How to force wireless clients to connect to 5Ghz band without "Band Select" feature on Cisco WLC

[g.ska]

Hi everybody,

I think everything is in the title :).

I'm looking for a way to enforce wireless client to connect to 5ghz network (in the case of both 2.4 and 5ghz are configured) without the band select feature that is not recommended when we use "Voice" on wireless. I was thinking to lower the power of the 2.4Ghz wifi (in TPC tab) to force client to connect to the 5Ghz. 

Do you think that it could be a good solution? Do you have any other idea to achieve this goal?

FYI: we have the 8.3.143 version of AireOS on WLC 5508.

Many thanks,

Greg.

[Leo Laohoo]

At the end of the the day, it is the wireless client that makes the ultimate decision which AP to join and which radio to connect to.
The older the wireless driver/firmware loaded into the wireless client, the worst decision it will make.
Also, some wireless client can be configured to choose which radio to use.

[pieterh]

why the need to enable 2.4GHz when you want to force 5GHz?

create one SSID 5GHz only for clients that can use this, no need to switch to 2.4 GHz

create another for clients that do not support 5GHz

use AP groups to enable the second SSID only on a limited number of AP's

[g.ska]

Hi Pieterh,

Thank you for your response. I answered to your question bellow:

why the need to enable 2.4GHz when you want to force 5GHz?

• Because we use old legacy devices that does not support the 5Ghz band

create one SSID 5GHz only for clients that can use this, no need to switch to 2.4 GHz

• It's an option but we want to avoid to create more SSID in our infrastructure to save "airtime"

create another for clients that do not support 5GHz

use AP groups to enable the second SSID only on a limited number of AP's

• The SSID need to be propagated globally (not on limited number of AP's) because the old legacy device (Barcode scanner) need to be connected everywhere in the building for inventory purpose.

Best regards,

Greg.

[pieterh]

then your question to "force" 5GHz connectivity does not describe your problem.

your option is to modify the client device wireless network setting to "prefer" 5GHz where possible, 

you may include this somewhere in the client installation process

or If AD connected you can create a domain policy to push the setting to the clients

[g.ska]

Yes we can do it for laptops managed by AD. But do you think there's a solution for smartphone and tablet (BYOD devices) without used MDM solution?

Let me describe our problem in more detailled:

Actually, we used a SSID for BYOD that include smartphones, Tablest, and legacy devices like barecode scanners (only work in 2.4ghz). But we use "skype for business" on smartphones and tablets for communication. Actually, we see that we have some communication problems (call drop) with skype when client move in the building. So I was wondering if the issue doesn't came during the roaming process with "band select" enabled on the wireless? So this is why I'm looking for a solution to disabled "band select" feature and also have the benefit of the 5Ghz band (less noise than 2.4Ghz and much bandwidth).

What do you think about this case? Do you think we have to change our wireless design to solved this problem?

Thanks,

Greg.

[pieterh]

You are talking about a complex environment, where wifi, qos and other network parameters need to be tuned to each other

so there is no easy answer.

please read these documents for reference and to check if and where your design differs

Enterprise Mobility 8.5 Design Guide

Microsoft Lync Client/Server in a Cisco Wireless LAN

[Leo Laohoo]

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@g.ska wrote:

Actually, we see that we have some communication problems (call drop) with skype when client move in the building. 

---

Like I said, the wireless clients make that final & ultimate decision which AP to join and which radio(s) to use.  

What kind of wireless clients see this "call drop"?  Android?  Apple?  Windows?

[pieterh]

>>> It's an option but we want to avoid to create more SSID in our infrastructure to save "airtime" <<<

if you got one ssid's using 5GHz only and a different using 2.4GHz only , there is no increase in "airtime"???

NB! the airtime problem is mainly in 2.4GHz band using 802.11b speeds

so there should be little impact when creating an extra ssid that uses 5GHz only.