA SoC and is compatible with the XC7Z030/35/45 chips. One of the main advances of this platform is its synchronization capabilities. In addition to 1PPS and reference inputs, the board can be locked to a White-Rabbit timing distribution system, enabling sub-nanosecond synchronization of multiple boards. It features four SFP+ ports - allowing up to 40 Gb/s of streaming output - as well an RJ45 Ethernet port, USB, and an SD card.

Sparrow has been developed to plug into RF daughterboards, with several reference designs being developed, including an 8GHz downconverter as well as an IQ board. Most importantly, our goal is to make the KiCAD-6 design files of the mezzanine cards and daughterboards completely open-source allowing users to modify or design their own.

Speaker: Dr Nima Razavi-Ghods (University of Cambridge)

GRCON22_NRG.pdf

GRCON22_NRG.pdf

16:20 BBC Secure Communications

Wireless capabilities such as GPS, ADS-B (i.e. MODE-S), and encryption key-sharing can be seriously degraded or denied in the presence of intentional or unintentional jamming. Give the prolific availability of inexpensive SDRs – robust and secure encryption is more important than ever. This project implements a proof-of-concept for the “BBC” codec – a novel keyless, concurrent-codes approach to jam-resistant communications. GNU Radio is an effective testbed for measuring BBC’s preservation of information availability under a variety of modulation types and attack strategies. Development is underway to provide a BBC library for broader use within the GNU Radio community.

Speaker: Mr James Morrison (USAFA)

GRCon_BBC_2022_paper.pdf

GRCon_BBC_2022_slides.pdf

16:50 → 17:05 Project Talk: GRCon Main Track Closing

Friday, 30 September

09:00 → 09:30 Friday Hands-On Opening

09:30 → 15:00 Hands-On Day/Hackathon

10:00 → 14:00 Project Talk: Hands-On Day

10:00 GR 4.0 Block Party

12:00 → 13:00 Friday Snacks

Full lunch not provided... but there will snacks!

13:00 → 15:00 Capture the Flag (CTF)

Capture the flag (CTF) is a competition where contestants earn points by finding secret messages ("flags") hidden in radio signals. Challenge yourself and improve your GNU Radio skills!

GRCon22 CTF

13:00 Capture the Flag (CTF) Review

Speaker: Clayton Smith