Implementation and Validation of a New Combined Model for Outdoor to Indoor Radio Coverage Predictions

Guillaume De La Roche,Guillaume Villemaud,Paul Flipo,Zhihua Lai,Jean-Marie Gorce,Jie Zhang

doi:10.1155/2010/215352

Abstract

A new model used to compute the outdoor to indoor signal strength emitted from an outdoor base station is presented. This model is based on the combination of 2 existing models: IRLA (Intelligent Ray Launching), a 3D Ray Optical model especially optimized for outdoor predictions, and MR-FDPF (Multiresolution Frequency Domain ParFlow), a 2D Finite Difference model initially implemented for indoor propagation. The combination of these models implies the conversion of the ray launching paths on the border of the buildings, into virtual source flows that will be used as input for the indoor model. The performance of the new combined model is evaluated via measurements at 2 frequencies (WiMAX and WiFi). This solution appears to be efficient for radio network planning, in term of both accuracy and computational cost.

Highlights

Indoor networks planning is increasingly important; that is why tools have been developed to help operators to optimize their networks
The simulated signal inside the CITI building based on the new combined model is plotted in Figure 5 (Experiment 1) and Figure 6 (Experiment 2), as well as the comparison between simulation and measurements for the received signals
In order to evaluate the accuracy of the model more in details, the RMSE values as well as the ME are plotted in Table 3, depending on if MR-FDPF is calibrated, and depending on the number of points used for the calibration

Summary

Introduction

Indoor networks planning is increasingly important; that is why tools have been developed to help operators to optimize their networks. Such tools are necessary to find the best parameters like the positions of the emitters, the optimal radiated power, and the best channels. Attention has been given to optimizing the indoor radio coverage by using specific indoor solutions such as Femtocells [1] Such femtocells are deployed directly inside buildings, efficiently enhancing both the indoor radio capacity and coverage. Accurate outdoor to indoor propagation tools, that are able to compute the in-building signal due to outdoor cells, are currently highly demanded by mobile operators. The aim of this paper is to propose a new combined propagation model, which could be a good approah for this purpose

Objectives

Results

Conclusion