# 3gpp Specifications > TS and TR numbering, spec file formats, FTP directory structure, and accessing 3GPP specifications. Use when working with 3GPP specification numbering, finding spec files, or understanding spec directory organization. - Skill: `jr2804/3gpp-specifications` (Agent Skill) - Install (CLI): `npx skillmds@latest add jr2804/3gpp-specifications` - Raw SKILL.md: https://api.skillmd.com/api/skills/jr2804/3gpp-specifications/raw - Safety review: pending - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: Coding & Dev Tools - Author: jr2804 (https://skillmd.com/u/jr2804) - Updated: 2026-09-10 - Page: https://skillmd.com/skills/jr2804/3gpp-specifications --- # 3GPP Specifications ## Overview 3GPP specifications are the primary deliverables of the 3GPP partnership. They include: - **Technical Specifications (TS)** - Normative technical documents - **Technical Reports (TR)** - Informative studies and reports ## TS vs TR Distinction ### TS (Technical Specification) - **Purpose**: Define requirements, protocols, and interfaces - **Status**: Can be revised via Change Requests (CRs) - **Format**: Word™ (.doc) and Zip™ archives - **Numbering**: `21.456` (Series + Spec number) - **Authority**: Produced by WG or TSG ### TR (Technical Report) - **Purpose**: Informative studies, analysis, or background information - **Status**: Fixed at publication, can be revised via CRs - **Format**: Word™ (.doc) and Zip™ archives - **Numbering**: `TR 21.900` (TR + number) - **Authority**: Produced by WG or TSG ## Numbering Scheme ### Format **Two-digit series number + Three-digit spec number:** ```text . ``` **Examples:** - TS 21.456 - Series 21, spec 456 - TS 22.101 - Series 22, spec 101 - TR 21.900 - Technical Report 21, number 900 ### Specification Series Meanings Each two-digit series corresponds to a specific technical domain: | Series | Domain | Responsible TSG | |--------|--------|-----------------| | 21 | Requirements | SA | | 22 | Service aspects ("stage 1") | SA1 | | 23 | Technical realization ("stage 2") | SA2 | | 24 | Signalling protocols ("stage 3") - UE to network | CT1 | | 25 | Radio aspects (UTRA/UTRAN) | RAN | | 26 | CODECs | SA4 | | 27 | Data services | CT1 | | 28 | Signalling protocols ("stage 3") - RSS-CN | CT4 | | 29 | Signalling protocols ("stage 3") - Intra-CN | CT3/CT4 | | 31 | UE terminal conformance (USIM) | CT6 | | 32 | OAM&P and Charging | SA5 | | 33 | Security | SA3 | | 34 | UE and USIM test specifications | CT6/RAN5 | | 35 | Security algorithms | SA3 | | 36 | LTE (Evolved UTRA/E-UTRAN) | RAN | | 37 | Multiple radio access technology aspects | RAN | | 38 | 5G NR (New Radio) | RAN | **Key patterns:** - **Series 21-24**: Core requirements, services, architecture, signalling - **Series 25, 36-38**: Radio technologies (UTRA → LTE → NR) - **Series 31-35**: Security and terminal testing - **Series 26, 32**: Media codecs and network management ### Document Type Prefixes - **TS**: Technical Specifications (normative) - **TR**: Technical Reports (informative) ## Spec File Formats ### Word™ Format - **Purpose**: Formal specification document for review and change - **Extension**: `.doc` - **Structure**: Can include revision marks ("Track Changes") ### Zip™ Format - **Purpose**: Archive format for distribution - **Extension**: `.zip` - **Contents**: Word™ .doc files and additional resources ## FTP Directory Structure ### Root Directory ```text https://www.3gpp.org/ftp/Specs/-/ ``` **TSG Round Examples:** - RAN#110: `https://www.3gpp.org/ftp/Specs/2025-12/` - SA#110: `https://www.3gpp.org/ftp/Specs/2025-12/` - CT#110: `https://www.3gpp.org/ftp/Specs/2025-12/SpecslistexTSG/TSG110.htm` ### Directory Contents Each TSG round directory contains: - HTML index pages (SpecslistexTSG/TSG#>.htm) - Individual spec files (.doc, .zip) - Delta directories for parallel releases (e.g., 21.101d) - CR database and work item references ## Spec Categories ### Major Categories - **GSM (including GPRS and EDGE)** - **W-CDMA (including HSPA)** - **LTE** (including LTE-Advanced and LTE-Advanced Pro) - **5G** (including 5G NR Standalone) ### Spec Numbering Pattern **When a new spec is created:** 1. Allocated next sequential spec number 2. Example: If last spec in series 21 is 21.456, next