Enabling Multicast and Broadcast in the 5G Core for Converged Fixed and Mobile Networks

The fifth generation of cellular technologies, 5G, promises to deliver a wide variety of services. However, the first release of 5G (3GPP Rel-15) did not consider multicast capabilities in the 5G system including both access and core networks. This article fills the gap by describing solutions for 5G mobile core network architecture incorporating multicast and broadcast capabilities. Two innovative solutions to provision multicast and broadcast, based on 3GPP Rel-15 arechitecture, have been proposed and analyzed. One is 5G architecture friendly with low imprint over Rel-15 while the other is based on the evolution of LTE Broadcast architecture. The architectural solutions feature two new main transmission modes: transparent multicast transport and point-to-multipoint services. The former enables the 5G network as a network pipe supporting multicast traffic providing a cost-effective delivery mode for multimedia while the latter enables multicast and broadcast as a service. The paper also presents a convergent fixed wireline and mobile network architecture based on the proposed mobile network architecture altenatives. The proposed architecture alternatives are suitable for different verticals and applications such as Digital Terrestrial Television, Public Warning, Internet of Things, V2X (vehicle to everything) and mission critical communications (MCC).

I. Introduction

The first 3GPP release of 5G technology (Release 15 or Rel-15), also known as 5G NR (New Radio), was completed in 2018. Rel-15 was structured in three phases. The first phase addressed a non-standalone (NSA) version that requires LTE EPC (Evolved Packet Core) for the control plane (CP). It introduced 5G NR to enhance the user plane (UP) performance and efficiency using dual connectivity across the LTE and NR bands. In the second phase, the stand-alone (SA) version of 5G was standardized, including the 5G core network (5GC), that enabled deployments without any LTE infrastructure. The last phase enabled more architecture options for hybrid LTE and 5G NR deployments using the 5GC. It enabled using the 5GC to inter-work with both LTE RAN (Radio Access Network) and NG-RAN (Next Generation RAN), using the NG-RAN for the control plane.