Meraki AP 5ghz transmit power

Faffer · 7 Jun 2019 at 09:59

Hi,

We have a number of Meraki MR42 APs. I have set the 2.4ghz target power to 13dbm and the 5ghz to 20dbm. I am getting 13dbm transmit power on 2.4ghz, but only 17dbm on 5ghz.

RF profile is set to AutoPower min and max 13dbm on 2.4ghz and 20dbm on 5ghz.

Anyone know how to get 20dbm transmit power on 5ghz?

Thanks

Steveocee · 7 Jun 2019 at 12:35

Faffer said:
Hi,
We have a number of Meraki MR42 APs. I have set the 2.4ghz target power to 13dbm and the 5ghz to 20dbm. I am getting 13dbm transmit power on 2.4ghz, but only 17dbm on 5ghz.
RF profile is set to AutoPower min and max 13dbm on 2.4ghz and 20dbm on 5ghz.
Anyone know how to get 20dbm transmit power on 5ghz?
Thanks

That is purely Tx from the unit itself. The unit is most likely self limiting to 23dB EIRP which would account for a 5.5dB gain antenna which a quick google suggested they have.

So to answer you, you can't operate it any higher than you are due to OFCOM rulings.

Faffer · 7 Jun 2019 at 13:01

OK thanks. I'm a relative noob to this mesh wifi stuff. I read that 5ghz transmit power should be around 6dbm+ higher than 2.4ghz so devices would give the 5ghz preference, and I didn't really want to lower the 2.4ghz transmit power any further.

GhostlyPea · 7 Jun 2019 at 15:32

If you want 5GHz preference, enable the WiFi Steering feature for Meraki, it will push clients to 5GHz over 2.4GHz

Handy link:

https://documentation.meraki.com/MR/Radio_Settings/Band_Steering_Overview

- GP

Caged · 9 Jun 2019 at 00:46

Clients should self-select for 5GHz if the conditions are right. Cranking the Tx power up on an AP without knowing the RF environment you’re operating in is not going to be the magical fix for anything.

Faffer · 10 Jun 2019 at 12:45

Thanks for the pointers.

Just tried enabling band steering and users were reporting flaky wifi performance and drops, so reverted it back for now.

GhostlyPea · 10 Jun 2019 at 14:46

Chances are the locations need better coverage fro the 5GHz in that case - did you do a survey? If not try downloading the free version of Ekaau and do a quick heat map fo the area.

- GP

Faffer · 21 Jun 2019 at 16:11

Turns out the signal strength is pretty poor in the office, possibly due to the sheer number of SSIDs and access points in the vicinity. The office is on the first floor, directly above a busy high street tube station in Central London. I'm sitting about 3m away from the closest AP and getting around -67dBm on 2.4Ghz and -77dBm on 5Ghz, so probably not enough 5Ghz coverage for band steering. We have an AP roughly every 15-20m in the office.

Any suggestions, other than doubling the number of APs (and would that even help)?

Thanks

GhostlyPea · 21 Jun 2019 at 16:25

Generally the best thing with wireless coverage is lots of APs with non overlapping cells on lower transmit powers to create a honeycomb effect of signal tessellation. If wireless is important enough for your business then I'd recommend getting a survey from a 3rd party. They will do a good job usually and take most of the guess work out of it which is a huge time saver in the long run. Do the basics like check to ensure they are mounted correctly based upon the antenna type and that they aren't inside a Faraday cage type environment or loads of glass/concrete walls. You can use tools like Ehakau to do it yourself if you pay but there is a free option with some of the basics I would recommend

https://www.ekahau.com/

- GP