Bug 2827

Summary: Active scanning not working with 802.11n/ac/ax
Product: ns-3 Reporter: sebastien.deronne
Component: wifiAssignee: sebastien.deronne
Status: RESOLVED FIXED    
Severity: major CC: bbojovic, ns-bugs
Priority: P3    
Version: ns-3.27   
Hardware: All   
OS: All   
Attachments: patch to fix

Description sebastien.deronne 2017-11-21 03:18:13 UTC
I wrote a very simple script using 802.11ac with active probing enabled (no traffic, just a station trying to get associated to an AP). I see a flow of probe requests followed by probe responses, but no association request being triggered.

I added some more traces, and I noticed this return (in StaWifiMac:Receive) was hit because rates are not matching:

          for (uint32_t i = 0; i < m_phy->GetNBssMembershipSelectors (); i++)
            {
              uint32_t selector = m_phy->GetBssMembershipSelector (i);
              if (!rates.IsSupportedRate (selector))
                {
                  return;
                }
            }

This is not seen with legacy standards (a/b/g), but this only occurs for n and ac (and I guess ax as well).

I will investigate this issue.
Comment 1 sebastien.deronne 2017-11-21 11:55:48 UTC
Created attachment 2963 [details]
patch to fix

Fix seems quite obvious in the end, this could never have been working.
Comment 2 sebastien.deronne 2017-11-25 10:27:00 UTC
pushed in changeset 13186:ee2d71085f6c