Meshtastic, MeshCore, and the Legal Framework

Airtime is only one part of compliance.

Meshtastic and MeshCore are interesting technologies. That is not the problem. They make low-power LoRa communication accessible, inexpensive, and attractive for hikers, makers, emergency-preparedness groups, telemetry projects and radio amateurs.

The problem starts when people forget one simple rule:

That distinction matters. Meshtastic and MeshCore can be used responsibly, but only when the correct legal framework is understood before the first packet goes on air.

868 MHz Is SRD Spectrum, Not Ham Spectrum

In Europe, the commonly used 868/869 MHz LoRa range is normally part of licence-exempt Short Range Device spectrum. That means operation is allowed only inside the defined SRD limits: correct frequency range, allowed radiated power, duty cycle or spectrum-access method, bandwidth, emissions, antenna configuration, and compliant equipment.

That is very different from amateur radio.

If you operate in SRD spectrum, you are operating under SRD rules. Your amateur licence does not add amateur privileges to 868 MHz. A callsign in a packet does not transform the transmission into amateur-radio operation.

The 10% Limit in Meshtastic Is a Compliance Guardrail

Meshtastic’s 10% duty-cycle behaviour is often misunderstood. It is not just a performance setting. It is the software trying to make the node fit the European SRD framework.

When a Meshtastic node reaches its airtime limit, transmission may be delayed or stopped. That can be annoying for users who expect an always-available messaging system, but the reason is important: the software is trying to avoid excessive channel occupation.

But this is only the software layer.

Meshtastic can limit airtime. It cannot prove that the board is CE compliant, that the antenna configuration is allowed, that the radiated power is correct, that the RF output is clean, or that the complete installation still matches the conditions under which the device was placed on the market.

A Meshtastic node that respects 10% airtime can still be non-compliant if the hardware, antenna, power level, filtering, firmware configuration or emissions are wrong.

MeshCore Starts from a More Dangerous Default

MeshCore deserves even more attention in this discussion. In several configurations and examples, MeshCore is used with a much higher airtime allowance than the normal European SRD 10% framework would permit. A commonly seen default or example value is 50% airtime.

For European 868/869 MHz SRD operation, 50% is not a safe starting point. It may be useful in a lab, in a different regulatory environment, or on a properly authorised amateur allocation, but it does not fit the normal 868 MHz SRD framework.

Important: this does not mean “MeshCore is illegal everywhere.” It means that a MeshCore node used unchanged on EU 868 MHz SRD spectrum can be non-compliant from the software side before we even start talking about the hardware.

The first responsible MeshCore step on 868 MHz is therefore not:

How far can we get?

The first responsible question is:

Airtime Is Not the Whole Legal Framework

This is the part many hobby discussions skip. The legal framework is not only about airtime.

A compliant SRD station is not just firmware with a 10% timer. It is the complete radio product or installation as used on air.

• frequency;
• modulation and bandwidth;
• conducted output power;
• antenna gain;
• feedline and connector losses;
• final ERP or EIRP;
• duty cycle or spectrum-access method;
• firmware configuration;
• enclosure and power supply;
• EMC behaviour;
• harmonics and spurious emissions;
• intended use and installation environment.

That is why “the board has CE” is not enough. A CE document for a module or development board may not cover the finished station, the antenna, the firmware, the outdoor enclosure, the high-site installation, the power amplifier, or the way the device is actually used.

The Hardware Trap: 30 dBm Modules, Antennas and ERP

High-power LoRa hardware makes the problem very easy to create. Many modules in circulation are advertised with the capability of 30 dBm output power, or about 1 watt. Some modules go even higher.

That does not automatically mean they may be used at that power level in European SRD spectrum. It only means the chip or module is technically capable of producing that power.

For normal European 868 MHz SRD use, 30 dBm conducted output is already the wrong starting point. The radiated-power limits are strict, and once antenna gain is included, a 1 watt LoRa module will not remain within the usual allowed ERP/EIRP limits.

Now add an external antenna.

That is not a subtle edge case. That is simply too much radiated power for normal European 868 MHz SRD use.

With a 33 dBm, 2 watt module, the situation becomes worse.

This is the classic amateur-radio instinct in the wrong framework. Better antennas, low-loss feedline and high sites are good radio engineering. But in SRD spectrum, antenna gain is part of the radiated-power calculation. A collinear antenna is not free gain. It can make the link better, but it can also make the station non-compliant.

Filtering and Harmonics Are Not Optional Details

The next trap is RF cleanliness. Many LoRa boards are development boards or modules, not complete certified outdoor radio stations. Some are designed for short antennas, modest power and embedded use. When users add higher power, external antennas, mast-mounted installations or poor antenna matching, unwanted emissions become much more important.

If the transmitter chain lacks adequate filtering, or if a PA is driven hard, harmonics and spurious emissions can become a real problem. A small handheld node with a short antenna may hide marginal RF behaviour. A 1 watt module with an outdoor antenna does not.

