Legal and Regulatory

FCC Part 15 Compliance for LoRa Mesh

Meshtastic and MeshCore operate in the 902-928 MHz ISM band under FCC Part 15 in the United States. This section explains what the rules require, what they allow, and what you need to know for compliant operation.

FCC Part 15 Basics

Part 15 covers unlicensed intentional radiators - devices that deliberately emit radio frequency energy. The key rules for 902-928 MHz spread spectrum:

The 1W + Antenna Gain Calculation

Most LoRa hardware ships configured at or below 1W (30 dBm) conducted power. Note that the 1 W limit under 15.247 applies to digitally-modulated systems whose minimum 6 dB bandwidth is at least 500 kHz; many Meshtastic/MeshCore presets use 125-250 kHz bandwidth, which may be certified under different provisions - so treat 1 W as an upper ceiling, not a guaranteed allowance for every preset. If you add a high-gain external antenna, you must reduce conducted power for any antenna gain above 6 dBi.

Example calculation:

First example:
Antenna gain: +6 dBi (at the 6 dBi threshold - no reduction required)
Conducted power: 30 dBm (1W) - COMPLIANT
(Resulting EIRP works out to about 36 dBm / 4 W, the derived ceiling.)

Second example:
Antenna gain: +9 dBi (3 dB above 6 dBi)
Rule: reduce conducted power by (9 - 6) = 3 dB
Maximum conducted power: 30 - 3 = 27 dBm (500 mW)
Running 30 dBm conducted into a 9 dBi antenna is NON-COMPLIANT.
Note: feedline (cable) loss does NOT offset this 3 dB reduction - the
reduction is based on antenna gain alone.

For typical community deployments with 5-6 dBi antennas and short coax runs, full 1W conducted power is generally compliant (gain is at or below the 6 dBi threshold). With 8-9 dBi antennas, you must reduce conducted power by the dB of gain above 6 dBi - e.g. to 27-28 dBm for a 8-9 dBi antenna.

Point-to-Point Operations (Fixed Infrastructure)

Important: at 902-928 MHz there is no special power allowance for fixed point-to-point links. The relaxed point-to-point rule that some guides cite applies only to other bands:

Pre-Certified Hardware

Reputable mesh hardware sold in the US should carry an FCC ID - check the device label or the FCC ID database. Verify this before deploying: some imported hobbyist dev boards are not properly certified, or carry only module-level certification rather than full device authorization. This certification confirms Part 15 compliance when used with the included antenna and at the specified power levels. Using third-party antennas or modifying conducted power beyond the certified levels may affect compliance status. For community mesh operations, using hardware within its certified parameters is the simplest path to compliance.

What Part 15 Does NOT Require

Operating in Canada: ISED Rules

In Canada, LoRa mesh networking in the 902-928 MHz band operates under Innovation, Science and Economic Development Canada (ISED) regulations, primarily RSS-247 (Digital Transmission Systems, Frequency Hopping Systems and Licence-Exempt LAN Devices) together with RSS-Gen.

Key Canadian Rules

Canadian ISM Band Availability

The 902-928 MHz band is available across Canada for license-exempt operation, making it directly compatible with US equipment and networks. Canadian and US mesh operators using 915 MHz hardware can interoperate seamlessly near the border.

Interference Considerations

Canada shares the 902-928 MHz ISM band with various Part 15 equivalent users. The non-interference and no-protection rules apply equivalently: you must not cause harmful interference, and you have no protection from interference by other users.

Quebec/French Language Considerations

Canada's Official Languages Act applies only to federal institutions and certain federally regulated businesses - it does not cover hobbyist mesh groups or typical nonprofits publishing software documentation. Organizations doing business in Quebec should instead be aware of Quebec's Charter of the French Language. For individual hobbyist operation, no language requirements affect technical operation of mesh networks.

ARES Canada

In Canada, the Amateur Radio Emergency Service (ARES) is organized by Radio Amateurs of Canada (RAC); its volunteers operate on amateur frequencies under their individual ISED (formerly Industry Canada) Amateur Radio Operator Certificates, not under organization-held spectrum licenses. When MeshCore or Meshtastic is used on ISM frequencies (902-928 MHz), ARES volunteers operate under the same license-exempt rules as all other Part 15 equivalent operators - no additional authorization is required.

Operating Outside North America

LoRa mesh hardware designed for North America operates on 902-928 MHz, which is an ISM band in the US and Canada but is not an ISM band in most of the rest of the world. Traveling or deploying internationally requires care.

European Union: 868 MHz

Europe uses 863-870 MHz for LoRa operations, under ETSI EN 300 220 harmonized standards. EU regulations differ from US Part 15:

US hardware (915 MHz) must not be operated in EU countries. If you are deploying in Europe, purchase EU 868 MHz hardware specifically.

Australia and New Zealand

Australia (ACMA) and New Zealand (Radio Spectrum Management) allow LoRa operation on 915-928 MHz under license-exempt rules broadly equivalent to US Part 15. US-band hardware covers the AU/NZ 915-928 MHz range (set region to ANZ), but check that the device carries Australian/NZ RCM compliance marking - FCC certification alone does not authorize sale or use.

Asia-Pacific

Regulations vary significantly by country:

General International Guidance