how modify byte buffer in packet ns3

[Belkneni Maroua]

hello, I want to invert the bits of a package sent in one wireless networks,Here is my code, please help me  :

#include "ns3/core-module.h"

#include "ns3/wifi-module.h"

#include "ns3/mobility-module.h"

#include "ns3/applications-module.h"

#include "ns3/internet-module.h"

#include "ns3/network-module.h"

#include "ns3/config-store-module.h"

using namespace ns3;

NS_LOG_COMPONENT_DEFINE ("wifiScriptExample");

int main (int argc, char *argv[])

{ 

LogComponentEnable ("UdpEchoClientApplication", LOG_LEVEL_INFO);

LogComponentEnable ("UdpEchoServerApplication", LOG_LEVEL_INFO);

NodeContainer wifiNodes;

wifiNodes.Create (3);

YansWifiPhyHelper wifiPhy = YansWifiPhyHelper::Default ();

YansWifiChannelHelper wifiChannel = YansWifiChannelHelper::Default ();

wifiPhy.SetChannel (wifiChannel.Create ());

WifiHelper wifi = WifiHelper::Default ();

NqosWifiMacHelper wifiMac = NqosWifiMacHelper::Default ();

wifi.SetRemoteStationManager ("ns3::ConstantRateWifiManager");

wifiMac.SetType("ns3::AdhocWifiMac");

NetDeviceContainer wifiDevices = wifi.Install( wifiPhy, wifiMac, wifiNodes );

MobilityHelper mobility;

mobility.SetPositionAllocator ("ns3::GridPositionAllocator", 

"MinX", DoubleValue (0.0),

"MinY", DoubleValue (0.0),

"DeltaX", DoubleValue (5.0),

"DeltaY", DoubleValue (10.0),

"GridWidth", UintegerValue (3),

"LayoutType", StringValue ("RowFirst"));

mobility.SetMobilityModel ("ns3::ConstantPositionMobilityModel");

mobility.Install (wifiNodes);

InternetStackHelper internet;

internet.Install (wifiNodes);

Ipv4AddressHelper address;

address.SetBase ("10.1.1.0", "255.255.255.0");

Ipv4InterfaceContainer wifiInterfaces;

wifiInterfaces = address.Assign( wifiDevices );

UdpEchoServerHelper echoServer (9);

ApplicationContainer serverApps = echoServer.Install (wifiNodes.Get( 0 ));

serverApps.Start (Seconds (1.0));

serverApps.Stop (Seconds (10.0));

UdpEchoClientHelper echoClient (wifiInterfaces.GetAddress (0), 9);

echoClient.SetAttribute ("MaxPackets", UintegerValue (2));

echoClient.SetAttribute ("Interval", TimeValue (Seconds (1.)));

echoClient.SetAttribute ("PacketSize", UintegerValue (1024));

ApplicationContainer clientApps = echoClient.Install ( wifiNodes.Get( 2 ) );

clientApps.Start( Seconds (2.0) );

clientApps.Stop( Seconds (10.0) );

Ipv4GlobalRoutingHelper::PopulateRoutingTables ();

Simulator::Stop (Seconds (5.05));

Simulator::Run ();

Simulator::Destroy ();

return 0;

}

[Konstantinos]

Hi,

You have made a similar question couple of days ago and you got an answer, that you have to use/modify the channel.

https://groups.google.com/d/msg/ns-3-users/nUcX48VzOC4/AWhPV_1qzq0J

Here you are using the default YansWifiChannel:

YansWifiChannelHelper wifiChannel = YansWifiChannelHelper::Default ();

So, I would suggest that you follow the help you are given and if you have a specific question on that, we could help.

You will not modify the packet byte buffer in your scenario script (that is what you posted) but in the channel implementation.

[Belkneni Maroua]

ok, Thank you for your answer

[Belkneni Maroua]

hi,I want to eliminate YansWifiChannel by default and to make a cannel by using "simple - channel.cc"  I have not find how to implement it in my code and how to associate the new canal with "wifiphy". here is my code

using namespace ns3;

NS_LOG_COMPONENT_DEFINE ("jdidScriptExample");

int main (int argc, char *argv[])

{ 

LogComponentEnable ("UdpEchoClientApplication", LOG_LEVEL_INFO);

LogComponentEnable ("UdpEchoServerApplication", LOG_LEVEL_INFO);

NodeContainer wifiNodes;

wifiNodes.Create (3);

YansWifiPhyHelper wifiPhy = YansWifiPhyHelper::Default ();

class SimpleChannel : public Channel

{

public:

  static TypeId GetTypeId (void);

  SimpleChannel ();

  void Send (Ptr<Packet> p, uint16_t protocol, Mac48Address to, Mac48Address from,

         Ptr<SimpleNetDevice> sender);

  void Add (Ptr<SimpleNetDevice> device);

  // inherited from ns3::Channel

  virtual uint32_t GetNDevices (void) const;

  virtual Ptr<NetDevice> GetDevice (uint32_t i) const;

private:

  std::vector<Ptr<SimpleNetDevice> > m_devices;

};

/*wifiPhy.SetChannel (SimpleChannel);*/