 that location of a base station on another operator's cell border gives the worst case. Consequently, site sharing with other operators in WCDMA will be imperative. In conclusion, about 35- 40 dB ACP gives a worst case capacity loss of 5-10% for the worst case located base stations. In UTRA, e.g. FDD the nominal carrier spacing of 5.0 MHz can get adjusted in steps of 200 kHz according to the needs of the adjacent channel interference. Figure 8.8 illus- trates this possibility. Minimized interference Operator A Operator B ~4.xMHz >5.0MHz ~4.xMHz Figure 8.8 Carrier spacing example between operators. Therefore, the process of optimizing the network to minimize ACIR may involve maximum site sharing between operators, a dynamic adjustment of the carrier spacings within a network as well as inter-networks, de-sensitization of the BS receiver, inter- frequency handovers when excess ACIR occurs, and ideal antenna location or co- location. 8.4.2 Enhancing and Managing Capacity Efficient network dimensioning and optimized BS deployment will complement a very good admission control system to manage and maximize capacity successfully. Admission control has to do much with the RNC to maintain the requested quality of service of the radio links. It monitors the load (i.e. downlink power and UL interference level) on the cell carrier. RNC functions desiring to allocate radio resources on given The UMTS Network and Radio Access Technology cell carrier request to the admission control for the target cell resources. The functions triggering the admission control tasks may include: signalling connection setup (allocating for radio resources administration) soft/softer HO intersystem HO (e.g. GSM to UMTS or vice verse) radio link co-ordination (i.e. setting up radio resources) channel type switching/selection (e.g. common to dedicated channel) paging code allocation/re-allocation The admission control also prioritizes depending on the type of calls, e.g. emergency calls will precede a normal (voice or data) call. System control tas