Description
JavaScript Object Notation (JSON) is a text-based, language-independent data format using human-readable text to represent attribute–value pairs and arrays. In 3GPP, starting from Release 12 and heavily adopted in the 5G core (5GC) from Release 15, JSON is the primary data serialization format for HTTP/2-based Service-Based Interfaces (SBIs) between Network Functions (NFs). It works by structuring data as collections of name/value pairs (objects) and ordered lists of values (arrays), transmitted as UTF-8 encoded text. Key architectural components include JSON Schema for defining data structures in OpenAPI specifications, and its use within HTTP/2 messages for operations like NF discovery, registration, and service invocation. The JSON payloads carry critical information such as NF profiles, subscription data, policy rules, and session management contexts. Its role is central to the stateless, modular 5G core architecture, enabling efficient, flexible, and developer-friendly machine-to-machine communication. Specifications detail media type usage (application/json), encoding rules, and mandatory/optional fields for numerous service operations.
Purpose & Motivation
JSON was adopted in 3GPP to provide a simpler, more efficient alternative to XML for data interchange in network APIs, particularly with the shift to cloud-native, service-based architectures in 5G. Previous approaches using XML or ASN.1 PER could be verbose and complex to parse, slowing development and processing. JSON solves this by offering a lightweight, easily parsed format that aligns with modern web development practices, reducing overhead and improving interoperability in RESTful APIs. The historical motivation was the need for agile service exposure and management in LTE/EPC (starting in Rel-12 for certain interfaces) and its full embrace for 5G SBI to support network slicing, automation, and rapid service deployment.
Release Timeline
Detected Changes Across Releases
from 3GPP Change RequestsSpecific changes extracted from the „Change history“ tables of 3GPP specifications (31 CRs across 5 releases). Complements the general historical overview above with the evidence-based evolution of this function.
In Release 15, JSON was introduced as a structured data format for several key 3GPP domains, specifically for the NR (New Radio), 5GC (5G Core), and NS (Network Slicing) Stage 3 definitions to ensure alignment with Stage 2. The release also updated the 5G and generic NRM (Network Resource Model) solution sets to formally support JSON, including defining its structure for queries and data handling.
- Update Stage 3 JSON definition of NR to align with Stage 2 content TS 28.541CR0006
- Update Stage 3 JSON definition of 5GC to align with Stage 2 content TS 28.541CR0009
- Update Stage 3 JSON definition of NS to align with Stage 2 content TS 28.541CR0012
- Update 5G JSON Solution Set to align with generic NRM TS 28.541CR0062
- Update Generic NRM Solution Set to support JSON TS 28.623CR0020
- JSON structure in query and missing data type reference TS 29.505CR0010
+ 1 more changes
In Release 16, the primary new development for JSON was the generation of standardized JSON definitions for multiple Network Resource Models (NRMs), including those for 5GC, generic NRM, Slice, and NR, based on a new style guideline. This established a consistent schema for managing network resources via data interfaces. Furthermore, the release formally referenced and incorporated the "draft-newton-json-content-rules" to govern JSON usage within the specifications.
- Update JSON definitions of ServiceProfile NRM TS 28.541CR0199
- generate JSON definition for 5GC NRM based on new style guideline TS 28.541CR0149
- generate JSON definition for generic NRM based on new style guideline TS 28.623CR0026
- generate JSON definition for Slice NRM based on new style guideline TS 28.541CR0157
- generate JSON definition for NR NRM based on new style guideline TS 28.541CR0158
- Reference update: draft-newton-json-content-rules TS 29.250CR0015
+ 1 more changes
In Release 17, the JSON function was enhanced with formal support for the "JSON Patch" and "JSON Merge Patch" encoding methods to describe changes to resources. The release introduced corrections and clarifications for these patches, including the encoding of binary attributes, the proper use of the test operation, and the definition that a JSON Merge Patch document is a partial resource representation. It also specified the handling of redirect responses using the "application/json" media type.
- Description of JSON body with "JSON Patch" encoding of changes TS 29.122CR0556
- Correcting "JSON Patch" encoding of changes TS 29.122CR0497
- Encoding of binary attributes in JSON objects TS 29.503CR0688
- Redirect responses with "application/json" media type TS 29.514CR0306
- Redirect responses with "application/json" media type TS 29.520CR0297
- Redirect responses with "application/json" media type TS 29.521CR0107
+ 7 more changes
In Release 18, the 3GPP specification introduced clarifications and specific handling rules for JSON, including the content and structure of JSON Patch requests and the treatment of invalid JSON values. These updates provided more precise definitions for JSON-based data interactions within the framework. The enhancements were part of broader support for interfaces like JSON over WebSocket, as referenced in the architectural options.
In Release 19, the new JSON-related function specifically addresses the formatting of JSON objects and arrays of JSON objects in query parameters. This enhancement provides a standardized method for structuring JSON data within HTTP requests, complementing existing interface options like JSON over WebSocket that were already supported. The update ensures consistent data handling for web-based interfaces without impacting other defined architectural components.
- Formatting of JSON objects and arrays of JSON objects in query parameters TS 29.122CR0890
Explore further
Broader topics and technologies where JSON plays a role.
