Valid

GB/T 34991-201712.5kHz TDMA channel based professional digital trunking communication system—Technical specifications for physical layer and data link layer of air interface (English PDF)

基于12.5kHz信道的时分多址（TDMA）专用数字集群通信系统空中接口物理层及数据链路层技术规范

Preview PDF

This is a limited preview

Buy now to download the full PDF (104 pages)

Need quotation for your management?

Get a formal quotation for GB/T 34991-2017 in 30 minutes.

Issued by

SAMR; SAC

Level / Type

National · Recommended

Issue date

November 1, 2017

Implementation date

February 1, 2018

Scope

GB/T 34991-2017 is the English-translated version of 基于12.5kHz信道的时分多址（TDMA）专用数字集群通信系统空中接口物理层及数据链路层技术规范.

GB/T 34991-2017 is the Chinese standard "12.5kHz TDMA channel based professional digital trunking communication system—Technical specifications for physical layer and data link layer of air interface".

Its scope clause reads: This standard specifies the 12.5kHz channel-based time division multiple access (TDMA) dedicated digital trunking communication system air interface physical layer and Data link layer technical specifications, including the overall protocol architecture, modulation, frame structure, channel codec and so on.

This standard applies to the frequency range of 30MHz ~ 1GHz based on 12.5kHz channel time division multiple access (TDMA) dedicated digital Cluster communication system (hereinafter referred to as "cluster system"). Its clauses include terms, definitions and abbreviations.

Found what you need?

Document preview — GB/T 34991-2017

National Standard of the People's Republic of China

ICS: 33.060.99
Classification: M 36

Issued by: State Administration for Market Regulation; Standardization Administration of the PRC

Foreword
Introduction
1 Scope
2 Normative references
3 Terms, definitions and abbreviations
3.1 Terms and definitions
3.2 Abbreviations
4 Overview
4.1 protocol architecture
4.2 Time Division Multiple Access Frame Structure
4.3 timing reference
4.4 Basic channel type
5 physical layer
5.1 General parameters
5.2 Modulation
6 Data Link Layer Protocol Description
6.1 Data Link Layer Timing
6.2 Channel Access
7 data link layer burst format
7.1 Data Link Layer Burst Format Overview
7.2 Voice Burst
7.3 Data and Control
7.4 Public Broadcasting Channel Burst
7.5 Reverse Channel Burst
8.1 Link Control Frame Structure
8.2 Control Signaling Frame Message Structure
8.3 Free Message Structure
8.4 multi-frame control message structure
8.5 End-to-End Voice Encryption Control Frame Structure
9.1 Data Fragmentation and Reassembly
9.2 Data Header Frame Structure
9.3 Data Frame Structure
10 protocol data unit
10.1 Voice, General Data and Public Broadcasting Channel PDUs
10.2 Data Related PDU Definitions
10.3 Data Link Layer Information Element Code
Appendix A (Normative) Timer Definition
Appendix B (Normative) Constant Definition
Appendix C (Normative) FEC and CRC coding
Appendix D (Normative) Idle Messages and Null Populate Embedded Message Definitions
Appendix E (Normative) Reverse Channel Timing

1 Scope

This standard specifies the 12.5kHz channel-based time division multiple access (TDMA) dedicated digital trunking communication system air interface physical layer and

Data link layer technical specifications, including the overall protocol architecture, modulation, frame structure, channel codec and so on.

This standard applies to the frequency range of 30MHz ~ 1GHz based on 12.5kHz channel time division multiple access (TDMA) dedicated digital

Cluster communication system (hereinafter referred to as "cluster system").

2 Normative references

The following documents for the application of this document is essential. For dated references, only the dated version applies to this standard quasi. For undated references, the latest edition (including all amendments) applies to this document.

GB/T 34992-2017 based on 12.5kHz channel time division multiple access (TDMA) dedicated digital trunking communication system air interface

Call control layer technical specifications

3 Terms, definitions and abbreviations

3.1 Terms and definitions

The following terms and definitions apply to this document.

3.1.1 Forward channel

In passthrough mode, the channel from the originator of the call to the receiver.

3.1.2 Backward channel

In passthrough mode, the channel from the call receiver to the initiator.

3.1.3

1. 1 mode 1. 1 mode

A business occupies a carrier mode.

3.1.4

2. 1 mode 2. 1 mode

Two different services use different time slots occupy a carrier mode.

3.1.5 Double slot data transmission 1

1modedatatransmission

Two slots of one carrier are occupied simultaneously in data transmission.

3.1.6 Direct mode directmodeoperation; DMO

Mobile station in the absence of any transit equipment and other one or more mobile stations to communicate mode of operation.

......
This preview omits tables, figures, formulas and parts of the technical clauses. The complete document — 104 pages — is available in the English PDF.

Referenced standards

Cited by

Similar standards

GB/T 40686-2021|GB/T 34992-2017|GB/T 47423-2026|GB/T 47425-2026|GB/T 47533-2026|GB/T 45434.1-2025

How to Download GB/T 34991-2017

1
Add to cart
Click "Download PDF" on this page and choose "Buy this standard". You can add more standards before checkout.
2
Checkout
Enter your email and billing details. Payment is processed securely by Stripe (cards or bank transfer). Prefer bank details? Request a quotation (min. order $300).
3
Instant delivery (0–9 sec)
Delivery is automatic: within seconds of payment you'll receive an email with a secure download link. The link stays valid for 72 hours.
4
Invoice included
A tax invoice is attached to the confirmation email. Need a custom invoice? Contact us.