What if radio amateurs had their own data network — independent of the internet, independent of commercial providers, operating on amateur radio frequencies with data rates of up to 200 Mbit/s on backbone links? That’s exactly what HAMNET is: the Amateurradio Multimedia Network. And Austria plays a key role in this development, because the network was invented here.
What is HAMNET?
HAMNET stands for Amateurradio Multimedia Network and is an IP-based data network operating on amateur radio bands — accessible to anyone with an amateur radio licence. It is a self-contained network, completely independent of commercial internet infrastructure. Data rates range from 6 to 200 Mbit/s depending on configuration — enough for VoIP telephony, video transmission, web servers and numerous other services.
Today, over 4,000 nodes are active in HAMNET across Europe. The network extends from Scandinavia to Southern Europe and from Portugal to Eastern Europe. Each node is a radio site — typically on mountain peaks, radio towers or rooftops — connected to neighbouring nodes via directional radio links. This creates a meshed backbone network similar in structure to the commercial internet, but operated exclusively by radio amateurs.
History: From ALAN to HAMNET
The history of HAMNET begins in Austria. In 2005, dedicated radio amateurs in Salzburg started the project ALAN (Amateur Local Area Network). Among the founders were OE2AIP, OE2WAO and OE6RKE, who drove the vision of a broadband amateur radio network.
The first operational link connected OE2XZR on the Gaisberg near Salzburg with OE2XGR on the Gernkogel — a distance of about 56 kilometres. This successful test proved that the technology worked and high data rates over long distances were possible.
In 2008, the project was renamed HAMNET to emphasise its international character. From 2009, the Austria-wide expansion followed. OE7BKH and OE7FMI implemented BGP routing (Border Gateway Protocol) for the Tyrolean network, which became the model for the entire network architecture. Today, HAMNET is the largest non-commercial radio network in Europe.
HAMNET Explained: Presentation by OE1KBC
Kurt Baumann (OE1KBC), one of the driving forces behind Austrian HAMNET, explains in this presentation what HAMNET is, how it works and who can participate:
The Technology Behind HAMNET
HAMNET uses modified WLAN technology on amateur radio frequencies. The backbone network operates in the 5 GHz range (5.6 to 5.8 GHz), while user access is provided on 2.4 GHz and 5 GHz. The radio technology is based on the IEEE 802.11a/n standard, adapted for amateur radio frequency ranges.
Key technical features:
- Channel bandwidths: 5, 10 or 20 MHz — depending on available spectrum and required data rate
- Routing: BGPv4 (Border Gateway Protocol Version 4) for automatic path finding
- Line of sight: Working in the GHz range requires a direct line of sight between stations
- Polarisation: Horizontal polarisation is standard to minimise interference from commercial WLANs
- SSID: Uniformly “HAMNET” — making the network easily identifiable
- Data rates: Typically 6 to 20 Mbit/s on user access, up to 200 Mbit/s on backbone links with 802.11n and MIMO antennas
Infrastructure in Austria
Austria has one of the best-developed HAMNET networks in Europe. The network is organised in four zones: East, North, West and South. All nine federal states are connected, with nodes positioned at strategically important elevations.
Key locations include:
- OE1XAR Bisamberg (Vienna) — central node for Eastern Austria
- OE1XUU Kahlenberg (Vienna) — additional backbone node in the Vienna area
- OE2XZR Gaisberg (Salzburg) — historic site, part of the first HAMNET link
- OE7XLR Seegrube (Innsbruck) — key node for Tyrol and the western connection
- OE8XDR Dobratsch (Carinthia) — important southern node with backbone links to Sonnblick (OE2XSR) and Gerlitze (OE8XGR), user access on 2.427 GHz
The entire network structure is viewable on the interactive map at hamnetdb.net, where you can look up every node, every link and the associated technical data.