Defining Specifications
3GPP specifications that define or reference JSON, with the latest known release. Sourced from the 3GPP document catalog — see methodology.
| Specification | Title | Release |
|---|---|---|
| TS 23.701 vc00 | WebRTC Access to IMS Architecture Study | Rel-12 |
| TS 23.722 vf10 | Common API Framework (CAPIF) for 3GPP Northbound APIs | Rel-15 |
| TS 24.559 vj41 | Application Data Analytics Enablement Services | Rel-19 |
| TS 26.119 vj00 | XR Media Capabilities for AR Devices | Rel-19 |
| TS 26.347 vj00 | MBMS Transport Protocol and API (TRAPI) | Rel-19 |
| TS 26.510 vj10 | Media Delivery APIs for 5GMS and RTC Systems | Rel-19 |
| TS 26.512 vj10 | 5G Media Streaming Protocols & APIs | Rel-19 |
| TS 26.517 vj10 | 5G MBS User Service Protocols and Formats | Rel-19 |
| TS 26.804 vj10 | 5G Media Streaming Extensions Study | Rel-19 |
| TS 26.841 vj00 | Study on Media Messaging Enhancements | Rel-19 |
| TS 26.854 vj00 | Study on Haptics in 5G Media Services | Rel-19 |
| TR 26.857 vi00 | Technical Report on Media Service Enablers | Rel-18 |
| TR 26.955 vj00 | Video Codec Analysis for 5G Services | Rel-19 |
| TR 26.956 vj01 | Beyond 2D Video Formats & Codecs Study | Rel-19 |
| TR 26.998 vj00 | 5G AR/MR Glasses Integration Study | Rel-19 |
| TS 28.536 vj20 | Management services for communication service assurance | Rel-19 |
| TS 28.541 vk00 | 5G Network Resource Model (NRM) Stage 2/3 | Rel-20 |
| TS 28.623 vk00 | Generic NRM IRP Solution Set Definitions | Rel-20 |
| TS 29.116 vj00 | REST-based protocol for xMB reference point | Rel-19 |
| TS 29.122 vj40 | T8 Reference Point for Northbound APIs | Rel-19 |
| TS 29.155 vj00 | REST-based St Reference Point Protocol | Rel-19 |
| TS 29.222 vj40 | Common API Framework (CAPIF) for 3GPP Northbound APIs | Rel-19 |
| TS 29.250 vj00 | Nu Reference Point Stage 3 Specification | Rel-19 |
| TS 29.251 vj00 | Gw/Gwn Reference Points Stage 3 Specification | Rel-19 |
| TS 29.502 vj50 | 5G System; Nsmf Service Based Interface; Stage 3 | Rel-19 |
| TS 29.503 vj50 | UDM Service Based Interface Stage 3 | Rel-19 |
| TS 29.505 vj50 | UDR Service for Subscription Data Usage | Rel-19 |
| TS 29.507 vj40 | 5G Access & Mobility Policy Control Service | Rel-19 |
| TS 29.508 vj40 | 5G Session Management Event Exposure Service | Rel-19 |
| TS 29.514 vj40 | 5G System; Policy Authorization Service; Stage 3 | Rel-19 |
| TS 29.518 vj50 | AMF Service Based Interface Protocol | Rel-19 |
| TS 29.519 vj40 | UDR Usage for Policy & Exposure Data | Rel-19 |
| TS 29.520 vj40 | 5G Network Data Analytics Services Stage 3 | Rel-19 |
| TS 29.521 vj40 | 5G Binding Support Management Service Stage 3 | Rel-19 |
| TS 29.525 vj40 | 5G UE Policy Control Service Stage 3 | Rel-19 |
| TS 29.534 vj20 | 5G Access & Mobility Policy Authorization Service | Rel-19 |
| TS 29.540 vj40 | Nsmsf Service Based Interface Stage 3 | Rel-19 |
| TS 29.549 vj40 | SEAL API Specification for Vertical Applications | Rel-19 |
| TS 29.550 vj20 | 5G Steering of Roaming Service Based Interface | Rel-19 |
| TS 29.551 vj30 | 5G PFD Management Service Stage 3 | Rel-19 |
| TS 29.554 vj10 | 5G Background Data Transfer Policy Control Service | Rel-19 |
| TS 29.562 vj40 | HSS Services for IMS & GBA Interworking | Rel-19 |
| TS 29.563 vj30 | TS 29563: Nhss services for HSS-UDM interworking | Rel-19 |
| TS 29.817 vc10 | Study on XML-based Rx interface for PCC | Rel-12 |
| TS 29.890 vg00 | CT3 5G System Technical Report | Rel-16 |
| TS 29.891 vg00 | CT4 Aspects of 5G System Phase 1 | Rel-16 |
| TS 32.158 vk00 | Management and Orchestration REST Solution Sets | Rel-20 |
| TS 32.866 vf00 | REST, HTTP, JSON for Management Interfaces | Rel-15 |
| TS 33.117 vk00 | Catalogue of General Security Assurance Requirements | Rel-20 |
| TS 33.122 vj20 | Security Architecture for CAPIF | Rel-19 |
| TS 33.180 vk00 | Security of Mission Critical (MC) Service | Rel-20 |
| TS 33.514 vk00 | 5G Security Assurance for UDM | Rel-20 |
| TS 33.517 vk00 | 5G Security Assurance Specification (SCAS) | Rel-20 |
| TR 33.841 vg10 | Security aspects; Study on 256-bit algorithms for 5G | Rel-16 |
| TS 33.880 vf10 | Security Study for Enhanced Mission Critical Services | Rel-15 |
| TR 33.938 vj10 | 3GPP Cryptographic Inventory for 5G | Rel-19 |
