# On the Rollout of Network Slicing in Carrier Networks: A Technology Radar
## 1 Introduction
The purpose of this paper is to address the first step, outlining a technology radar to model this common space. This radar presents a phased-based vision for the introduction of network slicing capabilities in commercial networks, considering all the domains impacted in operator assets, including the main three technology domains and the OSS. In this vision, the radar identifies different solutions for network slicing and captures them into four rings, each corresponding to a different timeline: as-is ring (today's slicing), deploy ring (short-term slicing), test ring (medium-term slicing) and explore ring (long-term slicing). The position of each solution in the radar is done according to three different criteria: (i) the technology maturity of the solution, which is related to the readiness of the corresponding standards; (ii) the roadmap of commercial products, which specifies when the features associated with the solution will be available; and (iii) the relevance for the customers, which determines the prioritization of the solution over others. To the best of our knowledge, this is the first work in the literature that provides a radar for E2E network slicing, with a focus on the rollout of this technology in carrier networks. The radar captures a complete landscape of network slicing solutions, linking them to different timelines. In addition to this timing, the radar will also outline the dimensions impacting slice realization, from E2E viewpoint. These dimensions are to be analyzed in each of the operator managed domains, including Radio Access Network (RAN), Core Network (CN), Transport Network (TN) and OSS. In the _RAN domain_, network solutions are to be discussed based on three dimensions: functionality (e.g., disaggregation and O-RAN integration), radio resource allocation and penetration (in micro and macro cells). The _CN domain_ will focus on how to use and combine core network functions for different slices, including baseline and value-added functions, depending on isolation and customer requirements. In the _TN domain_, slicing is to be discussed based on the availability of transport technologies and SDN-enabled capabilities, including programmability and automation. Finally, in the _OSS domain_, aspects related to network slice lifecycle management and capability exposure (i.e., to expose slicing capabilities to customers through service APIs) will be taken into account. These dimensions are used to characterize the different solutions captured in the radar, providing guidance on how and where using them. This information, together with the timeline provided for these solutions, is the input material that enables an operator to define the plan for network slicing rollout. For further details on how to design and execute this plan, see recommendations reported in [4; 5; 6]. This article is structured as follows. Section 2 provides the technical background of E2E network slicing, with focus on the modelling, system architecture and deployment related aspects. Section 3 outlines the impact that the network slicing may introduce on the different technology domains. The understanding of these features will enable the reader to understand the radar, which is introduced in Section 4. The radar is the core contribution of this article, and hence deserves a detailed discussion, with a thorough analysis of all the solutions along the different dimensions: CN (Section 5), RAN (Section 6), TN (Section 7) and OSS (Section 8). Finally, Section 9 summarizes the main conclusions of this work.