This is also why a simple “it works over many kilometres” success story can be misleading. Long range may be the result of a good site and good antenna, but it may also be the result of too much radiated power, excessive airtime, poor filtering, or a combination of all three.

The CE Problem Cannot Be Waved Away

For ordinary SRD use, the equipment must be compliant radio equipment. That normally means proper CE marking, an EU Declaration of Conformity for the exact product, correct instructions, known operating conditions and a defined antenna configuration.

A vague test report, an FCC document, a CE-looking logo, or a certificate for a different module is not enough.

Before using a LoRa device as an SRD transmitter, check at least:

• the exact product model;
• the exact frequency band;
• the EU Declaration of Conformity;
• the allowed antenna configuration;
• the maximum power setting;
• the firmware and operating mode;
• the documentation supplied to the end user;
• the importer or manufacturer responsible for EU compliance;
• whether your modifications break the original conformity.

This is especially important when equipment is bought directly from outside the EU. Importing a board yourself can make you part of the compliance chain. “I only bought one” does not make the radio rules disappear.

Why This Is the Danger Zone for Radio Amateurs

For non-hams, the situation is simple: 868 MHz use is SRD use. The device must be compliant SRD equipment and must remain inside the allowed limits.

For radio amateurs, the trap is more subtle. We are used to experimenting. We are used to improving antennas. We are used to building stations. We are used to asking what is technically possible. That mindset is valuable, but it becomes dangerous when it is applied to licence-exempt SRD spectrum as if it were an amateur band.

A callsign in a packet does not turn 868 MHz into amateur radio. A ham operator using 868 MHz is still using SRD spectrum unless there is another specific authorisation.

The dangerous assumption: “It is radio, and I am a ham, so this is ham radio.”

The safer assumption: “Every transmitted packet belongs to a legal framework, and I must know which framework applies before transmitting.”

The risk is not only personal. If radio amateurs start building high-site 868 MHz infrastructure with non-compliant hardware, excessive airtime, high-gain antennas and poor filtering, we create a visible problem in shared spectrum.

That spectrum is used by many SRD and IoT systems. In Belgium and neighbouring countries, 868 MHz is relevant for LoRaWAN, Sigfox and other utility or commercial telemetry systems. If complaints follow, the amateur-radio community will not be able to claim ignorance.

70 cm Is the Cleaner Amateur Route, But Not a Free-for-All

For real amateur experimentation, the cleaner path is to move the project into an amateur allocation where national rules and band planning allow it.

That does not mean “just pick a random 70 cm frequency.” The 70 cm band is shared, structured and already used. A responsible digital network must avoid weak-signal segments, satellite segments, repeater inputs and outputs, calling frequencies, existing digital channels and local usage.

Amateur operation also brings amateur obligations: station identification, station control, non-commercial traffic, respect for licence class, and no private encrypted messaging where prohibited.

So the choice is not “868 MHz or chaos.” The choice is:

A Practical Checklist Before Going On Air

Before transmitting with Meshtastic or MeshCore on 868 MHz, ask:

Meshtastic-Specific Notes

Meshtastic’s 10% airtime limitation is a useful guardrail for European SRD operation. Do not disable it casually. If you need to disable it to make the network usable, that is a sign that the chosen network model may not fit the SRD framework.

Also remember that Meshtastic metadata can still reveal a lot. Even when message content is encrypted, node information, positions, roles, telemetry, traffic timing and mapping integrations can expose more than users expect.

For radio amateurs, encryption is an additional concern. Amateur radio is not a private encrypted messaging service. If Meshtastic is moved to amateur spectrum, the configuration must respect amateur-radio rules, not SRD assumptions.

MeshCore-Specific Notes

MeshCore is technically interesting, but it can be even more dangerous from a compliance perspective when copied blindly from online examples.

If a MeshCore configuration starts at 50% airtime, it is already outside the normal 10% SRD framework for the commonly used European 868/869 MHz sub-band. That makes the problem visible from the software side before the hardware is even considered.

MeshCore may be a better candidate for coordinated amateur experimentation, but then it should be moved into a suitable amateur allocation, with appropriate frequency coordination, station identification, power control and no prohibited private encryption.

The Real Conclusion

Meshtastic and MeshCore are not the problem. LoRa is not the problem. Mesh networking is not the problem. Experimentation is not the problem.

The problem is mixing incompatible assumptions.

Meshtastic’s 10% airtime limit is the software trying to fit the European SRD framework. It does not make unknown hardware legal. It does not validate the antenna. It does not measure harmonics. It does not certify the complete installation.

MeshCore is even riskier when used carelessly on 868 MHz, because a 50% airtime configuration does not fit the usual European SRD 10% framework.

High-power LoRa modules, high-gain antennas, missing or inadequate filtering, detachable antenna systems, vague CE paperwork and high-site infrastructure can turn an interesting project into a non-compliant transmitter very quickly.

So yes: Meshtastic and MeshCore are interesting technologies. But for hams in Europe, 868 MHz is the danger zone. If the network only works by disabling airtime limits, ignoring CE questions, adding gain, increasing power and hoping no one measures the emissions, then the network does not fit the SRD framework.

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