On February 5, 2019 at 11:50, dsp81 said...
Design is critical to avoid sticky clients. There are protocols for roaming, but in the end the client normally controls how it will roam. Some vendors allow you to disassociate a client below a certain RSSI threshold, but I haven’t had much success with that strategy.
I disable lower data rates and adjust power levels to maintain correct overlap between APs cells (approximately 20% overlap between cells at your lowest data rate). The lower data rates have longer effective transmission distances and can result in sticky clients. In residential I normally make 24 Mbps mandatory and disable everything below. I leave all higher data rates as supported. Then I start tuning power levels and can re-enable data rates, if necessary (I would re-enable a data rate if the coverage is poor at full power). I move in reverse, trying to maintain the highest data rate possible. If you don’t have good coverage unless using 1.5 Mbps and full power, you need to re-evaluate your design.
Also make sure you do not have overlapping adjacent channels. This more difficult on 2.4 than 5 as there are only 3 non-overlapping channels (1, 6, and 11). 5 GHz does not carry as well as 2.4 GHz through walls and will likely have different power requirements. There are products that will measure the RF environment and dynamically set channel and power levels (Cisco CleanAir, for example).
This link is for 2.4 GHz channel planning, but the principles are applicable to 5 GHz, as well.
[Link: blog.aerohive.com]This is exactly correct - the decision is made by the client device and it depends on far more than simply RSSI or SNR. Disabling low data rates is a good step in the right direction and may solve your problem. I settle in on 12 go 18 most of the time, but it really depends. Force clients to 5 if you can, turn down radio power, shut off 1/2 of the 2.4 radios, etc, be very careful with your channel reuse plan, use small cell sizes, etc... Some of that is more SMB than residential. Vendors have sone control and secret sauce, but are prisoners to the same standard. I recommend starting with the fundamental stuff first. Rarely do I have more than 3 APs broadcasting 2.4 in a residential home... depending on size and construction materials of course.
I am not sure what your use case is, but for anything except VoWiFi, what apps are you having issues with? And if you are trying to do 802.11r voice then.... you need secondary coverage based on the headset requirements. it is really hit or miss if most phones even support it. It gets deep fast unless you have the infrastructure and design tools for it. On that note - I would stay away form SCA....
dsp81 gives good advice. In short, disable a few of the lower data rates if you can. Turn the 2.4 power down. Encourage 5Ghz. Use only 1,6, and 11 in 2.4 - with 20MHz wide channels.
Hope this helps.
