Re: Handover IEEE 802.11r FT BSS

[Ramon Fontes]

Hello, Please find answers below. 

> Is the use of bgscan mandatory? Is it standardized by IEEE? I want to emulate real-world handover without external tools. If I don't use bgscan, how will it affect the handover process?

AFAIK, all the Linux systems use bgscan and this includes mobile OSes (e.g. android).

> Does my configuration ensure the handover is processed using FT 802.11r? How can I verify this? The handover works as observed. Is my approach with the Mininet script and wpa_supplicant acceptable, even without specifying encryption for the client in the Mininet script?

You can use wireless tools such as wpa_cli.

> For mobility, I want to move the station from AP1 to AP2 to AP3 and then back from AP3 to AP2 to AP1. Is there a way to customize the mobility with a custom trajectory?

Yes. Please don't ask me how. :) There are sample files at /examples that may help you.

> Does net.addLink(ap2, ap1) add a wireless link or a wired link between the two access points?

Wired Link! Ref: https://mn-wifi.readthedocs.io/en/latest/usage.html#creating-wired-link-between-sta-and-ap

> Lastly, do you have any idea please  how to perform over-the-DS or over-the-air handover with 802.11r?

If you use bgscan and you have 802.11r you have everything you need to perform over-the-DS

[Ramon Fontes]

1. Bgscan does this automatically based on the signal strength. 

2. I strongly suggest you to read about wpa_supplicant.

On Thu, Jun 27, 2024, 23:17 Younes Korbi <korbi.yo...@gmail.com> wrote:

Thank you for your response 

1) can you please clarify ? Because before i asked you the question about mobility, I saw all the questions in the group and the /examples didn't answer my question. I want to perform "go and back" , ap1 to ap2 to ap3 then ap3 to ap2 to ap2

2) the default mode of handover with 11r is over the ds? That's what you mean 

[Ramon Fontes]

Really?

Did you take a look at https://github.com/intrig-unicamp/mininet-wifi/blob/master/examples/mobility.py??

[Ramon Fontes]

> In my experiments, it seems that the bgscan doesn't work properly because the reassociation to the new AP happens when the signal falls below -80dm and when the sta leave the the coverage area of the old AP

This depends on your setup. Also, this information doesn't help. Any useful information from wpa_cli??

> so regarding your opinion should I deactivate the networkmanager in linux?

NM must be deactivated!

> Last thing  Ramon please, can you explain the parameters mob_rep and reverse in the startmobility function ? because I adjusted them to see what happened but nothing. I'm looking to design my own trajectory or my own mobility pattern

Please try a "git pull" and then "sudo make install". mob_rep means mobility repetition.

[Ramon Fontes]

Dear Younes,

Honestly, you won't help me or yourself by sending multiple messages without you doing a detailed analysis of everything. There is a lot to be seen with wpa_cli beyond simply analyzing the status.

[Ramon Fontes]

You did not use any of the wpa_cli features for network scanning. :(  If you don't do a more detailed investigation, I wouldn't be able to help you, really.