Network Slice Capability Enablement

Description

Network Slice Capability Enablement (NSCE) is a comprehensive framework introduced in 3GPP Release 17 to facilitate the interaction between applications (or vertical industry systems) and the underlying 5G network slicing capabilities. It operates as an intermediary layer, translating high-level application requirements into specific network slice selection and configuration parameters that the 5G core network can understand and provision. The architecture involves several key functional components, primarily the NSCE Capability Exposure Function (NSCE-CEF) and the NSCE Application Function (NSCE-AF). The NSCE-CEF is responsible for exposing the network's slice capabilities, such as available slice types, performance characteristics (latency, bandwidth), and service area coverage, to authorized external entities. The NSCE-AF, residing in the application domain, formulates service requests based on application needs and communicates with the NSCE-CEF via standardized APIs, such as those defined in TS 29.549.

The workflow begins with capability discovery, where an application queries the NSCE-CEF to understand what slice capabilities are available in a given geographical area. Based on this information, the application can then request the enablement of a specific network slice instance or the utilization of an existing one that matches its requirements. The NSCE framework handles the mapping of application-level parameters (e.g., 'ultra-reliable low-latency communication for factory automation') to technical network slice selection assistance information (NSSAI) and potentially interacts with the Network Slice Selection Function (NSSF) and Policy Control Function (PCF) within the 5G core to ensure the appropriate slice is selected and policies are applied for the user equipment (UE). This process includes lifecycle management aspects, allowing for modification or termination of slice usage as application sessions evolve.

NSCE's role is pivotal in realizing the full economic potential of 5G network slicing for vertical industries. It moves beyond simple slice provisioning by the operator, enabling a dynamic, demand-driven model where applications can actively participate in the slice selection and configuration process. This requires robust authentication, authorization, and accounting (AAA) mechanisms, as defined in the relevant security specifications, to ensure that only authorized applications can access and control network resources. By providing a standardized interface for slice capability exposure, NSCE reduces integration complexity for application developers and enables new business models, such as slice-as-a-service, where verticals can on-demand access tailored network performance guarantees.

Purpose & Motivation

NSCE was created to address a critical gap in the initial 5G network slicing architecture defined in Releases 15 and 16. While those releases standardized the core mechanisms for creating and managing network slices within the operator's domain, they provided limited, non-standardized means for external applications and vertical industry customers to interact with these slices. The lack of a standardized exposure interface meant each operator had to develop custom APIs, leading to fragmentation, high integration costs for application providers, and an inability to create portable applications across different operator networks. This hindered the commercialization of network slicing, particularly for enterprise and IoT use cases which require programmatic access to network resources.

The primary problem NSCE solves is the disconnection between the technical implementation of network slices and the business or service logic of applications. Before NSCE, an enterprise might have to engage in lengthy manual processes with an operator to procure a slice with specific characteristics. NSCE automates and standardizes this interaction, enabling applications to dynamically discover and request network capabilities that match their real-time needs. This is essential for use cases like automated guided vehicles (AGVs) in a smart factory, where the application software needs to guarantee a certain level of network performance before initiating a critical operation. The motivation was to unlock the revenue potential of 5G for operators by making slicing easily consumable, fostering an ecosystem of slice-aware applications, and accelerating the adoption of 5G in vertical markets such as manufacturing, healthcare, and transportation.

Key Features

• Standardized capability exposure APIs (e.g., Nnscf_NSCE_CapabilityExposure) for discovering available network slice types and their attributes.
• Dynamic slice enablement request interface allowing applications to request activation or usage of a specific network slice instance.
• Mapping of application-level service requirements to 3GPP-defined network slice selection parameters (S-NSSAI, DNN).
• Integration with core network functions (NSSF, PCF) for slice selection and policy enforcement based on application requests.
• Support for slice capability exposure per geographical area, enabling location-aware service delivery.
• Lifecycle management for the association between an application session and a network slice, including modification and termination.

Evolution Across Releases

Defining Specifications