using namespace ns3;

79

80 NS_LOG_COMPONENT_DEFINE ("WifiSimpleAdhocGrid");

81

82 void ReceivePacket (Ptr socket)

83 {

84 while (socket->Recv ())

85 {

86 NS_LOG_UNCOND ("Received one packet!");

87 }

88 }

89

90 static void GenerateTraffic (Ptr socket, uint32_t pktSize,

91 uint32_t pktCount, Time pktInterval )

92 {

93 if (pktCount > 0)

94 {

95 socket->Send (Create (pktSize));

96 Simulator::Schedule (pktInterval, &GenerateTraffic,

97 socket, pktSize,pktCount - 1, pktInterval);

98 }

99 else

100 {

101 socket->Close ();

102 }

103 }

104

105

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

107 {

108 std::string phyMode ("DsssRate1Mbps");

109 double distance = 500; // m

110 uint32_t packetSize = 1000; // bytes

111 uint32_t numPackets = 1;

112 uint32_t numNodes = 25; // by default, 5x5

113 uint32_t sinkNode = 0;

114 uint32_t sourceNode = 24;

115 double interval = 1.0; // seconds

116 bool verbose = false;

117 bool tracing = false;

118

119 CommandLine cmd;

120

121 cmd.AddValue ("phyMode", "Wifi Phy mode", phyMode);

122 cmd.AddValue ("distance", "distance (m)", distance);

123 cmd.AddValue ("packetSize", "size of application packet sent", packetSize);

124 cmd.AddValue ("numPackets", "number of packets generated", numPackets);

125 cmd.AddValue ("interval", "interval (seconds) between packets", interval);

126 cmd.AddValue ("verbose", "turn on all WifiNetDevice log components", verbose);

127 cmd.AddValue ("tracing", "turn on ascii and pcap tracing", tracing);

128 cmd.AddValue ("numNodes", "number of nodes", numNodes);

129 cmd.AddValue ("sinkNode", "Receiver node number", sinkNode);

130 cmd.AddValue ("sourceNode", "Sender node number", sourceNode);

131

132 cmd.Parse (argc, argv);

133 // Convert to time object

134 Time interPacketInterval = Seconds (interval);

135

136 // disable fragmentation for frames below 2200 bytes

137 Config::SetDefault ("ns3::WifiRemoteStationManager::FragmentationThreshold", StringValue ("2200"));

138 // turn off RTS/CTS for frames below 2200 bytes

139 Config::SetDefault ("ns3::WifiRemoteStationManager::RtsCtsThreshold", StringValue ("2200"));

140 // Fix non-unicast data rate to be the same as that of unicast

141 Config::SetDefault ("ns3::WifiRemoteStationManager::NonUnicastMode",

142 StringValue (phyMode));

143

144 NodeContainer c;

145 c.Create (numNodes);

146

147 // The below set of helpers will help us to put together the wifi NICs we want

148 WifiHelper wifi;

149 if (verbose)

150 {

151 wifi.EnableLogComponents (); // Turn on all Wifi logging

152 }

153

154 YansWifiPhyHelper wifiPhy = YansWifiPhyHelper::Default ();

155 // set it to zero; otherwise, gain will be added

156 wifiPhy.Set ("RxGain", DoubleValue (-10) );

157 // ns-3 supports RadioTap and Prism tracing extensions for 802.11b

158 wifiPhy.SetPcapDataLinkType (YansWifiPhyHelper::DLT_IEEE802_11_RADIO);

159

160 YansWifiChannelHelper wifiChannel;

161 wifiChannel.SetPropagationDelay ("ns3::ConstantSpeedPropagationDelayModel");

162 wifiChannel.AddPropagationLoss ("ns3::FriisPropagationLossModel");

163 wifiPhy.SetChannel (wifiChannel.Create ());

164

165 // Add an upper mac and disable rate control

166 WifiMacHelper wifiMac;

167 wifi.SetStandard (WIFI_PHY_STANDARD_80211b);

168 wifi.SetRemoteStationManager ("ns3::ConstantRateWifiManager",

169 "DataMode",StringValue (phyMode),

170 "ControlMode",StringValue (phyMode));

171 // Set it to adhoc mode

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

173 NetDeviceContainer devices = wifi.Install (wifiPhy, wifiMac, c);

174

175 MobilityHelper mobility;

176 mobility.SetPositionAllocator ("ns3::GridPositionAllocator",

177 "MinX", DoubleValue (0.0),

178 "MinY", DoubleValue (0.0),

179 "DeltaX", DoubleValue (distance),

180 "DeltaY", DoubleValue (distance),

181 "GridWidth", UintegerValue (5),

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

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

184 mobility.Install (c);