is 21.457 3. Continues until end of series or major release change **Example:** ```text Series 21: 21.001, 21.002, 21.003, ..., 21.456 Series 22: 22.001, 22.002, 22.003, ..., 22.101 ``` ## Spec Files ### File Naming Convention Spec files follow 3GPP naming conventions: - Series number and spec number - Type identifier (TS/TR if applicable) - Version number (for revised versions) - Language code (if multilingual) **Example:** - `21.456.doc` - TS 21.456 Word™ document - `21.456.zip` - Zip™ archive containing Word™ files - `21.456_003.doc` - Version 003 revision ## Working Groups and Specs ### Working Group Responsibility Each Working Group is responsible for specifications in their domain: - **RAN**: Radio access technologies - **SA**: System architecture and services - **CT**: Core network and terminals ### Spec Assignment Specs are assigned to Working Groups based on their scope: - Technical specs typically belong to specific WGs - TSG plenaries approve specs for all TSGs ## Release Management ### MCC (Mobile Competence Centre) The MCC aims to make all specs available following TSG round as soon as possible. ### Target Dates - **Standard**: 4 weeks after TSG plenary - **Extra time**: Additional week for large volumes or holiday periods ## Version Control ### Spec Versions - **Initial version**: When first published as TS/TR - **Revisions**: Numbered versions created via Change Requests - **Dot notation**: Decimal numbering (e.g., 21.456.1) **Example Revision Numbering:** - Initial: 21.456 - First revision: 21.456.1 - Second revision: 21.456.2 - Third revision: 21.456.3 ### Version Number Format Spec version numbers follow the format: `.` **Examples:** - `21.456.0` - Initial version of spec 21.456 - `21.456.1` - First revision of spec 21.456 - `22.101.3` - Third revision of spec 22.101 ## Database References ### CR Database Change Requests are tracked in a database accessible via: - **Netovate Search**: Free CR database search tool - **Portal CR Database**: 3GPP portal CR database - **Spec History**: Each spec's history lists all approved CRs ### Work Items 3GPP Work Items define features to be developed. New specs and CRs are linked to Work Items. ## Key Points - **Spec Numbering is hierarchical**: Series → Spec Number - **TR numbers are separate series**: Use TR prefix for reports - **Revisions create new versions**: Each CR creates a new version number - **Multiple CRs can affect one spec**: All are merged into single version - **Mirror CRs require same WI code**: For specs in multiple releases ## Cross-References - `3gpp-releases` - For release structure and freeze concepts - `3gpp-working-groups` - For understanding which WG owns which specs - `3gpp-change-request` - For modification process via CRs - `3gpp-meetings` - For understanding when specs are approved (at TSG plenaries) ## Resources - **3GPP Official**: - **3GPP Portal**: - **3GPP Work Plan**: - **MCC Info**: Available in spec list tables ## Usage in Code ### Finding Spec Files ```python import requests from bs4 import BeautifulSoup # FTP directory for Release 18 base_url = "https://www.3gpp.org/ftp/Specs/2018-12/" response = requests.get(base_url) soup = BeautifulSoup(response.text, "html.parser") # Parse all spec files for link in soup.find_all("a", href=True): href = link.get("href") if href.endswith(".doc") or href.endswith(".zip"): print(f"Found spec: {href}") ``` ### Spec Number Parsing ```python import re def parse_spec_number(filename: str) -> tuple: """Parse spec number from filename.""" # Extract series number and spec number match = re.match(r"(\d{2})(\d{3})(\.doc|\.zip)", filename) if not match: return (None, None) return (match.group(1), match.group(2)) ``` ## Common Patterns ### Delta Directories For parallel releases (e.g., Rel-4/5/6), 3GPP creates delta directories containing only changed specs. **Purpose**: Reduce duplicate storage and make it easy to identify what's new in each release. ## Versioning in Practice - **Dot notation**: Use decimal versions for clarity (e.g., 21.456.1) - **Editorial changes**: Occasionally updated by MCC, not versioned - **Major/minor changes**: Some specs have major version increments between releases ## Related Documents - **Versioning Scheme**: - **Work Items**: