The 3rd Generation Partnership Project (3GPP) has defined based on the Long Term Evolution (LTE) enhanced Multicast Broadcast Multimedia Service (eMBMS) a set of new features to support the distribution of Terrestrial Broadcast services in Release 14. On the other hand, a new 5th Generation (5G) system architecture and radio access technology, 5G New Radio (NR), are being standardised from Release 15 onwards, which so far have only focused on unicast connectivity. This may change in Release 17 given a new Work Item set to specify basic Radio Access Network (RAN) functionalities for the provision of multicast/broadcast communications for NR. This work initially excludes some of the functionalities originally supported for Terrestrial Broadcast services under LTE e.g. free to air, receive-only mode, large-area single frequency networks, etc. This paper proposes an enhanced Next Generation RAN architecture based on 3GPP Release 15 with a series of architectural and functional enhancements, to support an efficient, flexible and dynamic selection between unicast and multicast/broadcast transmission modes and also the delivery of Terrestrial Broadcast services. The paper elaborates on the Cloud-RAN based architecture and proposes new concepts such as the RAN Broadcast/Multicast Areas that allows a more flexible deployment in comparison to eMBMS. High-level assessment methodologies including complexity analysis and inspection are used to evaluate the feasibility of the proposed architecture design and compare it with the 3GPP architectural requirements.

中文翻译：

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地面广播业务的 5G 无线接入网络架构

第三代合作伙伴计划 (3GPP) 基于长期演进 (LTE) 增强型组播广播多媒体服务 (eMBMS) 定义了一组新功能，以支持第 14 版中的地面广播服务分发。从第 15 版开始，新的第 5 代 (5G) 系统架构和无线电接入技术 5G 新无线电 (NR) 正在标准化，迄今为止仅关注单播连接。考虑到新的工作项集，这可能会在第 17 版中更改，以指定用于为 NR 提供多播/广播通信的基本无线电接入网络 (RAN) 功能。这项工作最初排除了最初支持 LTE 下地面广播服务的一些功能，例如免费广播、仅接收模式、大面积单频网络等。本文提出了一种基于 3GPP 第 15 版的增强型下一代 RAN 架构，具有一系列架构和功能增强功能，以支持在单播和多播/广播传输模式之间进行高效、灵活和动态的选择，以及地面广播服务的交付。本文详细阐述了基于 Cloud-RAN 的架构，并提出了新概念，例如 RAN 广播/多播区域，与 eMBMS 相比，它允许更灵活的部署。包括复杂性分析和检查在内的高级评估方法用于评估所提议架构设计的可行性，并将其与 3GPP 架构要求进行比较。单播和多播/广播传输模式之间灵活和动态的选择，以及地面广播服务的交付。本文详细阐述了基于 Cloud-RAN 的架构，并提出了新概念，例如 RAN 广播/多播区域，与 eMBMS 相比，它允许更灵活的部署。包括复杂性分析和检查在内的高级评估方法用于评估所提议架构设计的可行性，并将其与 3GPP 架构要求进行比较。单播和多播/广播传输模式之间灵活和动态的选择，以及地面广播服务的交付。本文详细阐述了基于 Cloud-RAN 的架构，并提出了新概念，例如 RAN 广播/多播区域，与 eMBMS 相比，它允许更灵活的部署。包括复杂性分析和检查在内的高级评估方法用于评估所提议架构设计的可行性，并将其与 3GPP 架构要求进行比较。