Open, Programmable, and Virtualized 5G Networks: State-of-the-Art and the Road Ahead

Abstract

Fifth generation (5G) cellular networks will serve a wide variety of heterogeneous use cases, including mobile broadband users, ultra-low latency services, and massively dense connectivity scenarios. The resulting diverse communication requirements will demand networking with unprecedented flexibility, not currently provided by the monolithic and black-box approach of 4G cellular networks. The research community and an increasing number of standardization bodies and industry coalitions have recognized softwarization, virtualization, and disaggregation of networking functionalities as the key enablers of the needed shift to flexibility. Particularly, software-defined cellular networks are heralded as the prime technology to satisfy the new application-driven traffic requirements and to support the highly time-varying topology and interference dynamics, because of their openness through well-defined interfaces, and programmability, for swift and responsive network optimization. Leading the technological innovation in this direction, several 5G software-based projects and alliances have embraced the open source approach, making new libraries and frameworks available to the wireless community. This race to open source softwarization, however, has led to a deluge of solutions whose interoperability and interactions are often unclear. This article provides the first cohesive and exhaustive compendium of recent open source software and frameworks for 5G cellular networks, with a full stack and end-to-end perspective. We detail their capabilities and functionalities focusing on how their constituting elements fit the 5G ecosystem, and unravel the interactions among the surveyed solutions. Finally, we review hardware and testbeds on which these frameworks can run, and provide a critical perspective on the limitations of the state-of-the-art, as well as feasible directions towards fully open source, programmable 5G networks.

4C: A Computation, Communication, and Control Co-Design Framework for CAVs

“…Traditionally, cellular communications like 4G, LTE, and vehicle communications like DSRC are deployed in a "black-box" fashion, where the communication hardware and software are plug-and-play. This approach's limitation is that the devices and software cannot configure, contributing to low flexibility and programmability [12]. Recently, many efforts have been made in pushing the softwarization and virtualization of network resources, including software-defined radio (SDR), network function virtualization (NFV), network slicing, etc.…”

“…The communication module in the 4𝐶 framework is built on SDR devices that have reconfiguration capability. On top of that, open-source software includes OpenAirInterface (OAI), and srsLTE are implemented to provide full-stack cellular network functions [12]. Both OAI and srsLTE include the software stack for the core network (EPC), the base station (eNodeB), and user equipment (UE).…”

OPlaceRAN -- a Placement Orchestrator for Virtualized Next-Generation of Radio Access Network

“…Moreover, recent results show that the containerized solution tends to be the most appropriate for RAN virtualization due to the strict requirements of delay and scalability of resources. In this sense, each virtualized radio function is envisioned as a container [27], [29]- [31]. For the orchestration of containers in generic applications, four tools lead the implementations: (i) K8S, (ii) Docker Swarm, (iii) Mesosphere Marathon, and (iv) Cloudify.…”

Small-Scale 5G Testbeds for Network Slicing Deployment: A Systematic Review

“…We describe most of the state-of-the-art testbeds designed for implementing network slicing. We exclude large scale testbeds that are costly in terms of equipment and human resources as some of them are already explained in [16], [17].…”

“…Reference [15] investigates the necessity of network slicing for facilitating the implementation of Internet-of-Things (IoT) intelligent applications and smart services. Bonati et al in [16] describe open source utilities, frameworks, and hardware components that can be used to instantiate softwarized 5G networks. Barakabitze et al [17] provide a comprehensive review of 5G networks, a tutorial of the 5G network slicing technology enablers including SDN, NFV, MEC, Cloud/Fog computing, network hypervisors, virtual machines, and containers, as well as an overview of collaborative large 5G network slicing implementations.…”