topic Re: Access Point maximum range and users in Wireless

Access Point maximum range and users

absuizo14 — Fri, 25 Oct 2024 09:59:50 GMT

for some reason our client is adamant about knowing the maximum range of the access points and the maximum amount of users an ap can accommodate. i know there is a computation for theoretical maximum range of the access point using its transmit power, antenna gain and frequency in vacuum but they prefer it explicitly stated on a cisco document or site.

here are the models incase you have any documentation

C9115AXI-A, C9105AXW-A, C9120AXI-A

Re: Access Point maximum range and users

Mark Elsen — Fri, 25 Oct 2024 10:33:53 GMT

- FYI : https://community.cisco.com/t5/wireless/what-is-the-coverage-area-of-any-ap/m-p/2370504/highlight/true#M132863
The maximum amount of users is variable and depends on the wireless data load that they can generate ,

Re: Access Point maximum range and users

Flavio Miranda — Fri, 25 Oct 2024 10:34:49 GMT

@absuizo14

All the information about the AP is on the datasheet. Cisco used to inform the maximum client per rádio in the past but they removed it. You may find this information in resseller document, usually 200 client per rádio but, not cisco oficial. You can open a TAC and ask this and the number will be much less, probably around 15 users. It will depend on the engineer experiency.

Maximum range they never informed and they are correct. Maximum range is totally environmental depedent. What they must inform, and they do, is all the antenna specification. But, you can not put in a document that the range is 100 meters and then the client install the AP inside of a metal box(as I have seeing more than once) and they open a TAC telling the maximum range reached was 10 meters.

You probably already scratched the internet and did not find It and, most probably, you will not. I went through this before.

Re: Access Point maximum range and users

absuizo14 — Fri, 25 Oct 2024 10:50:43 GMT

yeah i know there are a lot of factor affecting the range that is why i stated theoretical and in a vacuum. there is a formula to compute this

where:

( P_t ) is the transmit power in dBm (23 dBm)
( G_t ) is the transmit antenna gain in dBi (4 dBi)
( P_r ) is the receiver sensitivity in dBm (assuming a typical value of -90 dBm for Wi-Fi)

but i doubt they would accept anything not coming from cisco

Re: Access Point maximum range and users

Flavio Miranda — Fri, 25 Oct 2024 11:12:54 GMT

If you can, open a TAC and ask those questions. They will reply to you either with a valeu or with the information that is not possible to set a value and then you can use it as evidence for your customer.

Re: Access Point maximum range and users

Rich R — Mon, 28 Oct 2024 08:07:11 GMT

It is way more complicated than you think. It will depend on:
- Regulatory domain - signal strength (EIRP) is different in different countries
- Antenna - different antenna have different gain
- Channel - different channels have different max EIRP (according to regulatory domain)
- Band - propagation is different for 2.4 and 5 GHz frequencies
- Environment - as Flavio said this is key. Only a site survey can determine theoretical coverage in a specific environment and post-install survey will be needed to confirm.

The data you need for your calculation (pointless in my opinion - just do a professional site survey) can be found at:
https://www.cisco.com/c/en/us/support/ios-nx-os-software/ios-xe-17/products-technical-reference-list.html
For example for 9105AXW-A you'd refer to Detailed Channels and Maximum Power Settings for Cisco Catalyst 9105AXW Indoor Access Points, Release 17.6.1 then use the sheet for your regulatory domain (-A) and the band you want to (2.4 or 5) and then use the data for each channel, channel width etc You'll need to run that calculation hundreds of times for each AP and produce a table with the corresponding results. This would be completely pointless for everyday use case.

Also remember a design which relies on you running the AP at full power (for "maximum range") is likely to be a really bad design.

Check out the Meraki design guide at
https://documentation.meraki.com/Architectures_and_Best_Practices/Cisco_Meraki_Best_Practice_Design/Best_Practice_Design_-_MR_Wireless/High_Density_Wi-Fi_Deployments
which covers a whole lot of the basic principles.