A Virtual WLAN Device Model for High-Fidelity Wireless Network Emulation

The recent popularization of mobile devices has increased the amount of communication traffic. Hence, it is necessary both in academia and industry to research load distribution methods for mobile networks. An evaluation environment for large-scale networks that behaves like a practical system is necessary to evaluate these methods, and either a physical environment or simulation environment can be used. However, physical and simulation environments each have their advantages and disadvantages. A physical environment is suitable for practical operation because it is possible to obtain data from a real environment. In contrast, the cost for a large number of nodes and the difficulty of field preparation are its disadvantages. Reproducing radio propagation is also a challenge. Network simulators solve the disadvantages of the physical environment by modeling the entire evaluation environment. However, they do not exactly reproduce the physical environment because the nodes are abstracted. This article presents an evaluation environment that combines a network simulator and virtual machines with virtual wireless Local Area Network (LAN) devices. The virtual machines reproduce the physical environment with high fidelity by running the programs of the physical machines, and the virtual wireless LAN devices make it possible to emulate wireless LAN communication using default operating system drivers. A network simulator and virtual machines also reduce the cost for nodes, ease the burden of field preparation, and reproduce radio propagation by modeling the evaluation environment. In the evaluation, the proposed method decreased the difference from the physical environment to 5% in terms of transmission control protocol throughput. In the case of user datagram protocol, the proposed method decreased the difference from the physical environment down to 1.7%. The number of virtual machines available on a host machine and the practical use of the proposed method are also discussed.