The upcoming Sixth Generation (6G) mobile communications system envisions supporting a variety of use cases with differing characteristics, e.g., very low to extremely high data rates, diverse latency needs, ultra massive connectivity, sustainable communications, ultra-wide coverage etc. To accommodate these diverse use cases, the 6G system architecture needs to be scalable, modular, and flexible; both in its user plane and the control plane. In this paper, we identify some limitations of the existing Fifth Generation System (5GS) architecture, especially that of its control plane. Further, we propose a novel architecture for the 6G System (6GS) employing Software Defined Networking (SDN) technology to address these limitations of the control plane. The control plane in existing 5GS supports two different categories of functionalities handling end user signalling (e.g., user registration, authentication) and control of user plane functions. We propose to move the end-user signalling functionality out of the mobile network control plane and treat it as user service, i.e., as payload or data. This proposal results in an evolved service-driven architecture for mobile networks bringing increased simplicity, modularity, scalability, flexibility and security to its control plane. The proposed architecture can also support service specific signalling support, if needed, making it better suited for diverse 6GS use cases. To demonstrate the advantages of the proposed architecture, we also compare its performance with the 5GS using a process algebra-based simulation tool.

翻译：即将到来的第六代（6G）移动通信系统旨在支持具有不同特性的各类用例，例如从极低到极高的数据速率、多样化的时延需求、超大规模连接、可持续通信、超广覆盖等。为适应这些多样化用例，6G系统架构需要在用户面和控制面均具备可扩展性、模块化和灵活性。本文识别了现有第五代系统（5GS）架构的一些局限性，特别是其控制面的不足。进一步，我们提出了一种采用软件定义网络（SDN）技术的6G系统（6GS）新架构，以解决控制面的这些局限性。现有5GS的控制面支持两类不同功能：处理终端用户信令（如用户注册、认证）和控制用户面功能。我们建议将终端用户信令功能移出移动网络控制面，并将其视为用户服务，即作为有效载荷或数据。这一提议产生了一种演进的服务驱动型移动网络架构，为其控制面带来了更高的简洁性、模块化、可扩展性、灵活性和安全性。所提架构在需要时还可支持特定服务的信令支持，从而更好地适配多样化的6GS用例。为展示所提架构的优势，我们还使用基于进程代数的仿真工具将其性能与5GS进行了比较。