Recent advancements in wireless technologies towards the next-generation cellular networks have brought a new era that made it possible to apply cellular technology on traditionally-wired networks with tighter requirements, such as industrial networks. The next-generation cellular technologies (e.g., 5G and Beyond) introduce the concept of ultra-reliable low-latency communications (URLLC). This thesis presents a Software-Defined Networking (SDN) architecture with programmable data planes for the next-generation cellular networks to achieve URLLC. Our design deploys programmable switches between the cellular core and Radio Access Networks (RAN) to monitor and modify data traffic at the line speed. We introduce the concept of \textit{intra-cellular optimization}, a relaxation in cellular networks to allow pre-authorized in-network devices to communicate without being required to signal the core network. We also present a control structure, Unified Control Plane (UCP), containing a novel Ethernet Layer control protocol and an adapted version of link-state routing information distribution among the programmable switches. Our implementation uses P4 with an 5G implementation (Open5Gs) and a UE/RAN simulator. We implement a Python simulator to evaluate the performance of our system on multi-switch topologies by simulating the switch behavior. Our evaluation indicates latency reduction up to 2x with \textit{intra-cellular optimization} compared to the conventional architecture. We show that our design has a ten-millisecond level of control latency, and achieves fine-grained network security and monitoring.

翻译：近年来，面向下一代蜂窝网络的无线技术发展迈入了新纪元，使得蜂窝技术能够应用于传统有线网络中要求更为严苛的场景（如工业网络）。下一代蜂窝技术（如5G及未来演进）引入了超可靠低延迟通信（URLLC）的概念。本文提出了一种基于可编程数据平面的软件定义网络（SDN）架构，旨在为下一代蜂窝网络实现URLLC。该设计在蜂窝核心网与无线接入网（RAN）之间部署可编程交换机，以实现对数据流量的线速监控与修改。我们引入了"蜂窝内部优化"概念，即放宽蜂窝网络中的要求，允许预授权的网内设备无需向核心网发送信令即可直接通信。此外，我们提出了一种统一控制平面（UCP）控制结构，包含一种新型以太网层控制协议以及链路状态路由信息在可编程交换机间的自适应分发机制。实现方案采用P4语言结合5G实现框架（Open5Gs）及用户设备/无线接入网（UE/RAN）模拟器。我们开发了Python模拟器，通过模拟交换机行为评估系统在多交换机拓扑下的性能。评估结果表明，与传统架构相比，采用蜂窝内部优化后延迟可降低至原来的二分之一。我们展示了设计具有十毫秒级的控制延迟，并能实现细粒度的网络安全与监控。