Services on HAMNET
HAMNET is far more than just a data network — it offers a wide range of services that enrich amateur radio:
- Mumble VoIP: Voice communication over the network — similar to Teamspeak, but for radio amateurs
- HAMSIP Telephony: Real SIP-based VoIP telephony over HAMNET — with its own numbering plan based on callsigns. Register at hamweb.at, get a number and call other radio amateurs with any SIP-capable device (IP phone, smartphone app, FritzBox). The connection runs via distributed Asterisk servers across Austria. More in our HAMSIP article
- APRS Server: Position data and telemetry via HAMNET instead of the internet
- DX Cluster: Real-time DX spots directly over the amateur radio network
- Packet Radio: Classic packet radio services at significantly higher speeds than on UHF
- Winlink Gateway: Email access via HAMNET without an internet connection
- Repeater Linking: D-STAR, DMR and C4FM repeaters are networked via HAMNET
- Meshtastic/MeshCom Gateway: Bridge between LoRa mesh networks and HAMNET
- Digital ATV: Amateur television in digital quality over the broadband network
HAMNET in Action: GAB Austria Presentation
At the GAB Austria meeting, HAMNET was presented as the “Internet of Radio Amateurs” — with insights into Austrian infrastructure and practical applications:
IP Addressing and DNS
HAMNET uses the AMPRNet address space 44.0.0.0/8, allocated to amateur radio worldwide. Austria has the range 44.143.0.0/16, with each OE region receiving its own subnet and AS number (Autonomous System, range 64512–64599).
DNS naming follows a uniform scheme: devicename.location.hamnet.radio. For example, a web server on the Gaisberg is reachable at web.oe2xzr.hamnet.radio. This system enables clean structuring and easy discoverability of all network components.
Through the use of BGP routing and standardised IP addresses, HAMNET is fully compatible with all common network protocols and applications. Any device that speaks TCP/IP can operate on HAMNET.
Getting Started: How to Access HAMNET
Getting into HAMNET requires some planning but is neither particularly expensive nor overly complicated. The key steps:
1. Check coverage: Look on hamnetdb.net to see if a HAMNET node is within range. The map shows all active nodes and their beam directions.
2. Verify line of sight: Since HAMNET operates in the GHz range, a clear line of sight to the nearest node is required. Tools like HeyWhatsThat or Google Earth help with verification.
3. Get equipment: The most common devices for user access are:
- Ubiquiti NanoBeam 5AC: Compact directional antenna with integrated router, approx. EUR 90–110
- Mikrotik SXTsq 5 ac: Small, powerful flat antenna, approx. EUR 70
Both devices are powered via PoE (Power over Ethernet) — a single network cable handles both data and power. Total costs for user access typically range from EUR 90–300, depending on the chosen antenna and any required accessories such as mast mounts or weatherproof enclosures.
4. Connect: Most HAMNET access nodes assign IP addresses automatically via DHCP — just like a regular Wi-Fi router. You connect, receive an address from the 44.143.x.x range and are immediately on the network. Manual IP registration is only needed if you want to run your own services or set up a node.
5. Align and go: Point the antenna at the nearest HAMNET node and set horizontal polarisation. Once connected, the entire HAMNET network with all its services is at your disposal.
No Node in Sight? No Problem: VPN Access
The biggest hurdle for HAMNET access is line of sight: if you don’t have a node within direct radio range — perhaps in a valley, behind a mountain, or in a flat without the option to install an antenna — you can still use the network. The solution: VPN access via the internet.
An encrypted tunnel is established from your PC or router via the internet to a HAMNET gateway. Once connected, your computer behaves as if it were directly connected to HAMNET via radio — all services, all nodes, all applications are accessible.
How VPN Access Works
- Register: Sign up at hamweb.at with your callsign. Your amateur radio licence is verified — for example with a photo of your licence certificate. Alternatively, institutions in Germany (e.g. RWTH Aachen) also offer VPN access.
- Set up VPN client: Login credentials are sent by email. Depending on the provider, PPTP, L2TP or IKEv2/IPSec are used as protocols. Configuration takes just a few minutes — on PC, smartphone or directly on your router (e.g. FritzBox or OpenWRT).
- Connect and go: After establishing the VPN tunnel, traffic to the HAMNET address range (44.0.0.0/8) is automatically routed through the tunnel. Regular internet traffic continues via your normal provider.
VPN access is particularly valuable for using HAMNET services like HAMSIP telephony, DX Cluster, APRS and web servers without installing any RF hardware. It’s also ideal for getting to know the network — you can explore at your leisure and decide whether investing in your own antenna is worthwhile.
Important: VPN access does not replace RF access. HAMNET’s real strength lies in its independence from the internet. A VPN tunnel is only as reliable as the internet connection it runs over. In an emergency — during a blackout or internet outage — only genuine radio access works.
Emergency Communications and Blackout Resilience
One of the most important aspects of HAMNET is its independence from commercial infrastructure. While the internet depends on fibre optic networks, data centres and power supplies that can fail during a large-scale blackout, HAMNET can in principle continue to operate — provided the nodes are equipped with backup power.
