uplink interference has a great impact on the cell capacity and radius. The interference margin (n) indicates the total amount of interference (including thermal noise power) in comparison to the thermal noise: (2.54) where Eb/No = signal energy per bit/noise spectral density N = total number of users/cell R = bit rate W = chip rate i = other cell-to-own cell interference Uj = activity factor of user j Downlink In the downlink, the power transmitted by the BS is shared between all users. The capacity is determined by the power transmitted by the BS, locations of UE and interference. Thus, the parameters needed for downlink calculations include the power transmitted by BS and power allocation to the Common Control Radio Network Planning and Optimisation Channel (CCCH). Thus, in downlink the capacity is determined by the power transmitted by the BS, locations of UE and interference. This makes the calculations in downlink more complicated than the uplink directions, for in the uplink each user has its own amplifier to transmit the power. Thus, coverage becomes a function of the number of users. In DL the own cell interference is reduced by the factor (1 - a). This is due to the synchronised orthogonal channellisation codes, which are used in DL. The downlink load factor can be calculated as (2.55) where (2.56) and the orthogonality factor aj is between 0.4 and 0.9 (the ITU vehicular subscriber for the macro cell is 0.6 and the ITU pedestrian subscriber for the micro cell is 0.9). In the WCDMA system, the traffic can be asymmetric in the uplink and downlink directions and thus the load can also be different in either direction. The DL load is, however, higher than the UL load. The link performance also differs in either direction (the noise figure is higher for the UE than the BS). Soft handover heads are only in the DL direction. The load factor for different services has to be calculated separately. The total load is then the sum of different services in the cell area. Soft Capacity The principle of soft capacity 