4 . 5 Propagation Modeis for Small - and Micro - Cells

The design and implementation of personal communications systems requires the prediction of wave propagation relating to signal-to-noise and signal-to-interference calculation in a cellular system [93]. Small-cell network configurations especially microand pico-cell types are of major interest for urban environments. The commonly used criteria for the definition of a micro-cell is related to the base-station height. For a typical micro-cell the base-station antenna height is below the average roof-top level of the surrounding buildings or at about the same height. Thus the resulting cell radius is in the range of about 250-500 m. However a prediction range of up to several km has to be regarded for inter-cellular interference calculations. A pico-cell base-station is usually installed inside a building providing coverage also outside around the building. A tutorial and overview on wave propagation modeIling for wireless personal communications is given in [94].