Network Radar Pipeline

Authors: Dylan Eustice (NVIDIA)
Supported platforms: x86_64, aarch64
Last modified: March 18, 2025
Language: C++
Latest version: 1.1
Minimum Holoscan SDK version: 0.6.0
Tested Holoscan SDK versions: 0.6.0
Contribution metric: Level 2 - Trusted
The Network Radar Pipeline demonstrates signal processing on data streamed via packets over a network. It showcases the use of both the Advanced Network Operator and Basic Network Operator to send or receive data, combined with the signal processing operators implemented in the Simple Radar Pipeline application.

Using the GPUDirect capabilities afforded by the Advanced Network Operator, this pipeline has been tested up to 100 Gbps (Tx/Rx) using a ConnectX-7 NIC and A30 GPU.

The motivation for building this application is to demonstrate how data arrays can be assembled from packet data in real-time for low-latency, high-throughput sensor processing applications. The main components of this work are defining a message format and writing code connecting the network operators to the signal processing operators.

This application supports the Advanced Network Operator DPDK and DOCA GPUNetIO transport layers.

Prerequisites

See the README for the Advanced Network Operator for requirements and system tuning needed to enable high-throughput GPUDirect capabilities.

Environment

Note: Dockerfile should be cross-compatible, but has only been tested on x86. Needs to be edited if different versions / architectures are required.

Build

Please refer to the top level Holohub README.md file for information on how to build this application: ./run build network_radar_pipeline.

Run

Note: must properly configure YAML files before running. To run with DPDK as ANO transport layer: - On Tx machine: ./build/applications/network_radar_pipeline/cpp/network_radar_pipeline source.yaml - On Rx machine: ./build/applications/network_radar_pipeline/cpp/network_radar_pipeline process.yaml

To run with DOCA GPUNetIO as ANO transport layer: - On Tx machine: ./build/applications/network_radar_pipeline/cpp/network_radar_pipeline source_doca.yaml - On Rx machine: ./build/applications/network_radar_pipeline/cpp/network_radar_pipeline process_doca.yaml

For Holoscan internal reasons (not related to the DOCA library), build the Advanced Network Operator with RX_PERSISTENT_ENABLED set to 1 MAY cause problems to this application on the receive (process) side (receive hangs in process.cu file). If you experience any issue on the receive side, please read carefully in the Advanced Network Operator README about how to solve this problem.

Network Operator Connectors

See each operators' README before using / for more detailed information.

Basic Network Operator Connector

Implementation in basic_network_connectors. Only supports CPU packet receipt / transmit. Uses cudaMemcpy to move data between network operator and MatX tensors.

Advanced Network Operator Connector

Implementation in advanced_network_connectors. RX connector is only configured to run with GPUDirect enabled, in header-data split (HDS) mode. TX connector supports both GPUDirect/HDS or CPU-only.

Testing RX on generic packet data

When using the Advanced network operator, the application supports testing the radar processing component in a "spoof packets" mode. This functionality allows for easier benchmarking of the application by ingesting generic packet data and writing in header fields such that the full radar pipeline will still be exercised. When "SPOOF_PACKET_DATA" (adv_networking_rx.h) is set to "true", the index of the packet will be used to set fields appropriately. This functionality is currently unsupported using the basic network operator connectors.

Message format

The message format is defined by RFPacket. It is a byte array, represented by RFPacket::payload, where the first 16 bytes are reserved for metadata and the rest are used for representing complex I/Q samples. The metadata is: - Sample index: The starting index for a single pulse/channel of the transmitted samples (2 bytes) - Waveform ID: Index of the transmitted waveform (2 bytes) - Channel index: Index of the channel (2 bytes) - Pulse index: Index of the pulse (2 bytes) - Number samples: Number of I/Q samples transmitted (2 bytes) - End of array: Boolean - true if this is the last message for the waveform (2 bytes)