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
- 3GPP Official: https://www.3gpp.org/
- 3GPP Portal: https://portal.3gpp.org/
- 3GPP Work Plan: https://www.3gpp.org/specifications-technologies/3gpp-work-plan/
- MCC Info: Available in spec list tables
Usage in Code
Finding Spec Files
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
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