Description
Service Exposure and Enablement Support (SEES) is a standardized architectural framework within 3GPP that defines the mechanisms for securely and efficiently exposing network capabilities and information to trusted third-party application providers. It operates as a layer of abstraction between the core network functions and external applications, providing a set of Application Programming Interfaces (APIs) that abstract the underlying network complexity. These APIs allow external entities to request network services, access subscriber data (with consent), and trigger network events without needing deep knowledge of the proprietary network protocols. The framework is crucial for enabling new vertical services and partnerships, such as those in IoT, enterprise communications, and edge computing.
The architecture of SEES typically involves key functional entities like the Network Exposure Function (NEF) in the 5G Core, which acts as the primary point for API exposure. SEES builds upon this by providing the policy, security, and lifecycle management for these exposures. It defines standardized northbound APIs (e.g., based on RESTful principles) that third-party Application Functions (AFs) can consume. The framework ensures that all exposure is governed by policies that enforce security, privacy, and network resource protection. It handles authentication and authorization of the third parties, manages API versioning and deprecation, and provides charging and billing interfaces for monetizing the exposed capabilities.
SEES works by translating high-level service requests from external applications into specific network commands or information retrievals from the relevant Core Network functions. For instance, an application might request quality of service (QoS) enhancement for a specific user session, and SEES would translate this into the appropriate policy control interactions with the Policy Control Function (PCF) and Session Management Function (SMF). It also supports event exposure, where the network can notify subscribed applications about specific occurrences, such as a user's location change or connectivity status update. This event-driven model is essential for real-time applications. The framework's role is to make the network programmable and open, transforming it from a closed infrastructure into a platform for service innovation while maintaining strict operational control and security.
Purpose & Motivation
SEES was created to address the growing demand from enterprises and application developers for direct, programmable access to telecom network capabilities. Historically, network functions were siloed and accessed through proprietary interfaces, making it difficult and costly for third parties to integrate and create new services. The rise of cloud-native applications and the need for network-aware services (like augmented reality, connected vehicles, and smart factories) necessitated a standardized, secure method for exposure. SEES solves the problem of network 'walled gardens' by providing a controlled gateway.
The primary motivation was to unlock new revenue streams for mobile operators by enabling them to monetize their network assets beyond basic connectivity. By exposing capabilities like QoS control, location information, network status, and device triggering, operators can offer value-added services to vertical industries. SEES also addresses the technical challenge of scaling exposure securely; without a framework like SEES, each new API or partner would require custom integration, increasing complexity and security risks. It standardizes the exposure layer, reducing integration time and cost while ensuring consistent security and policy enforcement across all third-party interactions.
Classification
Detected Changes Across Releases
from 3GPP Change RequestsSpecific changes extracted from the „Change history“ tables of 3GPP specifications (17 CRs across 5 releases). Complements the general historical overview above with the evidence-based evolution of this function.
Studied in Rel-14, normative work from Rel-16.
In Release 16, the SEES function was enhanced to support new security requirements based on the FS_CAV study and received an update for 5G LAN-type service exposure. These updates ensure the 5G system can securely expose its capabilities, such as those for flexible enterprise networks and 5G LAN-virtual networks, to authorized external applications. This enables advanced business models and supports stringent performance indicators for diverse services like factory automation.
In Release 17, the SEES function was enhanced to support new deployment scenarios and business models, specifically by enabling service exposure for Mission Critical Services over broadcast/multicast in 5G. Furthermore, it introduced support for exposing IMS emergency service capabilities within Non-Public Networks (NPNs), aligning with the requirement for flexible network operations in diverse enterprise and specialized environments.
In Release 18, the SEES function was enhanced to support service function chaining within the 5G network and to improve service exposure for Non-Public Networks (NPNs). Specifically, new requirements were introduced to enable a UE to access multiple non-public networks and corresponding simultaneous services. Furthermore, support for NPNs was extended to include positioning service requirements.
- Service requirements for enhancing service function chaining support by 5G network TS 22.261CR0478
- Update to KPIs to 5G system with satellite access for support control and/or video surveillance TS 22.261CR0519
- Support multiple non-public networks access and corresponding simultaneous services for a UE TS 22.261CR0564
- Editorial correction for network capability exposure and abbreviation TS 22.261CR0524
- NPN support for positioning service requirement TS 22.261CR0626
In Release 19, the SEES function introduced new requirements for supporting UE mobility for XR services and for enabling local traffic routing for UEs with multiple access technologies to the 5G system. It also added specific support for roaming service providers within the 5G architecture, enhancing the ability of a Visited Mobile Network to provide services. These enhancements build upon the 5G system's foundational capabilities in network slicing, diverse mobility, and support for multiple access technologies.
- Supporting UE Mobility for XR service TS 22.261CR0677
- Add requirements on supporting local traffic routing for UEs with multiple accesses to 5G TS 22.261CR0709
- Supporting UE Mobility for XR service TS 22.261CR0719
- Support for Multiple Spanning Tree Protocol TS 22.261CR0781
- Roaming service providers enablement in 5G TS 22.261CR728
In Release 20, the SEES function introduced new requirements to support diverse device types, specifically for legacy residential gateways (eRGs) providing 5G LAN-type services. This enhancement expanded the deployment scenarios for enterprise and managed networks by ensuring these legacy devices could integrate into the 5G system's flexible and customizable architecture. The focus was on enabling these varied UEs to access network slices and services, aligning with the system's objective to support new business models and self-contained enterprise networks.
Explore further
Broader topics and technologies where SEES plays a role.
Defining Specifications
3GPP specifications that define or reference SEES, with the latest known release. Sourced from the 3GPP document catalog — see methodology.
| Specification | Title | Release |
|---|---|---|
| TS 22.261 vk30 | 5G System Service Requirements | Rel-20 |
| TS 22.864 vf00 | 5G Network Operation Use Cases & Requirements | Rel-15 |