HAMNET’s blackout resilience depends entirely on the backup power supply at each individual node. Whether a site continues to operate during a prolonged power outage depends on whether UPS systems, batteries, solar panels or generators are installed there. Current emergency communications projects are working to systematically expand this capability.
In Lower Austria, the Notfunk NÖ 2025 project has been running since 2025, networking municipalities and district authorities via HAMNET. The goal is to maintain a functional data connection between authorities in the event of a total failure of commercial communications. The three-tier fallback concept provides for:
- Tier 1 — HAMNET: High-speed data connection via the existing network
- Tier 2 — Radio backup: Classic amateur radio via HF and VHF as a fallback
- Tier 3 — QO-100 Satellite: Communication via the geostationary amateur radio satellite as a last resort
The A.R.E.N.A. (Amateur Radio Emergency Network Austria) project has also designated HAMNET as the communication backbone for disaster scenarios. Emergency exercises take place in individual federal states, demonstrating that the technology fundamentally works — the nationwide expansion of backup power remains an ongoing task.
WRAN: The Future of HAMNET
The biggest limitation of HAMNET is the requirement for line of sight. In valleys, behind mountains or in densely built-up areas, access is often difficult or impossible. This is where the future project WRAN (Wireless Regional Area Network) comes in.
WRAN is based on the IEEE 802.22 standard, also known as “Super WiFi”. This technology uses lower frequencies and can therefore work without line of sight — signals penetrate forests and diffract around terrain features. A single WRAN access point can reach distances of 20 to 30 kilometres.
Hardware development was started under the name RPX-100 and funded through a grant from ARDC (Amateur Radio Digital Communications). Once WRAN becomes widely available, the “last mile” — the connection from the HAMNET backbone to the individual radio amateur — will be significantly easier to achieve.
HAMNET Compared to the Internet
HAMNET and the commercial internet have different strengths and use cases. A comparison:
Advantages of HAMNET:
- Independence: No commercial provider, no monthly costs, no dependence on fibre optic infrastructure
- Free of charge: Operation is free for licensed radio amateurs — only the hardware needs to be purchased once
- Exclusivity: Only accessible to licensed radio amateurs — no spam, no advertising, no mass usage
- Crisis resilience: Can continue operating during power and internet outages — but requires nodes to be equipped with backup power
- Learning effect: Building and operating the network provides deep knowledge of networking, RF technology and IT
Limitations of HAMNET:
- Line of sight: In the GHz range, a clear line of sight to the nearest node is required
- Data rates: Typically 6–20 Mbit/s for user access — sufficient for most applications, but no replacement for fibre
- No internet gateway: HAMNET is a closed network — a transition to the commercial internet is not intended for legal reasons
- Licence required: Only holders of a valid amateur radio licence may use HAMNET
HAMNET is not a replacement for the internet, but a complement — a self-contained network that proves its value especially when everything else fails. At the same time, it is a fascinating experimental field for anyone interested in networking, radio propagation and building critical infrastructure.
If you’re interested in HAMNET, you’ll find the current network overview at hamnetdb.net. At hamweb.at you can register for VPN access and HAMSIP telephony. The HAMNET community in Austria is active and helpful — new nodes and users are always welcome. If you don’t have a licence yet: Getting started is easier than you think.
73 – your oeradio.at editorial team
Sources and Further Reading
- hamnetdb.net — Interactive map of all HAMNET nodes and links in Europe
- ÖVSV Wiki: User Access HAMNET — All access nodes in Austria (OE1–OE9) with frequencies and antenna types
- ÖVSV Wiki: Applications on HAMNET — Complete service list (APRS, VoIP, DX Cluster, ATV, Packet Radio)
- ÖVSV Wiki: VoIP – HAMSIP — Technical documentation on SIP telephony in HAMNET
- hamweb.at — Registration for VPN access and HAMSIP telephony
- RWTH Aachen: VPN Access to HAMNET — Alternative VPN access with guide
- DL1NUX: Setting up HAMNET access with Mikrotik — Step-by-step hardware configuration guide
- Wikipedia: HAMNET — Overview article with history and technical fundamentals
- ARDC Grant: WRAN for HAMNET — Funding project for RPX-100 “last mile” technology
Transparency Notice
This article was researched and written with the assistance of AI (Claude, Anthropic). The editorial team has reviewed and edited all content. Despite careful review, occasional inaccuracies may be present — we welcome feedback via email to [email protected].
