Section: 5.1.2.2 Legacy service support
Content: In principle, the 5G system shall support all EPS capabilities (e.g. from TSs 22.011, 22.101, 22.278, 22.185, 22.071, 22.115, 22.153, 22.173, 22.468). However, - voice service continuity from NG-RAN to GERAN shall not be supported, - voice service continuity from NG-RAN to UTRAN CS should be supported (see Note), - voice service continuity from GERAN to NG-RAN shall not be supported, - voice service continuity from UTRAN to NG-RAN shall not be supported, - CS fallback from NG-RAN to GERAN shall not be supported, - CS fallback from NG-RAN to UTRAN shall not be supported, - seamless handover between NG-RAN and GERAN shall not be supported, - seamless handover between NG-RAN and UTRAN shall not be supported, - access to a 5G core network via GERAN or UTRAN shall not be supported, - video service continuity between 5GS and UMTS shall not be supported, - IP address preservation for PS service when UE moves between 5GS and GSM/UMTS shall not be supported, and - Service continuity between 5GS and CDMA2000 shall not be supported. NOTE: Architectural or protocol changes needed to support voice service continuity from NG-RAN to UTRAN CS are expected to have minimum impact on architecture, specifications, or the development of the 5G New Core and New Radio.