How does the 5G Core network handle network slicing orchestration and management?

Network slicing is a key feature of 5G networks that allows the creation of multiple virtual networks on a shared physical infrastructure. Each network slice is customized to meet specific requirements, such as latency, bandwidth, and reliability, making it suitable for diverse use cases. The 5G Core (5GC) network is responsible for orchestrating and managing these network slices. Let's delve into the technical details of how this is achieved:

1. Network Slice Selection Function (NSSF):
   • The NSSF is a critical component in the 5G Core that plays a central role in network slice selection. It determines the appropriate network slice instance for a specific service or application based on the requirements provided during the service request.
2. Policy Control Function (PCF):
   • The PCF is responsible for managing policies related to quality of service (QoS), access control, and flow control. It interacts with other network functions to enforce policies associated with each network slice. The PCF ensures that the network resources are allocated according to the slice's characteristics.
3. Session Management Function (SMF):
   • The SMF handles session management and mobility aspects for user equipment (UE). It is aware of the specific network slice instance associated with a UE and ensures that the UE's communication adheres to the slice's requirements. The SMF coordinates with other network functions to establish, modify, or release sessions within a network slice.
4. User Plane Function (UPF):
   • The UPF is responsible for handling the user plane traffic in the 5G network. It plays a crucial role in data forwarding and packet processing. For network slicing, there can be multiple UPF instances, each associated with a different slice, to ensure that the user plane traffic is appropriately handled according to the slice's requirements.
5. Network Slice Subnet (NSS):
   • The NSS is a collection of network functions that together define a specific network slice. It includes the SMF, UPF, and other functions necessary to meet the requirements of the slice. The NSS is orchestrated and managed by the 5G Core to ensure the proper instantiation and operation of each network slice.
6. Network Slice Repository (NSR):
   • The NSR is a centralized repository that stores information about available network slices, their characteristics, and their resource requirements. The 5G Core consults the NSR during network slice selection to determine the most suitable slice for a given service or application.
7. Network Slice Management and Orchestration (NSMO):
   • NSMO is responsible for the end-to-end orchestration and lifecycle management of network slices. It interfaces with the NSSF, PCF, SMF, UPF, NSR, and other network functions to ensure the dynamic creation, modification, and termination of network slices as per the changing requirements of services and applications.
8. Service Level Agreement (SLA) Monitoring:
   • The 5G Core continuously monitors the performance of each network slice based on the defined SLAs. If the actual performance deviates from the agreed-upon parameters, the 5G Core takes corrective actions, such as reallocating resources or modifying the slice configuration, to maintain the desired service quality.