To specify number portability between Service Provider (SP) i.e. a customer moving from one pan-European ETNS Service Provider (SP) to another and retaining a European Number for that service.
Digital cellular telecommunications system (Phase 2+) (GSM); Universal Mobile Telecommunications System (UMTS); LTE; Mobility management based on Mobile IPv4; User Equipment (UE) - foreign agent interface; Stage 3 (3GPP TS 24.304 version 16.0.0 Release 16)