185

186 // Enable OLSR

187 OlsrHelper olsr;

188 Ipv4StaticRoutingHelper staticRouting;

189

190 Ipv4ListRoutingHelper list;

191 list.Add (staticRouting, 0);

192 list.Add (olsr, 10);

193

194 InternetStackHelper internet;

195 internet.SetRoutingHelper (list); // has effect on the next Install ()

196 internet.Install (c);

197

198 Ipv4AddressHelper ipv4;

199 NS_LOG_INFO ("Assign IP Addresses.");

200 ipv4.SetBase ("10.1.1.0", "255.255.255.0");

201 Ipv4InterfaceContainer i = ipv4.Assign (devices);

202

203 TypeId tid = TypeId::LookupByName ("ns3::UdpSocketFactory");

204 Ptr recvSink = Socket::CreateSocket (c.Get (sinkNode), tid);

205 InetSocketAddress local = InetSocketAddress (Ipv4Address::GetAny (), 80);

206 recvSink->Bind (local);

207 recvSink->SetRecvCallback (MakeCallback (&ReceivePacket));

208

209 Ptr source = Socket::CreateSocket (c.Get (sourceNode), tid);

210 InetSocketAddress remote = InetSocketAddress (i.GetAddress (sinkNode, 0), 80);

211 source->Connect (remote);

212

213 if (tracing == true)

214 {

215 AsciiTraceHelper ascii;

216 wifiPhy.EnableAsciiAll (ascii.CreateFileStream ("wifi-simple-adhoc-grid.tr"));

217 wifiPhy.EnablePcap ("wifi-simple-adhoc-grid", devices);

218 // Trace routing tables

219 Ptr routingStream = Create ("wifi-simple-adhoc-grid.routes", std::ios::out);

220 olsr.PrintRoutingTableAllEvery (Seconds (2), routingStream);

221 Ptr neighborStream = Create ("wifi-simple-adhoc-grid.neighbors", std::ios::out);

222 olsr.PrintNeighborCacheAllEvery (Seconds (2), neighborStream);

223

224 // To do-- enable an IP-level trace that shows forwarding events only

225 }

226

227 // Give OLSR time to converge-- 30 seconds perhaps

228 Simulator::Schedule (Seconds (30.0), &GenerateTraffic,

229 source, packetSize, numPackets, interPacketInterval);

230

231 // Output what we are doing

232 NS_LOG_UNCOND ("Testing from node " << sourceNode << " to " << sinkNode << " with grid distance " << distance);

233

234 Simulator::Stop (Seconds (33.0));

235 Simulator::Run ();

236 Simulator::Destroy ();

237

238 return 0;

239 }

Please do the following modifications to the example script wifi-simple-adhoc-grid.cc

Copy it from the example folder to the scratch folder and change its name to anything you like such as my-first.cc(otherwise, your change may not be reflected in the simulation).

Let the simulation stop at 60 seconds.

In function void HYPERLINK "https://www.nsnam.org/doxygen/wifi-simple-adhoc-grid_8cc.html" \l "a80dc0d980be124d8d5c4ee0b7943bfae" ReceivePacket ( HYPERLINK "https://www.nsnam.org/doxygen/classns3_1_1_ptr.html" Ptr socket), record current time in the log when a packet is received. The final log is like Received one packet at xxx, where xxx represents the time in the simulation that thepacket is received (Hint: you need to google how to get simulation time in ns3).

Using your modified wifi-simple-adhoc-grid.cc to run the following simulations.

Set the source node as the node 6 and the sink node as node 7. Run the simulation repetitively with the distance between two neighbor nodes (i.e., distance in the script) increasing from 500 to 800, with a 60 increase in each step. In each running, you need to let the source send out 20 packets. Measure the number of received packets in the sink in each run. Draw the result as a figure in which x-axis is the value of distance and the y-axis is the number of received packets.

Do the same experiment as in the above but from node 0 to node 24.

Write a report for the experiment

Please include the two figures resulted from step 3. Please introduce whether there are any differences between the two figures. If yes, explain the reason for the differences. If no, please also explain why we get identical result in the experiment with two sets of nodes.

Find the route from node 22 to node 2 from the route trace