| name | 3gpp-specifications |
| description | 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. |
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:
<series>.<spec>
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
https://www.3gpp.org/ftp/Specs/<YYYY>-<MM>/
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:
- Allocated next sequential spec number
- Example: If last spec in series 21 is 21.456, next is 21.457
- Continues until end of series or major release change
Example:
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™ document21.456.zip - Zip™ archive containing Word™ files21.456_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: <series>.<version>
Examples:
21.456.0 - Initial version of spec 21.45621.456.1 - First revision of spec 21.45622.101.3 - 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 concepts3gpp-working-groups - For understanding which WG owns which specs3gpp-change-request - For modification process via CRs3gpp-meetings - For understanding when specs are approved (at TSG plenaries)
Resources
Usage in Code
Finding Spec Files
import requests
from bs4 import BeautifulSoup
base_url = "https://www.3gpp.org/ftp/Specs/2018-12/"
response = requests.get(base_url)
soup = BeautifulSoup(response.text, "html.parser")
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
import re
def parse_spec_number(filename: str) -> tuple:
"""Parse spec number from filename."""
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
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