Scenario
- 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
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Scenario
- 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
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Scenario
- 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.
Discussion:
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)
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