Wi-Fi Outdoor Use (5GHz restrictions)

Hi everyone,

I'm looking into certification requirements for the M404, and I noticed a couple of things in the data sheet regarding the restriction of using 5GHz bands outdoors. Please see below.

Wi-Fi operation in the 5150-5250 MHz band is only for indoor use to reduce the potential for harmful interference to co-channel mobile satellite systems.

Operation in the band 5150โ€“5250 MHz is only for indoor use to reduce the potential for harmful interference to co-channel mobile satellite systems;

Operation in the 5600-5650 MHz band is not allowed in Canada. High-power radars are allocated as primary users (i.e., priority users) of the bands 5250-5350 MHz and 5650-5850 MHz and that these radars could cause interference and/or damage to LE-LAN devices.

Question 1:
How do I control which bands the M404 uses when using Wi-Fi if I want to operate with Wi-Fi outdoors? For context, the M404 would be in a box mounted on the exterior of a building. I'm assuming this also applies to the Photon and P2. I couldn't find any reference in the Device OS API docs for this. Can anyone help with this?

Question 2:
Can someone tell me how to ensure my product is compliant with the following which is also in the M404 datasheet under Outdoor Use (US)? Is this something Particle has already taken care of or would this depend on how the M404 is used?

To be compliant to FCC ยง15.407(a) the EIRP is not allowed to exceed 125 mW (21 dBm) at any elevation angle above 30ยฐ (measured from the horizon) when operated as an outdoor access point in U-NII-1 band, 5.150-5.250 GHz.

Hey Hector,

Assuming you are operating in the USA and using an M404 in Station mode (i.e. end device mode), the primary responsibility for compliance lies with the access points that are serving up the 5GHz based Wi-Fi. This is similar to how Smartphones work - they don't know if they are inside or outside and trust the Access Point to configure itself accordingly.

In general, Access Points that need to comply are those extremely powerful ones found in commercial, education and industrial buildings vs the ones you find in your home. Those in your home are impacted, but with much less restrictions in terms of impact to supported bands.

Saying this, end devices are subject to FCC regulations regarding their overall operation within the 5 GHz spectrum, including limits on their radiated power and requirements for non-interference. Particle has ensured that our M404 has met FCC standards and are compliant with features such as Dynamic Frequency Selection a total transmit power, as mandated by the FCC standard. Accordingly, you can deploy your Wi-Fi Station outside without worrying about additional compliance steps (outside of passing general FCC Part 15 testing).



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Hi Nick,

Thanks for the quick reply! In my application, the M404 will in fact be operating primarily as an end device and not an access point. I'll be operating in both the USA and in Canada.

One thing that came to mind is that in some earlier prototypes that I've built with an ESP8266, I've used the WiFiManager library as a way for a user to input Wi-Fi credentials, and this turn the device into an access point to which a smart phone can connect and input credentials in a form. I don't know if I'm going to do something similar moving forward, but if I did, would I need to worry about compliance here? I'm also not aware of what, if any, APIs or workflows Particle has for inputting credentials.


Hey Hector

We support a BLE based setup approach on the M404 (and Photon 2, P2 and other M-Series based devices) - examples are on our GitHub for iOS, Android and React Native (iOS + Android combined). There is no wireless compliance required when using these applications (outside of FCC Part 15 b testing at the end device side), so no need to worry on this side.