Section: New Results

Network simulation tools

Several works in 2011 have been using simulation results. Nevertheless, Swing members are strongly working on improving network simulation frameworks to provide realistic simulations. Several contributions to the simulation tools wiplan ans wsnets have been proposed.

Some contributions to WSnet concern BAN environments implementation [44] and network coding features [19] , [81] . Different protocols have been also implemented for wireless sensor networks [34] , [84] , specifically in the context of our collaboration with Orange Labs, Grenoble.

The wiplan simulator has been developed at CITI for several years. It is based of a frequency domain ParFlow (MR-FDPF) implementation that represents a unique finite elements based method for estimating the radio propagation in complex environments. In the context of heterogeneous networks, femtocells are very promising. In order to properly simulate their behavior and their impact on the macrocell layer, it is necessary to be able to simulate the radio coverage of femtocells. Hence ParFlow is a possible deterministic model that can be used for such simulation. In [42] , two implementations of ParFlow are presented: time domain and frequency domain. The performance are compared and the advantages/drawbacks of each model are investigated.

In [56] we propose to use finite difference propagation methods to evaluate the wide band properties of the fast fading. For this purpose we adapted the MR-FDPF propagation model to simulate large bandwidth by combining numerous narrow band simulations. The results are compared with a channel sounder measurement campaign covering a bandwidth of up to 70 MHz. It is verified that fading characteristics in wireless channels varies with frequency and the MR-FDPF method is capable for simulating this variation of fadings for wide band systems.

In [56] , a new approach is proposed allowing extracting the fading statistics for indoor radio channels based on the electric field strength predicted with the MR-FDPF method. The performance of the proposed approach is verified both by simulations and measurements.

In [65] , we propose a new hybrid modeling method for indoor-to-outdoor radio coverage prediction. The proposed method is a combination of a ray-optical channel modeling approach and the frequency domain ParFlow method. While the former is widely used for modeling outdoor propagation environments, the latter is computationally efficient and accurate for modeling indoor environments.

In [90] , we propose to use finite difference propagation methods to evaluate the wide band properties of the fast fading. For this purpose we adapted the MR-FDPF propagation model to simulate large bandwidth by combining numerous narrow band simulations. The results are compared with a channel sounder measurement campaign covering a bandwidth of up to 70 MHz. It is verified that fading characteristics in wireless channels varies with frequency and the MR-FDPF method is capable for simulating this variation of fading for wide band systems.