Description
Service Enabler Architecture Layer – Data Delivery (SEALDD) is a specialized function introduced as part of the broader SEAL framework in 3GPP Release 18. Its primary role is to manage and optimize the delivery of data between vertical applications and groups of User Equipments (UEs) or between UEs themselves. SEALDD acts as an intelligent data plane agent that understands application context and network conditions. Key architectural components include data routing logic, caching capabilities, transcoding/adaptation functions, and interfaces for group management. It works by receiving data delivery requests from a vertical application via the SEAL northbound API. These requests specify parameters such as target group (defined via the SEAL Group Management enabler), data priority, required latency, and geographic area. SEALDD then determines the most efficient delivery strategy, which may involve unicast, multicast, or broadcast mechanisms, potentially leveraging 5G Multicast-Broadcast Services (MBS). It can cache popular content at the network edge to reduce latency and core network load. For example, in a V2X scenario, SEALDD can efficiently distribute high-definition map updates to all vehicles in a specific city district. It interfaces with other SEAL enablers (for group and location info) and core network functions like the Network Exposure Function (NEF) and User Plane Function (UPF) to execute the delivery. Its operation includes applying relevant policies for quality of service, security, and charging. By abstracting these complex data delivery mechanisms, SEALDD allows vertical applications to request sophisticated data distribution without managing underlying network transport details.
Purpose & Motivation
SEALDD was created to address specific data delivery challenges faced by vertical applications in 5G and beyond. Prior to its introduction, while SEAL provided management enablers, efficient, scalable, and context-aware data distribution was not fully standardized. Verticals like connected cars (V2X), drone swarms, and large-scale IoT deployments require efficient group communication, low-latency data pushes, and adaptive content delivery based on location or network conditions. Implementing these features ad-hoc was complex and inefficient. The purpose of SEALDD is to fill this gap by providing a standardized, network-integrated data delivery service within the SEAL ecosystem. It solves problems like network congestion from redundant unicast streams, high latency for edge services, and the complexity of using multicast/broadcast services directly. By offering application-aware data delivery as a service, SEALDD enables verticals to build scalable data-intensive applications, optimizes network resource utilization, and is a key enabler for 5G Advanced use cases like extended reality (XR) and collaborative robots, where efficient data dissemination is critical.
Classification
Release Timeline
Detected Changes Across Releases
from 3GPP Change RequestsSpecific changes extracted from the „Change history“ tables of 3GPP specifications (143 CRs across 3 releases). Complements the general historical overview above with the evidence-based evolution of this function.
In Release 18, the SEALDD (Service Enabler Architecture Layer – Data Delivery) function was formally introduced, establishing core mechanisms for application signalling and media data transmission between VAL clients and servers. The release specified new procedures including SEALDD server discovery, context transfer with policy information, client-initiated connection release, and a defined overall lifecycle. It also introduced capabilities for End-to-End (E2E) redundant transmission with packet duplication, crossflow QoS measurement for multi-modal flows, and data transmission rate control, while providing various corrections to foundational APIs and connection management procedures.
- Introducing SEALDD support TS 24.257CR0030
- Introducing SEALDD support TS 24.486CR0175
- Introducing SEALDD support TS 24.538CR0113
- Definition of SEALDD related functionalities TS 29.549CR0145
- Introducing cause field and transfer of SEALDD server policy information in context transfer procedure TS 23.433CR0001
- SEALDD client initiated connection release TS 23.433CR0002
+ 13 more changes
In Release 19, the SEALDD function introduced significant enhancements for multi-modal services like XR, including explicit support for multi-modal SEALDD flows and crossflow QoS measurement for synchronized traffic. It expanded policy and quality control with new capabilities for geofencing, background data transfer, and client-initiated connection establishment. Furthermore, the release strengthened support for URLLC through enhanced redundant transmission procedures and added new service operations for updating and deleting client policy configurations.
- SEALDD transmission quality guarantee with BAT and periodicity adaptation TS 23.433CR0015
- Correction on SEALDD enabled congestion control for VAL application by supporting L4S mechanism TS 23.433CR0021
- Provisioning a Geofence policy in the SEALDD server TS 23.433CR0023
- Enhancements to the SEALDD connection status procedure TS 23.433CR0024
- Seamless SEALDD relocation enhancement TS 23.433CR0032
- SEALDD Background data transfer TS 23.433CR0051
+ 106 more changes
In Release 20, the SEALDD function introduced several new capabilities including explicit support for QoS differentiation for non-3GPP devices and the formal definition of the SEALDD-UU and SEALDD-S protocol stacks. It also added new service features such as SEALDD-enabled multicast/broadcast delivery, enhanced policy enforcement, and more detailed procedures for regular connection establishment with SLA indications. Furthermore, the release provided clarifications on the functional model and interfaces while adding support for multi-modal transmission flows and congestion control enhancements for VAL applications.
- Support of QoS differentiation for non-3GPP devices in SEALDD layer TS 23.433CR0184
- Addition of the protocol stacks for SEALDD-UU and SEALDD-S TS 23.433CR0189
- Addition of the user plane protocol stack examples for SEALDD-UU and SEALDD-S TS 23.433CR0190
- Support on SEALDD enabled Multicast and Broadcast data delivery service TS 23.433CR0193
- Support on the SEALDD policy enforcement. TS 23.433CR0194
- Support on the SEALDD regular connection establishment with additional indication of SLA on QoS service type TS 23.433CR0195
+ 6 more changes
Explore further
Broader topics and technologies where SEALDD plays a role.
Defining Specifications
3GPP specifications that define or reference SEALDD, with the latest known release. Sourced from the 3GPP document catalog — see methodology.
| Specification | Title | Release |
|---|---|---|
| TS 23.433 vk00 | SEAL Data Delivery (SEALDD) for Verticals | Rel-20 |
| TS 23.482 vk00 | AIML Enablement Service Architecture | Rel-20 |
| TS 23.700 vk00 | XR Services Application Enablement Layer | Rel-20 |
| TS 24.257 vj40 | UAS Application Enabler (UAE) Layer | Rel-19 |
| TS 24.486 vj00 | V2X Application Enabler (VAE) Protocol Spec | Rel-19 |
| TS 24.538 vj30 | MSGin5G Service Protocol Specification | Rel-19 |
| TS 24.543 vj50 | SEAL Data Delivery Management Protocol | Rel-19 |
| TS 29.548 vj40 | SEAL Data Delivery Server Services Stage 3 | Rel-19 |
| TS 29.549 vj40 | SEAL API Specification for Vertical Applications | Rel-19 |
| TS 29.558 vj40 | Enabling Edge Applications | Rel-19 |
