IP400, a new amateur radio mesh network on the horizon

The IP400 project is a new amateur radio development aimed at bringing a high-speed mesh networking system to the 400 MHz band. Its core idea is to combine modern, IP-based networking concepts with spectrum that is traditionally well suited for wide-area coverage, good building penetration, and mobile operation.

Instead of treating radio purely as a medium for analog voice or narrowly scoped digital modes, IP400 approaches radio as a general-purpose IP transport layer, optimized for constrained bandwidth, shared spectrum, and real-world RF conditions. The result is a mesh-oriented architecture designed specifically for amateur experimentation rather than commercial deployment.

The project is coordinated by the Alberta Digital Radio Society and follows a strictly non-commercial, experimental philosophy. There is no vendor lock-in, no closed ecosystem, and no finalized standard. IP400 is best described as a developing platform and technical direction rather than a finished product.

A focus on the 400 MHz band

One of the defining characteristics of IP400 is its focus on the 400 MHz region, which occupies a unique position between VHF and UHF. This band offers a favorable balance of range, diffraction, and antenna size, making it attractive for wide-area mesh networking compared to microwave-based solutions.

Unlike amateur mesh systems that rely on repurposed Wi-Fi hardware and wide bandwidths, IP400 is designed from the ground up for lower symbol rates, longer reach, and better spectral efficiency, making it suitable for mobile, portable, and semi-fixed installations.

Technology foundation and early research phase

The initial phase of the IP400 project focused on evaluating modern off-the-shelf radio components designed for IEEE 802.15.4 operation in the 400 MHz band. These components, originally intended for industrial and IoT applications, offer robust modulation schemes, low power consumption, and efficient packet handling.

An evaluation board supplied by the manufacturer was used during early development to validate modulation performance, achievable data rates, and mesh behavior under amateur radio conditions. This phase confirmed that the technology was viable and scalable beyond simple sensor-style networking.

Based on these findings, the project moved beyond evaluation into multiple parallel development tracks.

Mini Node: low power mesh entry point

The Mini Node is the simplest IP400 network element and serves as an entry point into the mesh. It is a low-power node implemented as a Raspberry Pi Zero HAT, designed to be inexpensive, compact, and easy to deploy.

Despite its simplicity, the Mini Node is capable of joining the IP400 mesh and exchanging IP data at speeds of up to 100 kb/s. This makes it suitable for experimentation, portable use, sensor-style applications, messaging, telemetry, and basic IP services.

The Mini Node establishes the baseline protocol compatibility for the entire IP400 ecosystem.

Power Node: outdoor-capable mesh infrastructure

The Power Node represents the next generation of IP400 hardware. It builds on the Mini Node concept but adds features necessary for permanent or semi-permanent outdoor deployment.

This node includes an integrated power amplifier and is designed to work with a coaxial collinear antenna, improving range and link reliability. It is powered via Power over Ethernet (PoE), simplifying installation on towers, rooftops, and elevated sites.

The Power Node is intended to act as a mesh backbone element, supporting wider coverage and higher node density. It is currently in development, with availability expected in spring 2026.

Super Node: bridging legacy systems and high-speed data

The most ambitious component of the IP400 architecture is the Super Node. This device is designed to enhance and extend aging amateur repeater systems rather than replace them.

In the analog domain, the Super Node is Allstar-compatible, allowing it to integrate seamlessly with existing repeater infrastructure. In parallel, it introduces three distinct data modes:

• A compatibility mode that interoperates directly with Mini Nodes and Power Nodes

• An enhanced data mode designed for mobile or fixed stations, compatible with existing IP applications

• A high-speed OFDM mode intended for point-to-point and point-to-multipoint links

This layered approach allows IP400 to scale from low-speed mesh networking to significantly higher data rates where spectrum conditions and licensing allow. The Super Node is currently under active development and is expected to become available in late 2026.

How IP400 differs from existing amateur mesh networks

Existing amateur radio mesh networks often focus on high-speed microwave links, frequently using modified consumer Wi-Fi hardware. These systems can achieve impressive throughput but are typically limited to line-of-sight paths, wide channels, and relatively fixed installations.

IP400 occupies a different niche. It prioritizes coverage, flexibility, and protocol efficiency over raw bandwidth. By operating in the 400 MHz band and embracing lower data rates, it opens the door to mobile, portable, and mixed-environment mesh deployments that are difficult or impractical with microwave-based systems.

At the same time, IP400 goes beyond traditional packet radio by supporting native IP networking and multi-mode operation within a unified architecture.

Bands, topology, and operating concepts

IP400 networks are expected to support true mesh topologies, where nodes can dynamically route traffic based on link quality and availability. Point-to-point links, local meshes, and regional backbones can coexist within the same system.

While the primary focus is on the 400 MHz band, the architectural concepts are not inherently band-limited. The project explores how IP networking behaves under constrained RF conditions rather than optimizing for a single frequency range.

Why IP400 matters to the amateur community

IP400 reflects the original experimental spirit of amateur radio. It does not aim to replace voice QSOs or established digital modes, nor does it attempt to compete with commercial broadband solutions.

Instead, it provides a living laboratory for exploring how modern networking concepts behave when applied to real radio channels with limited bandwidth, shared access, and variable propagation.

For amateurs with an interest in networking, embedded systems, RF design, or emergency communications, IP400 represents a meaningful step toward a more integrated and future-oriented view of amateur radio.

IP400 is not just another digital mode. It is a statement that amateur radio mesh networking still has unexplored territory—especially outside the high-speed microwave space—and that the 400 MHz band may play a key role in that future.

Image(s) used in this article are either AI-generated or sourced from royalty-free platforms like Pixabay or Pexels.