---------------------------------------------- TrueTime 1.5 Example: Wireless Ad-hoc Routing Using AODV Directory: $DIR/examples/AODV----------------------------------------------1. INTRODUCTIONThis example describes a TrueTime implementation of the Ad-hoc On-Demand Distance Vector (AODV) routing protocol. See the TrueTime reference manual for a more comprehensive description of the exampleand for references to AODV documentation.2. COMPILING THE SIMULATION FILES2.1 Configuring the TrueTime Environment    Before starting Matlab, you must set the environment variable    TTKERNEL to point to the directory with the TrueTime kernel files:        Unix/Linux: > export TTKERNEL=$DIR/kernel        Windows:  Control Panel / System / Advanced / Environment Variables    Then add the following lines to your MATLAB startup script. This    will set up all necessary paths to the TrueTime kernel files.        addpath(getenv('TTKERNEL'))        init_truetime;2.2 Compilation    As described in the reference manual it is possible to write a    TrueTime simulation (i.e. the code functions for the tasks and the    initialization commands) either as m-files or as C++ functions. For    this example only the m-file approach is provided.    Since the TrueTime archive contains pre-compiled files, no     compilation is required to run TrueTime in the Matlab version.     However, if needed, the files may be re-compiled by issuing the     command make_truetime from the command prompt.3. SIMULATIONSOpen the model AODV.mdl to run the simulation. - The simulation example consists of seven nodes. Choose the option  Update Diagram in the Edit menu to bring up an animation window of  the simulation. This will show the original positions of the seven  nodes and their respective signal reach.- Run a simulation. In the simulation scenario, the left-most node  (node 1) sends data periodically to node 7 with period 0.5.  The initial route that is established is 1 -> 3 -> 5 -> 7. At time   t=3, node 5 starts to move which eventually leads to the route breaking.   At time t=10, node 6 repairs the route by moving in between node 4  and 7. The printouts in the Matlab command window describe the actions   in the AODV layer in more detail. Also study the global variable  routing_table. - Open and examine the file initsim.m. This file initializes the global   variables used in the simulation, e.g., the routing table and the node   positions. By changing the variable verbose from 0 to 1 even more   detailed AODV information will be displayed when the simulation is run.- The global variables sent and received show the data that is sent  (by node 1) and received (by node 7) in the simulation. Examine the   lengths of these vectors to determine how many messages that where lost   due to the delay in detecting and propagating the information about the   broken link back to the source node. (Answer: The messages sent at times   8.0002, 8.5002, and 9.0002 are lost.)- The hello interval determines how fast the network will respond  to broken links (and also the bandwidth overhead). Try changing the  AODV parameter HELLO_INTERVAL (both in initsim.m and node_init.m) to   decrease the number of lost data messages. In this case only two messages   are lost.