TU-T [179] for network slicing is presented in Fig. 1.10. It considers three layers, i.e., service instance, network slice instance (NSI), and resource layers. The service instance layer represents the application or the end-user services provided by tenants or network services providers [165]. Meanwhile, the NSI provides the dedicated features for the service instance, and it could be fully static, partially dynamic, or constructed on-demand [180]. One or several instance services can be served by one or several NSI. An instance service can be identified and chained to a corresponding NSI by a network slice blueprint. The network slice blueprint provides a full description of the configuration and specifications of the instance service as well as it is used by the MNO to instantiate and manage the NSI. 1.4.4 Artificial Intelligence/Machine Learning (AI/ML) AI/ML is vital for 5G networks and beyond because it provides efficient tools for network planning, diagnostics, and optimization [181]. The heterogeneity of 5G networks with the diverse and high number of services poses challenges on the Table 1.7 Research works on network slicing architecture Document type Title Description References Standard 3GPP TS38.300: NR and NG-RAN overall Describe the general principles, requirements, [164] and [169] description-stage 2 3GPP TS23.501: System functions, and configurations for network slicing architecture for the 5G system-Stage 2 architecture in NG-RAN and CN ITU-T Y.3112 series Y: Global information Present a high level of requirements and CN [170] infrastructure, Internet protocol aspects, functions for network slicing next-generation networks, IoT, and smart cities Articles Adaptive Network Slicing in Multi-Tenant 5G IoT Describe the control and management network slicing [171] Networks architectural frameworks for 5G IoT Network slicing in 5G mobile communication: Describe the network slicing architecture considering [172] Architecture, prototype modelling, and challenges RAN, CN, and pairing functions slices An E