May 20th to May 26th, 2024 – Welcome Post

Welcome to the first post of the DragonOS blog. Since its origin in 2019, DragonOS has aimed to deliver valuable and accessible tools to those who use softhttps://cemaxecuter.com/?p=320#ib-toc-anchor-1ware-defined radio (SDR) radios. The creator, Cemaxecuter, hopes DragonOS will become the go-to resource for SDR just as Kali Linux is a one-stop-shop for the offensive security and digital forensics fields.

This blog adds to the extensive resources that DragonOS provides by publishing weekly content covering the latest developments in the SDR world and their impact on DragonOS. If you are not already familiar, below are links to all of the sites where you can currently engage with DragonOS:

• DragonOS Source for x86_64 systems: https://sourceforge.net/projects/dragonos-focal/
  • Download the latest release of DragonOS for x86_64 systems, ask for support, and read about the history of DragonOS.
• DragonOS Source for Pi64 systems: https://sourceforge.net/projects/dragonos-pi64/
  • Download the latest release of DragonOS for Pi64 systems, ask for support, and read about the history of DragonOS.
• Cemaxecuter on YouTube: https://www.youtube.com/channel/UC9U2kaqhE716J2WNSTcOghg
  • Follow along with Cemaxecuter himself as he walks you through how to use specific SDR tools within DragonOS and explains why they are valuable.
• DragonOS Discord Channel: https://discord.com/invite/cYuS3E3k
  • Join the community of DragonOS users to share your work, ask for help, or lurk for content
• Cemaxecuter on X: https://x.com/cemaxecuter
  • Recent updates from the creator of DragonOS
• DragonOS Patreon: https://www.patreon.com/cemaxecuter
  • 100% of contributions fund advanced features, videos, and hardware. As a thank you, Cemaxecuter will ask for your feedback on experimental features.
• For collaboration please contact cemaxecuter directly at cemaxecuter@protonmail.com

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Drones are everywhere. They present dazzling light shows at concerts, provide engaging cinematography shots, and have many functional uses in construction, farming, and medicine. Unfortunately, drones can also present significant personal safety risks at home, airports, and even the battlefield. To deter malicious and negligent behavior with drones the FAA mandated all drone operations outside of FAA Recognized Identification Areas (FRIAs) must have Remote ID. Read more about the background and rules here: https://www.faa.gov/uas/getting_started/remote_id.

DragonOS tested Remote ID packet broadcast decoding this week and proved the ability for detection and decoding 772m away using a standard 3 dBi omnidirectional stub antenna. The Remote ID transmitter used during the test was Holy Stone’s Drone Remote ID module. DragonOS tunes into these broadcasts using off-the-shelf hardware from ElectronicCats combined with Sniffle software and a Wireshark dissector to decode a drone’s serial number, GPS position, velocity, and GPS position of the ground station. This means that DragonOS will be able to provide its users with real-time situational updates for any drones with Remote ID in nearly a half-mile radius, which is well beyond the range at which anyone could normally see or hear a drone.

RemoteID Detection is coming to the WarDragon soon: https://cemaxecuter.com/?product=dragontooth-remote-id-receiver-kit

Watch Cemaxecuter demonstrate this capability on YouTube:

Capabilities-wise 2G cellular technology is nowhere close to competing with modern 5G implementations, but there are still areas of the world that rely on 2G for communication. YateBTS runs in DragonOS and can emulate a base transceiver station (BTS) on either the BladeRF xA4 or xA9. This week, Cemaxecuter used his BladeRF xA9 as a BTS to make a 6-minute call from a Samsung S4 end-user device (EUD) in the United States to South Africa and Australia. The recent development came thanks to making the switch from session initiation protocol (SIP) to inter-asterisk exchange (IAX) service using DiamondcardUS as the backend service.

Pretty much all US 2G service is gone, but the functionality of YateBTS allows for the BladeRF to act as a BTS and relay a connection from a compatible EUD to DiamondcardUS for international routing. This adds yet another feature to DragonOS that could come in handy. In one of his recent videos, Cemaxecuter was able to join a conference call between himself in Georgia, Rob from Nuand in California, and Rob VK8FOES in Australia. There are some limitations where external users cannot yet dial the EUD on the BladeRF BTS and the BTS cannot directly call cell phone numbers within the US, but it is possible Cemaxecuter could resolve these bugs in the future.

Watch Cemaxecuter use YateBTS on YouTube:

SigDigger is a popular signal analyzer that runs in DragonOS. Pending updates to the panoramic spectrum view feature will allow for seamless spectrum scanning. Thanks to some open-source contributions from sultanqsim the panoramic spectrum feature no longer experiences random lags and unresponsiveness. It’s a bonus for quick spectrum analysis without the headache.

See the pull request here: https://github.com/BatchDrake/SigDigger/pull/245

The Airspy developers are teasing the release of their “Ranger” SDR claiming that it will be an improvement on their HF+ Discovery. Reviewing their specifications, it seems that the Ranger will combine the performance of the HF+ Discovery, R2, and SpyVerter to enable a scan range from 0.5 kHz to 1.75 GHz, a sample rate of 36 MSPS, and -140 dBm sensitivity. This will allow users to view a wider portion of the spectrum than both the R2 and HF+ Discovery without sacrificing the ability to analyze weak signals in all available bands. While it is feasible for users to connect a SpyVerter to the R2 to extend range into the HF band, this extension sacrifices frequency range for sensitivity and adds some connection loss. AirSpy does not advertise the cost of the Ranger, but the HF+ Discovery costs $169 so you should assume it will cost at least as much. Based on their other offerings, it is not likely that the SDR will cost more than $400 given the HF+ Discovery and R2 contain many of the same components.

The Airspy R2 is currently the core default SDR within the WarDragon. For those who are not aware, the WarDragon is the hardware extension to DragonOS’ stellar software suite. Where DragonOS itself makes SDR tools easy to use and access, the WarDragon gives you the hardware you need to play with these tools right away. Cemaxecuter has been pouring improvements into the platform since the first one was sold in early 2024. After selling over 20 WarDragons, his contributions are still going strong. If the Ranger truly expands the available frequency range at no cost to performance, it would be a good opportunity to expand the WarDragon’s frequency range down into the HF band.

Airspy’s Ranger product page is here: https://airspy.com/airspy-ranger/

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