co-located sites). The UMTS Network and Radio Access Technology 5.5.1.4 Macro to Micro Multi-Operator Case 5.5.1.4.1 Single Operator Layout, Micro Cell Layer For the micro-cell deployment in a Manhattan deployment scenario we place the BSs SO that they stand at street crossings in every second junction as illustrated in Figure 5.7 [6]. Although the model does not reflect efficient planning, it does provide sufficient amount of inter cell interference generation with reasonably low number of micro cell BSs. The parameters of the micro cells are thus: block size = 75 m, road width = 15 m, inter-site distance between line of sight = 180 m, and the number of micro cells in the micro-cellular scenario is 72. Figure 5.7 Micro-cell deployment. 5.5.1.4.2 Multi-Operator Layout In this micro cell layout we use the parameters proposed earlier, i.e. (72 BSs in every second street junction, block size 75 m, road width 15 m). We also apply a macro cell radius of 577 m with a distance of 1000 between BSs. Figure 5.8 illustrates the cellular layout to simulate Hierarchical Cell Structures (HCS). This layout allows large enough macro cells and a low number of micro cells SO that computing simulation times remain reasonable. Furthermore, we select macro cell BS positions to observe handovers and many other conditions (e.g. border conditions, etc.). The UTRA Transmission System Figure 5.8 Macro-to micro deployment. When measuring interference at macro cell BSs in uplink, we measure same channel interference only from those users connected to the observed BS. Then we multiply the measured same channel interference by 1/F, where F is the ratio of intra-cell interfer- ence to total interference, i.e. (5.2) F depends on the assumed propagation model; earlier studies suggest a typical value of around 0.6. However, an appropriate value for F can also be derived from specific macro cell only simulations. We measure interference from micro cells to macro cell by using the wraparound technique. We can then define the interference that a mac