Simulation VirtualMesh: an emulation framework for wireless mesh and ad hoc networks in

Wireless Mesh Networks (WMNs) have proven to be a key technology for increased network coverage of Internet infrastructures. The development process for new WMN protocols and architectures is typically split into evaluation by network simulation and testing of a prototype in a test-bed. Testing in simulation often requires the developer to write software that is not directly portable to test-beds, whereas pure prototype testing on real hardware is time consuming and expensive. Irrepressible external interferences can occur, which make debugging difficult. Moreover, the test-bed usually supports only a limited number of test topologies and sites. Finally, mobility tests are impractical. Therefore, we propose VirtualMesh as a novel testing architecture, which can be used before evaluating in a real test-bed. It provides instruments to test the real communication software, including the network stack inside a controlled environment. VirtualMesh has been implemented by capturing real traffic through a virtual interface at the mesh nodes. The traffic is then redirected to the network simulator OMNeTþþ. In our experiments, VirtualMesh has proven to be scalable, to have minimal influence on throughput and to introduce only negligible delays (less than 0.4 ms per hop). Hence, it is a valuable tool for protocol and application developers to test their software prior to the final deployment. Keywords integration of real nodes in a simulated environment, network emulation, network simulation, OMNeTþþ, pre-deployment testing, wireless emulation 1