WiFra is a new framework for the detailed simulation of very large-scale wireless networks. It is based on the parallel and distributed simulation approach and provides high scalability in terms of size of simulated networks and number of execution units running the simulation. In order to improve the performance of distributed simulation, additional techniques are proposed. Their aim is to reduce the communication overhead and to maintain a good level of load-balancing. Simulation architectures composed of low-cost Commercial-Off-The-Shelf (COTS) hardware are specifically supported by WiFra. The framework dynamically reconfigures the simulation, taking care of the performance of each part of the execution architecture and dealing with unpredictable fluctuations of the available computation power and communication load on the single execution units. A fine-grained model of the 802.11 DCF protocol has been used for the performance evaluation of the proposed framework. The results demonstrate that the distributed approach is suitable for the detailed simulation of very-large scale wireless networks.

1. Gabriele D’Angelo joint work with Michele Bracuto University of Bologna Department of Computer Science DS-RT 2007 – Crete Island (Greece) Detailed Simulation of Large-Scale Wireless Networks

15. Experimental evaluation Wireless model parameters Simulation time-step 10 μs (802.11 SIFS) MAC layer IEEE 802.11 DCF Packet size 1024 bytes Packet rate 4 pkt/s Propagation model Transmission range Free space propagation 250 meters Simulated area Variable size Fixed density of nodes Nominal channel bit rate 2 Mbps Mobility model Random WayPoint (RWP) Simulated devices (SMHs) 200.000, 1.000.000

16. Experimental evaluation: distributed simulation environment 200.000 SMHs. 1 up to 8 PEUs: Dual Core Intel Pentium IV CPU 3.0 GHz with 1GB of RAM, interconnected by Fast Ethernet

17. Experimental evaluation: GAIA+ ON/OFF

19. Experimental evaluation: massively populated scenario

20. Experimental evaluation: massively populated scenario The gain in terms of performance is up to 21% More complex user level protocols would increase this gain

22. Gabriele D’Angelo joint work with Michele Bracuto University of Bologna Department of Computer Science DS-RT 2007 – Crete Island (Greece) Detailed Simulation of Large-Scale Wireless Networks