Bug 2929 – Prevent IdealWifiManager from adding incompatible modes in IEEE 802.11ac

Bug 2929 - Prevent IdealWifiManager from adding incompatible modes in IEEE 802.11ac


Summary:	Prevent IdealWifiManager from adding incompatible modes in IEEE 802.11ac

Status:	RESOLVED FIXED

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

Importance:	P3 normal
Assigned To:	sebastien.deronne

URL:
Keywords:

Depends on:
Blocks:
	Show dependency tree / graph

Reported:	2018-06-16 02:11 EDT by Varun Reddy
Modified:	2020-04-18 09:37 EDT (History)
CC List:	2 users (show)

See Also:

Attachments
Patch (1.22 KB, patch) 2018-06-16 02:11 EDT, Varun Reddy	Details \| Diff
Test Case (7.85 KB, text/x-c++src) 2018-06-18 10:00 EDT, Varun Reddy	Details
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Description Varun Reddy 2018-06-16 02:11:16 EDT

Created attachment 3112 [details]
Patch

WifiMode throws an error message when a mode is used with incompatible channel widths or spatial streams. For instance, when channel 36 (20 MHz channel) is used with ideal wifi manager, the following message is thrown:

assert failed. cond="IsAllowed (channelWidth, nss)", msg="VHT MCS 9 forbidden at 20 MHz when NSS is 1", file=../src/wifi/model/wifi-mode.cc, line=214

However, the user has no control over which MCSs are added to Ideal Wifi Manager, despite knowing that MCS 9 is incompatible when Channel 36. This patch simply prevents IdealWifiManager from adding incompatible modes.

Comment 1 sebastien.deronne 2018-06-18 05:57:00 EDT

Varun, do you have any test case to reproduce the assert?

Comment 2 Varun Reddy 2018-06-18 10:00:21 EDT

Created attachment 3113 [details]
Test Case

The test case is a modified version of examples/wireless/wifi-tcp.cc
IdealWifiManager is used with channel number 36, which is a 20 MHz channel.

Comment 3 sebastien.deronne 2020-04-18 09:37:59 EDT

This bug can be closed, in the meantime there is a check in Ideal whether a mode is valid or not, and if not is getting skipped.