wifi: (fixes #2826) Use lowest basic rate for management frames

RELEASE_NOTES

@@ -53,8 +53,9 @@ Bugs fixed
 - Bug 2813 - wifi: OFDM 10 MHz and 5 MHz PHYs do not have correct subcarrier frequency spacings
 - Bug 2820 - wifi: segmentation fault when Rrpaa wifi manager is used
 - Bug 2824 - ICMP opcode fr fragment timeout drop is wrong
-- Bug 2828 - OLSR simple P2P example produces wrong results
+- Bug 2826 - wifi: Management frames should be sent using the lowest basic rate
 - Bug 2827 - wifi: Active scanning not working with 802.11n/ac/ax
+- Bug 2828 - OLSR simple P2P example produces wrong results
 - Bug 2831 - wifi: runtime channel width switch has no effect
 - Bug 2836 - wifi: Missing VHT information in radiotap header when A-MPDU is used
 - Bug 2838 - wifi: ht-wifi-network crashes with RTS/CTS enabled and frequency set to 2.4GHz

examples/wireless/examples-to-run.py

@@ -45,7 +45,7 @@ cpp_examples = [
     ("he-wifi-network --simulationTime=0.25 --frequency=5 --useRts=0  --minExpectedThroughput=6 --maxExpectedThroughput=754", "True", "True"),
     ("he-wifi-network --simulationTime=0.3 --frequency=5 --useRts=1 --minExpectedThroughput=6 --maxExpectedThroughput=639", "True", "True"),
     ("he-wifi-network --simulationTime=0.25 --frequency=2.4 --useRts=0 --minExpectedThroughput=6 --maxExpectedThroughput=238", "True", "True"),
-    ("he-wifi-network --simulationTime=0.25 --frequency=2.4 --useRts=1 --minExpectedThroughput=6 --maxExpectedThroughput=224", "True", "True"),
+    ("he-wifi-network --simulationTime=0.3 --frequency=2.4 --useRts=1 --minExpectedThroughput=6 --maxExpectedThroughput=224", "True", "True"),
     ("simple-ht-hidden-stations --simulationTime=1 --minExpectedThroughput=22 --maxExpectedThroughput=22.5", "True", "True"),
     ("mixed-network --simulationTime=1", "True", "True"),
     ("wifi-aggregation --simulationTime=1 --verifyResults=1", "True", "True"),

src/wifi/doc/source/wifi-design.rst

@@ -176,15 +176,17 @@ The following details pertain to the physical layer and channel models:
 * PLCP preamble reception is not modeled
 * PHY_RXSTART is not supported
 * The current implementation assumes that secondary channels are always higher than primary channels
+* Cases where RTS/CTS and ACK are transmitted using HT/VHT/HE formats are not supported
 
 At the MAC layer, most of the main functions found in deployed Wi-Fi
 equipment for 802.11a/b/e/g/n/ac/ax are implemented, but there are scattered instances
-where some limitations in the models exist.Support for 802.11n and ac is evolving.
-Some additional details are as follows:
+where some limitations in the models exist. Support for 802.11n and ac is evolving.
+
+Some implementation choices that are not imposed by the standard are listed below:
 
 * BSSBasicRateSet for 802.11b has been assumed to be 1-2 Mbit/s
 * BSSBasicRateSet for 802.11a/g has been assumed to be 6-12-24 Mbit/s
-* cases where RTS/CTS and ACK are transmitted using HT/VHT/HE formats are not supported
+* The wifi manager always selects the lowest basic rate for management frames.
 
 Design Details
 **************

src/wifi/model/wifi-remote-station-manager.cc

@@ -859,7 +859,25 @@ WifiRemoteStationManager::GetDataTxVector (Mac48Address address, const WifiMacHe
       (void) found;
       return datatag.GetDataTxVector ();
     }
-  return DoGetDataTxVector (Lookup (address, header));
+  WifiTxVector txVector = DoGetDataTxVector (Lookup (address, header));
+  if (header->IsMgt ())
+    {
+      //Use the lowest basic rate for management frames
+      WifiMode mgtMode;
+      if (GetNBasicModes () > 0)
+        {
+          mgtMode = GetBasicMode (0);
+        }
+      else
+        {
+          mgtMode = GetDefaultMode ();
+        }
+      txVector.SetMode (mgtMode);
+      txVector.SetPreambleType (GetPreambleForTransmission (mgtMode, address));
+      txVector.SetChannelWidth (GetChannelWidthForTransmission (mgtMode, m_wifiPhy->GetChannelWidth ()));
+      txVector.SetGuardInterval (ConvertGuardIntervalToNanoSeconds (mgtMode, m_wifiPhy->GetShortGuardInterval (), m_wifiPhy->GetGuardInterval ()));
+    }
+  return txVector;
 }
 
 WifiTxVector