Bug 2733

Summary:	Ideal wifi manager cannot handle NSS higher than 1
Product:	ns-3	Reporter:	sebastien.deronne
Component:	wifi	Assignee:	sebastien.deronne
Status:	RESOLVED FIXED
Severity:	normal	CC:	ns-bugs, tomh
Priority:	P3
Version:	ns-3.26
Hardware:	All
OS:	All
See Also:	https://www.nsnam.org/bugzilla/show_bug.cgi?id=2385
Attachments:	patch to fix

Description sebastien.deronne 2017-05-01 15:34:53 UTC

If Nss higher than 1 is configured in wifi-manager-example when using IdealWifiManager, only rates for Nss = 1 are selected.

This is because the same SNR threshold are obtained regardless the value of NSS, so once the highest SISO MCS is reached, the following condition is never entered anymore when NSS becomes higher than 1:
if (threshold > maxThreshold && threshold < station->m_lastSnrObserved)

Comment 1 sebastien.deronne 2017-05-15 12:48:20 UTC

Tom or Matias, can this be assigned to one of you?

Comment 2 Tom Henderson 2017-05-28 10:37:51 UTC

(In reply to sebastien.deronne from comment #1)
> Tom or Matias, can this be assigned to one of you?

I can take; may be related to 2385.

Comment 3 sebastien.deronne 2017-06-05 15:54:45 UTC

Tom, should this be moved to duplicate then?

Comment 4 Tom Henderson 2017-06-26 17:33:52 UTC

Created attachment 2878 [details]
patch to fix

I believe this patch fixes the issue (I tested many nss combinations by hand).  The overall code for ideal-wifi-manager.cc could be refactored a bit to reduce code duplication, but I did not take that step in this patch.

Comment 5 sebastien.deronne 2017-06-27 15:46:30 UTC

Thanks Tom, I will give a try.
We can still do some cleanup actions later on.
I also suggest to extend tests for nss>1 in our regression.

Comment 6 sebastien.deronne 2017-06-27 16:22:52 UTC

I did not try all combinations, but it seems the patch solves the reported issue, thanks Tom.
I will extend some more tests in the regression once the patch is pushed.

Comment 7 sebastien.deronne 2017-07-04 15:39:04 UTC

pushed in changeset 12952:8dbfaa3bc882