Fist off - Asus terminology of the wifi signal strength seems to be mixing RSSI with dBm.
To my humble understanding "dBm and RSSI are different units of measurement that both represent the same thing: signal strength. The difference is that RSSI is a relative index, while dBm is an absolute number representing power levels in mW (milliwatts).
RSSI is a term used to measure the relative quality of a received signal to a client device, but has no absolute value. The IEEE 802.11 standard specifies that RSSI can be on a scale of 0 to up to 255 and that each chipset manufacturer can define their own “RSSI_Max” value. It’s all up to the manufacturer (which is why RSSI is a relative index), but you can infer that the higher the RSSI value is, the better the signal is.
Since RSSI varies greatly between chipset manufacturers a more standardized, absolute measure of signal strength is: received signal power - measured in decibels, or dBm on a logarithmic scale. Basically, the closer to 0 dBm, the better the signal is."
That aside and to help leverage signal strength measurement most effectively for channel planning decisions it is recommended to utilize available tools, e.g. a smart phone app like Network Analyzer for Android.
If one cares the difference in signal strength in between 20/80 MHz channel width in the 5 GHz spectrum should be noted, i.e. 80 MHz has a lesser signal strength than the 20 MHz channel width.
It needs to be decided what is the baseline trigger should be:
- Bandwidth Utilization a/o
- signal strength (RSSI/dBm) a/o
- PHY(1) Rate (Less/Greater) a/o
- VHT(2) (802.11ac and non-ac STA(3))
(1) Physical Layer
(2) Very High Throughput (802.11ac and 802.11ad significantly increase the maximum data rates beyond that offered by 802.11n)
(3) Station (is a device that has the capability to use the 802.11 protocol)
After checking the signal strength in the various spots I decided for a simple baseline trigger:
Steering Trigger Condition -> Band 2.4 GHz -> Signal Strength Less -65 dBm
(-65 dBm on the 2.4 GHz band is arbitrary to this particular location in comparison to the available signal strength of the 5 GHz band with the 20/80 MHz channel widths)
Nothing else on there and nothing on the 5 GHz band. This would kick clients off the 2.4 GHz band and on to the "Target Band" (5 GHz) specified in "Interface Select and Qualify Procedures" for any signal strength (on the 2.4 GHz band) between 0 dBM and -65 dBm. For any signal strength between -66 dBm and -100 dBm on the 2.4 GHz band the client would remain on the 2.4 GHz band therefore.
Next refining the 5 GHZ band:
- STA Selection Policy -> Band 5 GHz1 -> PHY Rate Less < 200 Mbps
- STA Selection Policy -> Band 5 GHz2 -> PHY Rate Less < 100 Mbps
If the PHY drops below the target policy it will be kicked off the respective 5 GHz band and on to the "Target Band" specified in "Interface Select and Qualify Procedures"
Additional refining the 5 GHz band:
- Interface Select and Qualify Procedures -> Band 5 GHz1 -> Bandwidth Utilization 60%
- Interface Select and Qualify Procedures -> Band 5 GHz2 -> Bandwidth Utilization 70%
If the bandwidth saturation exceeds the target policy it will be kicked off the respective 5 GHz band and on to the "Target Band" specified in "Interface Select and Qualify Procedures"
That is how it looks in the GUI