Outdoor access points in ETSI-domain : 5Ghz - DFS channels only?

[MarcelTempelman]

Hi all,

Maybe I have overlooked some documentation but can anyone tell me if the MR74/MR84 access points use DFS--channles only (ch. 100+) in the ETSI-domain (Europe)? I know that the Cisco outdoor APs are limited to DFS-channels.

With kind regards,

Marcel.

[Uberseehandel]

The last time I revised my notes, I recorded - 

• Band A UNI-1 Lower, and Band A UNI-2 Middle were for indoor use only.
• Band A UNI-2 Middle use requires that DFS/TPC/CAC are enabled.
• Band B UNI-2 Extended frequencies are shared with weather radar.
• Band C UNI-3 Upper was originally intended for licensed FPTP outdoor use; in some jurisdictions it has been made available for WiFi Access Points.

[MarcelTempelman]

You're right about the regulations but I wondered if the outdoor APs are limited like the outdoor APs from Cisco (1500-series). These cannot use the UNII-1 and 2 bands which is a bit odd considering the fact the indoor AP can be used on every allowed frequency and you can use them outdoor with an enclosure (you would have to disable the lower UNII bands). 

The reason I'm asking this is that the outdoor AP's are suitable for indiir use where the enviroment is harsh (heat/cold/etc.) but that would automatically mean you would have to use DFS-channels. So for a VoWLAN design these are not the first choice, then I'd rather use an external antenna on an indoor AP in an enclosure.

[Uberseehandel]

As you say,  the indoor AP can be used on every allowed frequency, however, any use of Band A Uni-2 Middle or Band B or Band C requires that DFS/TPC/CAC be active, whether used indoors or outdoors.

As somebody who regularly used to fly in wind shear conditions, I would be more than concerned if equipment were available which allowed users to configure it in contravention of the regulations. One of weather radar's functions is to detect wind shear. Wind shear isn't just another hazard, it can induce fatal outcomes, even on large commercial aircraft.

Maximum power usage in the non-DFS requiring portion of the spectrum is limited to 200 mW (23dBm), which may have a bearing on antenna choice.

[Nash]

@MarcelTempelman Meraki does a couple different things to ensure that your APs are assigned to the correct regulatory domain.

This article discusses it, and provides best practices for managing wireless networks in multiple domain. The biggy being, separate networks for separate domains!

If you need to specifically disable DFS, try the instructions here.

[BrechtSchamp]

I've never read anything suggesting that the outdoor models would support a different channel set than the indoor ones, so I don't think that that is the case. The bands mentioned in the datasheets of for example MR74 and MR42 are identical too.

[Uberseehandel]

Regardless of any perceived need to disable DFS, please do not do so. The consequences of doing so can be fatal. If you do not wish to use channels that require DFS, then stick to  Band A UNI-1 Lower, indoor use only. Some regulators permit the use of Band C UNI-3 Upper by WIFi APs, but usually still require that DFS/TPC/CAC be active.

[Nash]

@Uberseehandel As per the article I linked, when we "disable DFS", we're disabling the ability of the Meraki AP to broadcast on those channels. We're not having any impact whatsoever on anything else.

[MarcelTempelman]

There are a few scenarios where you want to avoid DFS-channels (VoWLAN designs for example), not disable them. In that case you might want to avoid the Cisco 1500-series because these are DFS-only and you might want to ruggedize an indoor AP (E.g. AP in an IP65 enclosure with heating). The fact is that outdoor APs have nice ruggedized features out of the box which make them interesting for harsh indoor enviroments (cold/heat/humidity). The lack of non-DFS-channel support on the 1500-series got me wondering if the Meraki outdoor APs also followed this 'design'. 

[Nash]

@MarcelTempelman We absolutely use the outdoor APs in harsh "indoor" environments. Poorly HVACed warehouse that's 110-120F in the summer, -15F in the winter? Yeeeep, that's an outdoor AP for days. 

Doesn't stop people from accidentally selling indoor APs first, of course... sigh.