Key Issue Analysis on 5G Inter-networks Roaming

There is an increasing demand for cost-effective deployment of 5G network during radically generational change. Various solutions are proposed to address co-construction and network sharing issues, including an emerging technology of 5G inter-networks roaming. In this paper, new business scenarios are specially clarified in comparison with international roaming with respect to scope of application, service experience and commercial secret protection. Furthermore, five key issues concerning 5G inter-networks roaming are examined and corresponding solutions are introduced to settle problems that may arise. To address service experience problems in bidirectional mobility scenarios between a non-roaming area and a roaming area, data and voice service continuity solutions with inter-networks N14 and N26 interfaces enabled are proposed. Besides, problems of emergency call compatibility are proposed to be resolved by switching to common call procedure with adaptation of UE and 5GC emergency capabilities. Finally, optimization of signaling procedure with enhanced transformation feature on SEPP and a novel Number Masking Function are collectively proposed to conceal operators' sensitive information including IP address, port number, FQDN and GPSI number.