AP ONE "handoff" to another AP ONE in local network not working well


#1

**I am trying to understand how multiple AP ONE units with the same SSID behave behind a Balance router. I have a Balance 310 with firmware 5.4.9 connected to three AP ONE units. These units collectively provide excellent signal coverage over an area of about 25,000 square feet which includes inside and outside of two buildings. My goal is to provide seamless coverage to wireless clients over this area, both inside and outside of the buildings. Nominally, the signal strengths are “great” except the individual AP ONE units “hang on” to a connected client too long when they should “hand off” to an adjacent AP ONE. I have tested how they hand-off clients when the client is moving from the area served by one AP ONE to the area served by another. All of the AP ONE units have the SSID = RADIO.

For testing, I have set up with just TWO AP ONEs for the moment. One AP one is on WiFi channel 1 and the other is on Channel 8.

What I find is that if I walk between the two coverage areas, the signal on the distant AP ONE goes down to one “bump” on my iPad and meanwhile the signal from the other AP ONE will be coming up to the full four “bumps” in actual strength. But he weak AP ONE “hangs on” to the client iPad until the signal disappears on the iPad. then it will move to the stronger RADIO AP ONE with the full strength signal. This is unsatisfactory as an iPad or other device with this minimum signal cannot actually communicate on the WiFi link. I find this same performance with a Dell laptop with an Intel WiFi Client.

I was thinking that the Balance 310 would be able to monitor the growing weaker signal from the ipad on the first AP ONE and then switch automatically to the signal from the second AP ONE without the iPad having to go thru a total signal dropout to make the change. But this is not happening.

My questions are:

  1. Is the above how things are supposed to work?
  2. Do I need the later version 6 firmware for the Balance 310 to get the functionality I am looking for?
  3. If so is there a charge? Version 6 Balance firmware appears to need a “key”.

Thanks!

Joe
**


#2

Hi Joe,

1), 2) & 3) Roaming is a mobile station decision. The mobile station is responsible for deciding when it needs to roam, detect, evaluate, and roam to another AP. WLAN standards bodies (IEEE) and industry bodies (Wi-Fi Alliance) do not specify when a mobile station should roam, or how the mobile station determines to which AP it should roam, which lead to individual wireless adapter vendor create their own standard on the roaming mechanism. Thus, your outcome is normal.


#3

Thanks! I was afraid of that. This means that the PepWave/Peplink configuration described above cannot actually have truly “seamless roaming” on a multi-AP network.

I assume this means more explicitly that Peplink/Pepwave does not have the same kind of “Wireless Lan Controller” function as available in Cisco Aironet equipment? I quote below from a description on how the Aironet (enterprise) equipment functions.

“The Aironet (enterprise) devices have the ability to utilize a wireless LAN controller which can help keep devices connected to the stronger signal and allow truly seamless roaming between APs.”

I believe (but am not positive that) these work by the Lan Controller continually getting client signal strength feedback from the various APs on a network and when the signal from a particular client gets low on one AP, the Lan Controller drops that client (momentarily?) so the client can try to find a stronger AP. This is not a perfect solution, but it seems to work pretty well in practice.

I very much appreciate your answer as I was under the wrong impression about how the Balance Routers with attached AP ONEs worked. Hopefully Peplink/Pepwave will work toward having a “truly seamless roaming” capability as this is highly desirable feature in multi-AP applications.


#4

Hi Joe,

Thank you for your comments. We will explore the possibilities on implementing any roaming mechanism with WLC.


#5

Hi TK,

was roaming mechanism implemented since that post? How can we adjust signal strength level that makes AP drop the client when there is stronger signal available?

BR
Jakub


#6

@JakubN, please find the screenshot below. You can adjust the accepted client signal strength threshold. The connection from the client will be denied if the signal strength is below the defined value.


#7

hi @TK, so do i need to put 20 if I want the thresh hold to be -75dBm? as shown below?
This is taken from my AP ONE ENT in our office with firmware 3.5.4


#8

@rocknolds, yes you are right


#9

How does 20 convert to -75dBm?


#10

The default Client Signal Strength Threshold is -95dBm. This will be the calculation if you enter 20.

-95 + 20 = -75dBm


#11

thanks TK :slight_smile: