The present document specifies the Digital Enhanced Cordless Telecommunications (DECT) access protocols and Fixed Part (FP) and Portable Part (PP) interworking/mappings necessary to ensure that the Universal Mobile Telecommunication System (UMTS) services can be provided over DECT. To enable DECT terminals to interwork with DECT systems which are connected to the UMTS infrastructure@ from the DECT side of the present document is based on EN 300 444 [10] and on the DECT Common Interface specification EN 300 175 parts 1 [1] to 8 [8] (for the cases not covered by Generic Access Profile (GAP))@ from UMTS side the present document assumes interworking with UMTS specification release 1999+. An air-interface profile is specified for a particular set of UMTS services so that inter-operability of DECT equipment for these services can be achieved. Interworking functions/mappings are specified for Mobile Switching Centre (MSC attachment for the DECT FP as the FP is using the Iu-interface towards the UMTS core network in the respect that the FP emulates a UTRAN Radio Network Controller (RNC) with regards to the UTRAN messages which are relevant to the present document. Interworking functions/mappings for the PP are specified for MSC environment. The provision of the (UMTS) Subscriber IdentityModule (SIM@ USIM) and DECT Authentication Module (DAM) within the DECT portable are also considered. UMTS interfaces to non-UMTS networks are out of the scope of the present document.