nd the PS traffic servers (SGSN servers and GGSN nodes). It stores subscriber data down- loaded to the nodes, from a domain where a subscriber presently roams. 8.3.4.3 Conclusions In the preceding sections, we have outlined mainly the types of 3G functions that an integrated NMS will have to capture. Thus, we assume that a new 3G NMS will incor- porate the typical 2G functions from GSM systems, for example, and seamlessly inte- grate them into its control mechanism. Many of the 3G logical functions will have the same operation principle as that of the 2G. However, the separation of the control and users planes will bring a new dimension to managing a network. UMTS NETWORK OPTIMIZATION Network optimization will depend on the operating environment, the loads for which we design the network, and the appropriated allocation of resources. The operating environment cannot neglect interference from adjacent networks, assum- ing the internal network interference is under control. Thus, in the following before we address or review capacity or load enhancing options, and efficient ways to allocate resources, we deal briefly with multi-operator interference issues. To maximize the performance of the FDD (i.e. WCDMA) system, we need a minimum spectrum mask for a transmitter and highest selectivity for a receiver in the MS and BS, in order to minimize adjacent channel interference. In this context, we define the Adja- The UMTS Network and Radio Access Technology cent Channel Interference Power Ratio (ACIR) as the ratio of the transmission power to the power measured after a receiver filter in the adjacent channel(s). Where we measure both the transmitted and the received power with a root-raised cosine filter response with roll-off 0.22 and a bandwidth equal to the chip rate as described in Chapter 4. ACIR occurs due to imperfect receiver filtering and a non-ideal transmitter. In the UL we get ACIR from the non-linearities of the MS power amplifier, where inter- modulation originates adjacent to channel leakage power. In the 