or CS 2G/3G services in seamless co-existence. Furthermore, some 3GMSCs will interconnect through IP interfaces and multiplex Iu traffic from the RNC. 3.2.4.1.1 ATM Functionality For all practical purposes we assume here that the ATM functionality takes place in a dedicated element, which we will call the ATM unit. This unit will have as a primary function to provide inter-working of the 3GMSC with the UMTS Radio Access Net- work (UTRAN) In most cases this unit will also provide transcoding functions for 3G CS services. The ATM unit will then support: Iu interface for ATM transmission in the UTRAN side and TDM transmission in the MSC side speech transcoding and user plane adaptation for CS data services 3G to 2G protocol conversion (e.g. WCDMA RANAP and GSM BSSAP). 3.2.4.2 The 3G Home Location Register In most cases the 3GHLR will evolve from the 2GHLR through SW upgrade, i.e. the same HLR (including e.g. AuC and EIR) will serve 2G/3G dual-mode users with cen- tralized subscriber information. Thus, service providers will use only one centre to acti- vate 2G subscribers (e.g. GSM voice or GPRS) and UMTS subscribers with all their different traffic profiles. The 3GHLR then stores: subscriber profile data for 2G and 3G services subscriber identity semi-dynamic information, e.g. current subscriber profile with activated ser- vices, etc. dynamic data, e.g. mobility management data. authentication information equipment identity info specifying listed mobile equipment identities. 3.2.4.3 New Services While expected CS services may have rates up to 384 kbps, initial new services may start first with 64 and 144 kbps. Among these services sets we will have, e.g.: Virtual Home Environment (VHE): comprehensive set of services, features and tools, which have the same look and feel at home or abroad new bearer service defined by QoS parameters and a toolbox for implementing operator specific services The UMTS Network and Radio Access Technology roaming between 2G/3G network, i.e. UMTS and GSM will be supported as well as hando