Question

why sta alway attach to the long distant ap, but not to the nearby one?

  • 23 March 2021
  • 5 replies
  • 44 views

Userlevel 1

hi there,
I deploy two aerohive ap230 at home, one is on study room, the other is on living room.


when I sit on the study room and handheld two android phone, they always connect to the living room's ap and got a very low phy datarate. why not attach to the nearby ap on study room?

I have been tried to kick a sta with: clear auth station mac <client MAC>, but very soon, it reconnect to the living room ap again. not even try to have a look at the nearby one.


how to troubleshoot this situation?


5 replies

Userlevel 6

I would recommend lowering the power on the AP in the living room so the signal isn’t being heard in the study room. Ultimately, the client device will choose which AP to connect to based on where it hears the strongest signal coming from. You can lower the power by logging in to your XIQ instance> Go to Manage> Devices> Click on the hostname of the living room AP> Go to Configure (left hand side menu)> Go to Interface Settings under the Configuration header (still on that left hand side menu, below Configure)> Expand Wireless Interfaces> Scroll down to Transmission Power> Switch it to Manual> Set the power level you want (20 is the highest power level with the longest signal reach, 1 is the lowest power level with the shortest signal reach). For a home environment, I’d suggest starting with a max power level of 10 and monitoring things from there.  

Userlevel 1

isn't aerohive support dynamic rf management, including the transmit power adjustment automaticly? afterall, the interference exist all the time

Userlevel 1

I am trying to figure acsp out. here is ‘show acsp’ result:

the ap model is ap122x, version 10.0r8

does it mean the acsp is enabled on both interface?

but I have been select the use-last-selection option, why the cli result doesn’t reflect it?

and the tx power is correct cos I set it according to sam’s suggestion.

Userlevel 6
Badge

Hi,

 

What were the ACSP constraints configured? I mean the power floor and max drop. Depending on the environment, APs can do various stuff but the algorithm logic might be different than human logic.

Good to know, an AP with just 1 dBm of power delivered to the antenna (IR) and 3 dBi gain antenna (= 4 dBm radiated power - EIRP) can deliver WiFi-detectable signal for about 0.5 km in an open area, and voice-valid signal for tens of meters. That’s why we should love walls and low power. 😉 Low power would also be good in case of enterprise mobile environment density. On the other hand, we may be at risk of TxP mismatch when AP power is significantly lower/higher than the STA. Then we may experience increase in frame retries.

What do you see under these commands?

show acsp neighbor

show acsp channel-info

show acsp channel-info detail

show interface wifi0 counter

Might be useful to look around and try to spot potential reasons for power being the highest allowed for the radio. And to look for other kinds of issues in the future.

 

Hope that helps,

Tomasz

 

P.S. More on ACSP basics: https://docs.aerohive.com/330000/docs/guides/AerohiveChannelSelectionProtocol.pdf

Regarding Androids connecting to the living room AP, what if you tried to forget the SSID (wipe its settings) on the phone and try to reconnect while sitting in the study room? If it wasn't about power levels, I’d try to see are there any WLAN/security-related BSSID preferences in Android internals.

Userlevel 1

Hi,

 

What were the ACSP constraints configured? I mean the power floor and max drop. Depending on the environment, APs can do various stuff but the algorithm logic might be different than human logic.

Good to know, an AP with just 1 dBm of power delivered to the antenna (IR) and 3 dBi gain antenna (= 4 dBm radiated power - EIRP) can deliver WiFi-detectable signal for about 0.5 km in an open area, and voice-valid signal for tens of meters. That’s why we should love walls and low power. 😉 Low power would also be good in case of enterprise mobile environment density. On the other hand, we may be at risk of TxP mismatch when AP power is significantly lower/higher than the STA. Then we may experience increase in frame retries.

What do you see under these commands?

show acsp neighbor

show acsp channel-info

show acsp channel-info detail

show interface wifi0 counter

Might be useful to look around and try to spot potential reasons for power being the highest allowed for the radio. And to look for other kinds of issues in the future.

 

Hope that helps,

Tomasz

 

P.S. More on ACSP basics: https://docs.aerohive.com/330000/docs/guides/AerohiveChannelSelectionProtocol.pdf

Regarding Androids connecting to the living room AP, what if you tried to forget the SSID (wipe its settings) on the phone and try to reconnect while sitting in the study room? If it wasn't about power levels, I’d try to see are there any WLAN/security-related BSSID preferences in Android internals.

thanks @Tomasz for so detailled explanation, my home environment is too small for poc. so I am going to deploy six pics ap230s on a school office to learn how aerohive works, will post more information late, stay tune...

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