Our Simulation


IEEE 802.11 
      Network Simulator 
Our Simulation 




Simulation 1. (Simple Wireless Network)

  • Two fixed nodes
  • moving within 600m x 600m flat topology
  • DSR ad hoc routing
  • TCP and CBR traffic
  • Receiver move in and out of range

       This model is working based on IEEE 802.11 MAC protocol.  We set the routing protocol to DSDV (Destination-Sequenced Distance-Vector, LinkLayer type to LL, the interface queue type to Queue/DropTail/PriQueue, physical type to a wireless network interface, and channel type to a wireless channel.  The topography for this simulation is set to a 600*600 flat grid and there are two nodes.  The distance between two nodes is 200m.  In this simulation, we can see both cases of when two nodes are in transmission range and out of the transmission range.

Download simple_wireless.tcl            

Simulation 2. (4 nodes)

  • Two fixed pairs (4 nodes)
  • moving within 800m x 800m flat topology
  • AODV ad hoc routing
  • TCP and CBR traffic
  • 2 nodes in each pair communicate each other (hidden node)

In this simulation, we can see the effectiveness of RTS/CTS handshake(Collision avoidance mechanism in ad hoc wireless LAN). However, even if RTS/CTS signals are exchanged between the nodes, transmitting nodes can interfere the other transmitting nodes.

Download 4node.tcl            

Simulation 3. ( Packet Size received depending on Routing protocols

  • Six fixed nodes
  • Change Routing algorithm
  • 4 Ad hoc routing: DSR/ DSDV/ AODV/ TORA
  • The left-most node sends data to the right-most node



        While node 0 sends packets to node 3, node 2 try to send packets to node 1. In this case, depending on the routing protocols, the packets received in node 1 and node 3, is changed. In our simulation, we selected 4 different ways to route: DSDV, TORA, DSR, and AODV.


       Two of the more popular routing protocols are DSR and AODV. Both of these are reactive protocols, which mean that they wait until the node wants to send data to another node before trying to find a route to it. The largest difference is that DST finds the complete path to the destination and includes it in each data packet while AODV nodes only know about which neighbor to forward packets to for each destination. This and other properties of these protocols, have the effect that DSR requires more overhead when sending data and AODV requires more overhead for discovering routes. In the network simulator offer DSR, AODV, TORA, and DSDV routing protocols for the wireless network.

       You can see the difference between these routing protocols through below files. When the routing protocol is DSR, node 0 sends packets to node 3 through node 1 and node2.  That's why when node 2 tries to send packets to node 1, it can't send packets because node 1 is busy. However, in the case of AODV, node 0 sends packets to node 3 only through node 2.

Download files here.(dsr.tcl, aodv.tcl, tora.tcl, dsdv.tcl)


Copyright(c) 2002. All rights reserved.
faithink@bu.edu, kimsooil@bu.edu