--- a/examples/mesh.cc	Thu Apr 02 14:33:38 2009 +0400
+++ b/examples/mesh.cc	Thu Apr 02 17:26:20 2009 +0400
@@ -44,6 +44,7 @@
   double   step        = 100.0; // Grid with one-hop edge
   double   randomStart = 0.1;   // One beacon interval
   uint32_t nIfaces     = 1;
+  bool     chan        = false;
   bool     pcap        = false;
   
   // Command line arguments
@@ -53,6 +54,7 @@
   cmd.AddValue ("step",   "Size of edge in our grid, meters. [100 m]", step);
   cmd.AddValue ("start",  "Maximum random start delay, seconds. [0.1 s]", randomStart);
   cmd.AddValue ("interfaces", "Number of radio interfaces used by each mesh point. [1]", nIfaces);
+  cmd.AddValue ("channels",   "Use different frequency channels for different interfaces. [0]", chan);
   cmd.AddValue ("pcap",   "Enable PCAP traces on interfaces. [0]", pcap);
   
   cmd.Parse (argc, argv);
@@ -69,6 +71,7 @@
   
   // Install mesh point devices & protocols
   MeshWifiHelper mesh;
+  mesh.SetSpreadInterfaceChannels (chan);
   NetDeviceContainer meshDevices = mesh.Install (wifiPhy, nodes, nIfaces);
   
   // Setup mobility

--- a/src/devices/mesh/dot11s/dot11s-helper.cc	Thu Apr 02 14:33:38 2009 +0400
+++ b/src/devices/mesh/dot11s/dot11s-helper.cc	Thu Apr 02 17:26:20 2009 +0400
@@ -33,7 +33,10 @@
 namespace ns3 {
 namespace dot11s {
 
-MeshWifiHelper::MeshWifiHelper () : m_ssid("mesh"), m_randomStartDelay (Seconds (0))
+MeshWifiHelper::MeshWifiHelper () : 
+    m_ssid("mesh"), 
+    m_randomStartDelay (Seconds (0)),
+    m_spreadInterfaceChannels (false)
 {
 }
   
@@ -54,6 +57,13 @@
   m_randomStartDelay = t;
 }
 
+void 
+MeshWifiHelper::SetSpreadInterfaceChannels (bool s)
+{
+  m_spreadInterfaceChannels = s;
+}
+
+
 Ptr<WifiNetDevice> 
 MeshWifiHelper::CreateInterface (const WifiPhyHelper &phyHelper, Ptr<Node> node) const
 {
@@ -70,7 +80,10 @@
   device->SetMac (mac);
   device->SetPhy (phy);
   device->SetRemoteStationManager (manager);
-  
+  /*
+  if (channel > 0)
+    mac->SwitchFrequencyChannel (channel);
+  */
   return device;
 }
   
@@ -96,6 +109,23 @@
         mp->AddInterface (iface);
       }
     
+    // Set different channels on different ifaces
+    if (m_spreadInterfaceChannels)
+      {
+        std::vector<Ptr<NetDevice> > ifaces = mp->GetInterfaces ();
+        for (size_t i = 0; i < ifaces.size(); ++i)
+          {
+            uint32_t channel = i * 5;
+            
+            Ptr<WifiNetDevice> iface = ifaces[i]->GetObject<WifiNetDevice> ();
+            NS_ASSERT (iface);
+            Ptr<MeshWifiInterfaceMac> mac = iface->GetMac ()->GetObject<MeshWifiInterfaceMac> ();
+            NS_ASSERT (mac);
+            
+            mac->SwitchFrequencyChannel (channel);
+          }
+      }
+    
     // Install 802.11s protocols
     Ptr<PeerManagementProtocol> pmp = CreateObject<PeerManagementProtocol> ();
     bool pmp_ok = pmp->Install (mp);

--- a/src/devices/mesh/dot11s/dot11s-helper.h	Thu Apr 02 14:33:38 2009 +0400
+++ b/src/devices/mesh/dot11s/dot11s-helper.h	Thu Apr 02 17:26:20 2009 +0400
@@ -50,6 +50,14 @@
   /// Set maximum random start delay
   void SetRandomStartDelay (Time delay);
   /** 
+   *  \brief Spread/not spread frequency channels of MP interfaces. 
+   * 
+   *  If set to true different non-overlaping 20MHz frequency 
+   *  channels will be assigned to different mesh point interfaces.
+   */ 
+  void SetSpreadInterfaceChannels (bool); 
+  
+  /** 
    * \brief Install 802.11s mesh device & protocols on given node
    * 
    * \param phy                 Wifi PHY helper
@@ -73,6 +81,7 @@
 private:
   Ssid m_ssid;
   Time m_randomStartDelay;
+  bool m_spreadInterfaceChannels;
   
   /// Create single mesh interface NIC
   Ptr<WifiNetDevice> CreateInterface (const WifiPhyHelper &phyHelper, Ptr<Node> node) const;