topic Re: Planning in Wireless

Planning

bluesea2010 — Thu, 14 Apr 2022 07:27:56 GMT

Hi,

When we are preparing for the heatmap what all the factors should be included.

If I am planning an wifi 6 heat map , what is the maximum and minimum power should be selected ?

Thanks

Re: Planning

Flavio Miranda — Thu, 14 Apr 2022 11:20:10 GMT

You should consider the size of the floor, Obstables, Glassess, Concrete, walls, etc.

"If I am planning an wifi 6 heat map , what is the maximum and minimum power should be selected ?"

Well it depends on the noise floor but considering a normal noise floor which -90dBm, I´d consider -65 dBm up to -75 dBm signal. But, the most important is not the power but the SNR. The SNR is the different between Noise Floor and Power. A great value for SNR is something arount 35 dB. But, above 15 dB you are OK.

Re: Planning

balaji.bandi — Thu, 14 Apr 2022 14:05:56 GMT

site survey tool should give you some information.

Re: Planning

bluesea2010 — Fri, 15 Apr 2022 12:30:51 GMT

Hi @Flavio Miranda

My question , when doing heat map what is the maximum power value do I choose to decide the cell size

Thanks

Re: Planning

Flavio Miranda — Fri, 15 Apr 2022 12:46:48 GMT

You are looking from the wrong perspective. You are looking to one linear value and RF does not work like this. And the cell size is entirely dependent of the antenna and you actually see it the Access Point Data sheet

Re: Planning

bluesea2010 — Sun, 17 Apr 2022 11:46:16 GMT

Hi @Flavio Miranda

I have some devices with very low power radios . now the question is if I put 30dbm as the maximum power , the device can hear from the AP but device could not reach the AP .

I want to avoid the above situation

Re: Planning

Flavio Miranda — Sun, 17 Apr 2022 12:16:09 GMT

The power requirements must follow the lower power capacity. As you stated very will, if AP can send signal to device but device does not send back properly, it is wast of time.

When doing the site survey, you need to set your laptop with the power of the weaker device.

Re: Planning

bluesea2010 — Sun, 17 Apr 2022 12:31:15 GMT

Hi @Flavio Miranda

" When doing the site survey, you need to set your laptop with the power of the weaker device."

My question do I need to consider the above when doing heatmap. What should be the value for transmit power

Thanks

Re: Planning

Flavio Miranda — Sun, 17 Apr 2022 12:56:37 GMT

I dont understand completely what you mean by "doing the heatmap". Heatmap the way I see it, is generated by the tool you performed the site survey (Ekahau, Airmagnet,iBwave,etc) or Cisco Prime or Cisco DNAC.

Explain to me how do you "do" the heatmap from your side please

Re: Planning

bluesea2010 — Sun, 17 Apr 2022 17:44:34 GMT

Hi @Flavio Miranda

https://support.ekahau.com/hc/en-us/articles/115005087848-Designing-Wi-Fi-Networks-with-Ekahau-Pro

Below is the last part of the article , it says about the transmit power

If you leave the access point transmit power settings to Automatic Radio Management (Radio Resource Management, Radio Management) from your wireless LAN management software, using the default 25mW transmit power is recommended when creating simulated APs.

Thanks

Re: Planning

Flavio Miranda — Sun, 17 Apr 2022 23:04:19 GMT

Alright! Finally I got you. Sorry for take so long and thank you for being paciente. And yes, that the value we use. I attached a real heatmap I built with Ekahau some times ago.

You are actually reffering to 'Predictive Site Survey". I did this for so many times.

Re: Planning

bluesea2010 — Mon, 18 Apr 2022 05:50:26 GMT

Hi @Flavio Miranda

Thanks for the reply you . What made you to choose the maximum power 25 ? it must be less for low end devices ?

And why you are included 2.4Ghz in a predictive site survey

Thanks

Re: Planning

Manuka Rajapaksha — Mon, 18 Apr 2022 17:31:10 GMT

AP has much better receiver sensitivity than the enpoints. So, you don't need to consider same Tx power both sides.

When you're doing the heatmapping,

Start with the half of your AP's available Tx power. (Keep in mind! values are not linear)
Simulate the users within the tool. (if the option available)
Set your channel plan. (with the required channel-width)
Set your RSSI thresholds (depending on the SNR and the client specs)

Then adjust the Tx power and AP locations until you get the optimum design. And make sure you have the correct airtime level for each AP.