Bug 2607 – Minstrel HT manager results in an endless loop when a 802.11ac station is transmitting to a 802.11a access point

Bug 2607 - Minstrel HT manager results in an endless loop when a 802.11ac station is transmitting to a 802.11a access point


Summary:	Minstrel HT manager results in an endless loop when a 802.11ac station is tra...

Status:	RESOLVED FIXED

Product:	ns-3
Classification:	Unclassified
Component:	wifi
Version:	ns-3.26
Hardware:	All All

Importance:	P3 normal
Assigned To:	Matías Richart

URL:
Keywords:

Depends on:	2605
Blocks:
	Show dependency tree / graph

Reported:	2017-01-02 17:45 UTC by sebastien.deronne
Modified:	2017-01-11 14:40 UTC (History)
CC List:	3 users (show)

See Also:

Attachments
Correct overflow in channel width loop (615 bytes, patch) 2017-01-11 13:06 UTC, Matías Richart	Details \| Diff
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Description sebastien.deronne 2017-01-02 17:45:27 UTC

After applying the fix for bug 2605, I noticed minstrel HT manager results in an endless loop when a 802.11ac station is transmitting to a 802.11a access point.
From traces, it seems constantly initializing group 16.
This can be reproduced by using test script and fix attached for bug 2605 and
set AP standard to 802.11ac.

Comment 1 sebastien.deronne 2017-01-02 17:45:52 UTC

Is it also something Tom or Matias could investigate?

Comment 2 Matías Richart 2017-01-11 13:05:36 UTC

(In reply to sebastien.deronne from comment #1)
> Is it also something Tom or Matias could investigate?

The loop problem is because of an overflow. It seems I never test VHT correctly.
I get a throughput of 28.1682 Mbit/s, is that correct?

The test: ./waf --run 'test-backward-compatibility --apVersion=80211a --staVersion=80211ac --apRaa=Minstrel --staRaa=MinstrelHt'

Comment 3 Matías Richart 2017-01-11 13:06:19 UTC

Created attachment 2743 [details]
Correct overflow in channel width loop

Comment 4 sebastien.deronne 2017-01-11 13:07:07 UTC

(In reply to Matías Richart from comment #2)
> (In reply to sebastien.deronne from comment #1)
> > Is it also something Tom or Matias could investigate?
> 
> The loop problem is because of an overflow. It seems I never test VHT
> correctly.
> I get a throughput of 28.1682 Mbit/s, is that correct?
> 
> The test: ./waf --run 'test-backward-compatibility --apVersion=80211a
> --staVersion=80211ac --apRaa=Minstrel --staRaa=MinstrelHt'

Yes it makes sense

Comment 5 sebastien.deronne 2017-01-11 13:08:46 UTC

(In reply to Matías Richart from comment #3)
> Created attachment 2743 [details]
> Correct overflow in channel width loop

Thanks. I will give a try and I'll deliver the patch together with the fix for bug 2605.

Comment 6 sebastien.deronne 2017-01-11 14:40:14 UTC

Fixed in changeset 12526:47ec67af9904