ENUM-based number portability for 4G/5G mobile communications

Abstract

With the evolution of the core network, providing multimedia services is much easier in the all-IP packet-switched networks than that in the circuit-switched networks. In the 4G/5G core network, the IP Multimedia Subsystem (IMS) is widely deployed to provide multimedia services such as Voice over LTE (VoLTE). To provide a fair-competition environment for the mobile operators, the Number Portability (NP) service should be defined in the 4G/5G specifications. However, the up-to-date specifications only indicate that the E.164 NUmber Mapping (ENUM) can be used for the NP service but do not propose the detail message flows and the major parameters. Moreover, the NP scenarios in the IMS networks are different from those in the Public Switched Telephone Networks (PSTNs). To provide the NP service in 4G/5G, this paper proposes an ENUM-based NP service where the message flows and the major parameters are designed based on the IMS architecture.