e planning has to be done carefully and with the highest rigour. For this, the BCCH and TCH bands are separated. Moreover, depending on the network topology, the BCCH band can be split between different site configurations. For example, in an area where a lot of hotspot micro cells are deployed, and since micro cell and macro cell propagation mechanisms are different, it is judicious to separate spectra for the two layers. The opposite occurs for a non-micro-dense area, as the same band can be reserved for both layers with a higher priority for macro and umbrella sites. The BCCH strategy also depends on whether synthesised frequency hopping is used or not. When SFH is used, a longer band can be allocated to the BCCH because the TCH layer uses MAList (mobile allocation list) random attribution (interference diversity). There are two main possible ways for frequency planning: manual and automatic. This subsection deals with the manual method and the later subsection on automation tools approaches deals using the automated way. The manual method is especially justified when the network is well designed (small intersite distances, regular trisectorisation, homogeneous antennas and BTSs). Most European operators use the 7 X 21 model, which means distribution of 21 frequencies identically configured on areas of seven sites (see Figure 2.50). In this case, notice that channels 1 to 22 are used except 19 in order to avoid an adjacency interference with channel 18. For zones where it is difficult to apply this model without generating interference (relief, sea cost, high sites, sites with nonstandard azimuths, etc.), it is recommended that some additional joker channels should be raserved in order to tune sites manually. This hexagonal motif seems to give good results in theory and also in practice through several project experiences. Manual corrections should, however, be done according to field constraints/knowledge and planning tool-simulated interferences. Theoretically speaking, if it is assumed in an urban area that