High density wireless

[nstr1]

I work in a school, with high user density, and there are several buildings.

With two WLCs;

-WLC 5520 v8.10 (in this WLC its access points are 3802E, 2702E and 9130AXI), with approximately 8000 users.

-WLC 9800-40-k9 v17.9.4 (in this WLC its access points are 9130AXI), with approximately 2000 users.

At some point the entire WLC 5520 will be migrated to the WLC 9800.

building with two floors

Carry out a survey and in some cases it is necessary to reinforce the signal in the corners, which would be carried out with the installation of new access points. On some occasions I have seen my APs with up to 100 users, also carry out best practices.

The question is, do you recommend using the same AP 9130 model or should I use some other model? Or in general is there any recommendation for my high density scheme???

[Jerome BERTHIER]

Hi

High density design is a specific infrastructure use case where you need to take care of a lot of things.

Your design will not only depend on number of users but also of expected throuput, latency and jitter for their usage.

High density design guide : https://www.cisco.com/c/en/us/td/docs/wireless/controller/technotes/8-7/b_wireless_high_client_density_design_guide.html

Short story :

- create smaller cell size with more APs by reducing TX power and/or using directionnal antennas to avoid co-channel interference

- if possible, avoid using 2.4Ghz

- use at most 5Ghz channels as you can depending of DFS, channel interference... Set it in DCA.

- you may keep 20Mhz channel width depending of the density

- use higher data rates

- limit the number of SSIDs

- use 802.11k and 802.11r (802.11v may help or not)

For 9800 controllers, you'll have to split site tags to load balance APs on WNCD threads depending of the platform : https://www.cisco.com/c/en/us/products/collateral/wireless/catalyst-9800-series-wireless-controllers/guide-c07-743627.html#Designingwithsitetagsinmind

I would recommend Cisco Live session BRKEWN-2087 "High Density Wi-Fi Design, Deployment, and Optimization".

About AP model, it depends of what you need to cover and if you plan to move or not others APs.

Take care of RF and mobility parameters between 9800 and 5520 controllers. Keeping APs grouped by roaming domain on the same controller is a better choice :

https://www.cisco.com/c/en/us/td/docs/wireless/controller/technotes/8-8/b_C9800_rrm_dg.html

[jagan.chowdam]

• Cisco 9130 Access Point: For high-density environments like schools, the Cisco 9130 access point is a strong choice. This model can be leveraged in Tri-radio mode, effectively doubling the number of 5 GHz client connections supported by the AP.

• In-Classroom vs. In-Hallway: It's generally preferable to position access points (APs) inside classrooms rather than hallways. Walls can be used to create well-defined coverage areas for each AP, preventing excessive overlap and signal interference. Conversely, placing APs in hallways can lead to them detecting each other's signals and reducing their transmission power. This can negatively impact the actual Wi-Fi coverage within classrooms.

I refer this video every time someone ask me to position an AP in hallway. 

Jagan Chowdam

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