Hi there, some thoughts on setting simulation paramerters. I hope they will be helpful for you even though my answer is not a direct answer to your questions.
1. you want to compare "performance". Therefore, it is necessary that you spend some thought on what you define as "performance". System throughput? Single user throughput? HTTP response time for single users? Average/min/max of these? Number of route changes? Time for route discovery? Number of hops for a given route? Degree of connectednes in the network? etc. Basically, "performance" can only be measured by performance indicators and many of the above mentioned things trade-off on each other. Eg. if you change something in the system and it improves eg. HTTP response times for single users this change might degrade system response time at the same time. So you need to define exactly what is important for you and how far you want to trade-off. Eg. if you can improve HTTP response times by x% you are willing to accept a degradation of system throughput of y%. Hopefully you find a method so that x > y ;-) 2. when you have defined your performance goal you can start to think about how to test for it. Eg. if you know that one of your protocols is better for dense networks and one is better in sparse networks then you should vary the density of the network and eg. check whether oen protocol covers a wider variety of situations, if there is any overlap and how they compare in the overlap region, etc. For this you should check existing literature to know the features of the protocols beforehand pretty well. These two steps are really important, otherwise you will waste lots of time with mindless simulation. 3. Examples: Are you sure why you chose 10 source/destination pairs? Should you vary this number? How do you expect that this number will affect the two protocols you want to compare? Same goes for the number of 50 nodes in total. Why is the topology 1500x300? btw: 1500x300 what? meters? feet? Is 50 nodes on a 1500x300 (lets assume m^2) topology considered dense or sparse for the protocols you want to investigate? What does the literature suggest? The topo is only 300m wide but 1500m long. Have you thought about how you are going to generate the positions of the nodes (in theory)? I expect that you want to distribute them "uniformly". Are you just generating x and y positions with x~uniform and y~uniform? This would result in a higher density of the nodes in one direction over the other. Is that really what you want for "uniform"? 4. some practical hints: I usually write generation scripts in tcl with which I generate the position and movement files myself before the simulation itself. I then save the position and movement files and use them for each of the simulations where I want to change eg. just the traffic but not the movement pattern. In this way I get reproducability. If you just generate the movement on-the-fly and don't save it to a file you can never re-run a simulation. eg. I make a script called generator.tcl which takes eg. number of nodes (say, 50) and topology (say, 1500x300) size as input and generates (with print to file) a file, say n-50-t-1500-300.scen . This is just a text file which contains tcl commands to set the x and y positions of the nodes and the tcl commands to set up the topology. In the same way I can generate a matching movement file which contains movement commands in tcl. In this way, I can try several different movement patterns on the same initial topology. Later on I source these files in my main simulation script. I usually run several runs of the simulation driven by a shell script overnight or over the weekend. The shell script can give parameters to the simulation script and depending on these parameters I can load the corresponding scenario and movement files. Not only that, the shell script can also make sure that any missing scenario files are generated before the simulation is run. After the simulation runs I usually automatically do some pre-processing of the trace files to save disk space. And, of course, I can run many simulations with different settings for the random generator. So the next morning I can have the results for say, 20, 50, and 100 nodes in the same topology, all averaged over 30 simulation runs each. good luck, Martina Umlauft vitz399 schrieb: > > Hello everybody. > > I have a write a report about the performance comparison between AODV and > DSR. Now, I have to setup a simulation environment for both AODV and DSR > protocols. But I have no idea how could I configure the parameters for > simulations. Here is the initial parameters for the simulations: > > 10 source/destination pairs for a > 1500x300 network of > 50 nodes. > > The source should be generating traffic at 2 packets per second (period of > 0.5s). > > And the mobility should be simulated by generating scenario scripts. Do I > use setdest for this? > > Could anyone kindly give me a simple template or guidelines to where and how > to set up those parameters in a simulation script file. > > Many many thanks in advance, > > regards, > vitz
