Return on Investment (roi) for Multi-Technology son juan Ramiro, Mark Austin and Khalid Hamied

UE₁ UE_n
Figure B.1 Overview of the X-map estimation approaches.
calculated. In areas where no measurement data can be taken, e.g. due to coverage holes, no information is available in the corresponding part of the X-map.
In approach 2, the X-map is based on prediction data created by means of a propagation model which is adapted to the environment of the corresponding eNodeB with the help of the provided measurement data. In the presented simulations, the Okumura-Hata model [7] is used and correction factors are calculated for the considered land use classes based on the collected measurement data. This is part of the calibration method described in [8] and similar to the method introduced in [9]. By calibrating the correction factors per land use class, the accuracy of the Okumura-Hata model can be improved.

B.3. Simulation Results

For simulating the two approaches, a scenario of 1.5 km × 1.5 km in an urban area is used [10]. In this scenario, 20 users move along the streets and send measurement reports every 200 ms to their serving eNodeBs during a simulation time of 1000 s. For the LTE network, the site locations, sector orientations and antenna tilts are taken from an existing UMTS layout. For these sites, realistic path loss predictions at 2.6 GHz are available. These predictions are used to determine the 30 strongest cells for each user position. Furthermore, the predictions serve as a reference for determining the accuracy of the resulting X-maps (in terms of mean error and standard deviation) by comparing every pixel with a valid RSRP value in the X-map with the corresponding pixel of the prediction. For the simulation area, land use data is derived from the freely available information provided by the OpenStreetMap project [http://www. openstreetmap.org]. Five different land use classes are distinguished, namely, buildings, natural areas, waterways, streets and railways. Furthermore, satellite orbits for a specific date