Description
The Source Edge Enabler Server (S-EES) is a core component of the 3GPP Edge Computing Enabler Layer (ECEL) architecture defined from Release 17. It functions as a service discovery and access gateway for application clients (ACs) seeking to utilize edge computing resources. The S-EES is typically deployed within the operator's network or a trusted third-party domain. Its primary role is to act as a trusted intermediary that an AC first contacts. The AC provides the S-EES with a service description or identifier for the edge application it wishes to consume. The S-EES then consults with other ECEL entities, primarily the Edge Configuration Server (ECS), to discover the appropriate Edge Application Server (EAS) instances that can fulfill the request. This discovery process considers factors like the client's location, network conditions, and EAS capabilities to select an optimal endpoint. Once a suitable EAS is identified, the S-EES provides the AC with the necessary information, such as an IP address or FQDN, and often a secure access token, to establish a direct or proxied connection to the EAS. This architecture abstracts the complexity of the edge deployment from the application, enabling dynamic service discovery and seamless mobility as clients move between different edge service areas. The S-EES also plays a crucial role in security, enforcing authentication and authorization policies for ACs before revealing EAS details, thereby protecting the edge infrastructure from unauthorized access. It interfaces with the ECS using the En-1 reference point and with ACs via the En-2 reference point, as specified in TS 23.558.
Purpose & Motivation
The S-EES was created to address the challenges of service discovery and access in distributed edge computing environments. Prior to its standardization, accessing edge applications often required static configuration or proprietary discovery mechanisms, which were not scalable, secure, or interoperable across different operators and vendors. The proliferation of latency-sensitive and bandwidth-intensive applications, such as augmented reality, industrial automation, and video analytics, necessitated a standardized way to dynamically find and connect to the closest or most suitable compute instance. The S-EES solves this by providing a centralized, trusted point of contact for clients. It decouples the client application from the physical and logical topology of the edge network, enabling operators to deploy, manage, and scale their edge resources independently. This standardization, initiated in Release 17, was motivated by the need to foster an ecosystem of interoperable edge services, reduce integration complexity for application providers, and ensure secure and efficient utilization of edge computing infrastructure as a key enabler for 5G and beyond networks.
Detected Changes Across Releases
from 3GPP Change RequestsSpecific changes extracted from the „Change history“ tables of 3GPP specifications (14 CRs across 2 releases). Complements the general historical overview above with the evidence-based evolution of this function.
Studied in Rel-17, normative work from Rel-18.
In Release 18, the S-EES (Source Edge Enabler Server) function was enhanced to support Application Context Transfer (ACT) procedures involving a Cloud Application Server (CAS). Specifically, new scenarios were defined for CAS-decided and S-EES-executed ACT, including support for bundling multiple Edge Application Servers (EAS) within the same DNAI and handling architectures without a Cloud Enabler Server (CES).
- ACR with CAS - EEC executed ACR via S-EES TS 23.558CR0334
- ACR with CAS - S-EES executed ACR TS 23.558CR0338
- Bundle EAS ACR within the same DNAI for S-EES executed ACR TS 23.558CR0376
- CAS decided ACR scenario via old S-EES for CESless architecture TS 23.558CR0401
- Profile information sources TS 23.558CR0331
- Cleanup on CAS decided ACR scenario via the last S-EES TS 23.558CR0464
+ 2 more changes
In Release 19, the S-EES (Source Edge Enabler Server) function was enhanced to instigate Application Context Transfer (ACR) and manage service continuity for common EASs during overload situations. Specific corrections were made to procedures for S-EES executed ACR when interacting with a Cloud Application Server (CAS) and for scenarios involving satellite access. These updates refined the edge enabler layer's role in maintaining service continuity and managing application context between servers.
- Instigating ACR at the edge enabler server (EES) TS 23.558CR0561
- Service continuity for common EAS (overload situation) – S-EES detected scenario. TS 23.558CR0608
- Solve EN in S-EES executed ACR TS 23.558CR0681
- Correction on Edge Enabler Using Satellite Access TS 23.558CR0738
- Correction on Edge Enabler Using Satellite Access TS 23.558CR0742
- Correction in S-EES executed ACR to CAS TS 23.558CR0554
Explore further
Broader topics and technologies where S-EES plays a role.
Defining Specifications
3GPP specifications that define or reference S-EES, with the latest known release. Sourced from the 3GPP document catalog — see methodology.
| Specification | Title | Release |
|---|---|---|
| TS 23.558 vk00 | Architecture for Edge Applications | Rel-20 |
| TS 29.558 vj40 | Enabling Edge Applications | Rel-19 |
| TR 33.739 vi10 | Study on security enhancement of support for | Rel-18 |