Why SDR on‑truck?
- One platform, many signals: monitor ISM IoT (433/868/915 MHz, 2.4 GHz), BLE/Wi‑Fi beacons, and research bands with reconfigurable software.
- Coverage validation: map packet reception for your smart bins/sensors and spot dead zones.
- Spectrum hygiene: find interference sources near depots/transfer stations and verify your assets are on‑channel.
Use cases (illustrative)
- Ad‑hoc ISM sniffers: receive LoRa/FSK/ASK/OOK at 433/868–915 MHz to validate your devices and coverage (e.g., smart‑bin nodes). Tooling like rtl_433 decodes hundreds of simple ISM devices.
- Spectrum surveys: record power spectral density / waterfalls to understand band occupancy and interference along routes. See wideband receivers such as SDRplay RSPdx or SDRs like USRP B210.
- V2X/ITS research pilots: with authorization, log basic C‑V2X channel activity at 5.9 GHz (not message content). Reference: FCC C‑V2X actions in 5.9 GHz.
- Asset QA: verify that your RFID/telematics beacons transmit at the right frequency and power; alert when expected bursts go missing.
Bands & common protocols
| Band | Examples on‑truck | Notes/Refs |
|---|---|---|
| 433/868/915 MHz ISM | LoRa/FSK/OOK bin tags, temp beacons, proprietary links | FCC Part 15 (unlicensed devices) • LoRaWAN regional parameters |
| 2.4 GHz ISM | BLE beacons, Wi‑Fi cameras/telematics | Bluetooth Core • IEEE 802.11 |
| 5.9 GHz ITS | C‑V2X sidelink activity (research pilots) | FCC 5.9 GHz C‑V2X |
Hardware tiers (representative)
| Tier | Device | Coverage | Typical use | Refs |
|---|---|---|---|---|
| Entry (RX‑only) | RTL‑SDR Blog V3 | ~24 MHz–1.7 GHz | Cheap ISM/BLE scans; rtl_433 decoding | RTL‑SDR Blog |
| Mid | HackRF One / LimeSDR Mini | ~1–6 GHz (HackRF); up to 3.5 GHz (Lime Mini) | General RX/TX experiments; moderate bandwidth | HackRF • LimeSDR Mini |
| Pro | USRP B210 / SDRplay RSPdx | 70 MHz–6 GHz (B210, 2×2 MIMO); 1 kHz–2 GHz (RSPdx, 14‑bit) | High‑quality IQ capture; wide scans | USRP B210 • RSPdx |
Antennas & RF front‑end
- Antennas: roof‑mounted 433/868/915 MHz whips; 2.4/5 GHz puck; ensure a good ground plane.
- Filtering & gain: SAW/bandpass pre‑selectors and low‑noise amplifiers (LNA) sized to your band plan improve weak‑signal SNR. Example vendors: Mini‑Circuits filters, NooElec LNAs.
- Installation: use mag‑mounts or brackets, weatherproof coax runs, and DC isolation where the truck’s electrical noise is high.
Software stack
Compliance & privacy (read me)
- In the U.S., most on‑truck monitoring uses unlicensed bands governed by 47 CFR Part 15. Do not intercept protected communications or cellular traffic.
- Restrict demodulation/recording to your own fleet devices, open beacons, and lawful spectrum measurements. For 5.9 GHz C‑V2X pilots, follow FCC guidance and local authorizations.
- Publish what you collect, minimize PII (blur plates/faces if using video), and set retention limits.
Mini‑BOM (starter kit)
| # | Item | Purpose | Link | Notes |
|---|---|---|---|---|
| 1 | SDR (choose tier) | IQ capture / scanning | RTL‑SDR Blog V3 • HackRF One • USRP B210 | Select based on bandwidth & dynamic range needs |
| 2 | Antennas | 433/868/915 MHz, 2.4/5 GHz | NooElec antennas | Mag‑mounts with ground plane |
| 3 | Filters & LNA | Improve SNR; reject out‑of‑band | Mini‑Circuits filters • LNA modules | Pick passband per target frequencies |
| 4 | Edge compute | Run DSP & logging | Jetson Orin Nano • Raspberry Pi 5 | Containerize GNU Radio/rtl_433 services |
| 5 | Timing & GPS | Geo‑tag & time‑align | u‑blox GNSS | Use PPS if you need tight time alignment |
Sources (selected)
- FCC rules & guidance: 47 CFR Part 15 (unlicensed) • FCC actions on 5.9 GHz C‑V2X.
- SDR hardware: RTL‑SDR Blog V3 • HackRF One • LimeSDR Mini • USRP B210 • SDRplay RSPdx.
- Software & tooling: GNU Radio • SoapySDR • rtl_433 • Kismet.
- RF front‑end parts: Mini‑Circuits bandpass/SAW filters • NooElec LNAs.
- LoRaWAN references: LoRa Alliance regional parameters.
- BLE/Wi‑Fi specs: Bluetooth Core Spec • IEEE 802.11.