WifiNetDevices can return the number of transmission queues based on …

…the installed MAC

For WifiNetDevices, the number of transmission queues is set when installing the MAC (in
WifiNetDevice::SetMac), given that the number of queues is 4 if the MAC supports
QoS and 1 otherwise.

src/wifi/model/regular-wifi-mac.cc

@@ -439,6 +439,15 @@ RegularWifiMac::GetSsid (void) const
   return m_ssid;
 }
 
+uint8_t
+RegularWifiMac::GetTxQueuesN (void) const
+{
+  if (m_qosSupported)
+    return 4;
+
+  return 1;
+}
+
 void
 RegularWifiMac::SetBssid (Mac48Address bssid)
 {

src/wifi/model/regular-wifi-mac.h

@@ -136,6 +136,10 @@ class RegularWifiMac : public WifiMac
    * \return the ssid which this MAC layer is going to try to stay in.
    */
   virtual Ssid GetSsid (void) const;
+  /**
+   * \return the number of transmission queues handled by this MAC layer.
+   */
+  virtual uint8_t GetTxQueuesN (void) const;
   /**
    * \param address the current address of this MAC layer.
    */

src/wifi/model/wifi-mac.h

@@ -133,6 +133,10 @@ class WifiMac : public Object
    * \return the ssid which this MAC layer is going to try to stay in.
    */
   virtual Ssid GetSsid (void) const = 0;
+  /**
+   * \return the number of transmission queues handled by this MAC layer.
+   */
+  virtual uint8_t GetTxQueuesN (void) const = 0;
   /**
    * \param address the current address of this MAC layer.
    */

src/wifi/model/wifi-net-device.cc

@@ -131,6 +131,7 @@ void
 WifiNetDevice::SetMac (Ptr<WifiMac> mac)
 {
   m_mac = mac;
+  SetTxQueuesN (m_mac->GetTxQueuesN ());
   CompleteConfig ();
 }