# On the Rollout of Network Slicing in Carrier Networks: A Technology Radar
## 4 Network Slicing Technology Radar  
Network slicing is an E2E solution, covering the three technology domains: RAN, CN and TN. The provisioning and operation of the different slices, and the lifecycle management of hosted services, is done with a cloud-native OSS stack composed of a number of management domains, including vertical domains (e.g., RAN, CN, TN management domains) and horizontal domains (e.g., MANO and E2E management domains). The maturity level of slicing varies across all these technology and management domains. This fact, together with the integration complexity of carrier networks (e.g., brownfield facilities, multi-vendor solutions), defines challenges that operators need to work out to enable the full promise of network slicing in a later phase. Although standards and technologies do not currently support full slicing capabilities, it is important to get started with early-stage slicing and to use a vision of what is desired in the longer term to guide progress and focus. For operators, it is important to take a phased-based approach, establishing a process to incorporate learnings at each stage of the slicing journey. Figure 8: Soft, hard and hybrid slicing in transport networks. The mission of this section (and upcoming ones) is to present a network slicing technology radar that can help operators to build their own journey towards the commercialization and monetization of slicing. As shown in Figure 9, this radar captures a list of solutions for network slicing impacting all relevant operator's sub-systems, including RAN, TN, CN and OSS. This is complemented by an assessment work, called ring assignment. In particular, we use four rings with the following semantics:  
* **As-is ring**: represents solutions that are available in today's carrier networks. These solutions are typically associated with technologies that operators have high confidence in, with low risk and recommended to be available across the entire service footprint. In terms of 5G roll-out strategy, this corresponds to 5G NSA (Non Standalone) [37]. * **Deploy ring**: covers the slicing solutions that can be applied in early 5G SA (Standalone) networks, based on 3 GPP Release 15 standards. Some operators have already started to activate their SA networks, while some others expect to get them operationally ready within next year. With this timing in mind, we can say that this ring captures proven slicing solutions that operators may integrate in the short-term. * **Test ring**: captures slicing solutions that are much more focused on satisfying requirements from uRLLC and mIoT services. Associated with brand new Rel-16 features, these solutions have great potential but are unproven in production networks, hence it is worth operators investing in prototyping efforts in order to evaluate their performance and impact. This evaluation is typically done with commercial trials, either bilateral or multi-vendor, and different Proof of Concepts (PoCs). The upgrade towards Rel-16 is expected within the next 2-3 years; this means that test ring represents slicing solutions that might be available in the medium term. * **Explore ring**: includes slicing solutions that are foreseen in the long run, starting in the next 4-5 years. These solutions, tied to features from 3 GPP Rel-17 on wards, promise to provide great potential, though their impact and commercial availability is still far from crystal clear. The role of the operator is to keep track of their evolution through exploratory activities such as the ones done in research and innovation projects, e.g., 5G-VINNI [38], 5 GROWTH [39] and 5G-CLARITY [40]. Figure 9: Network slicing technology radar.