1. Overview of CDMA Synchronisation

CDMA, or Code Division Multiple Access, denotes a wireless communication technology developed from spread-spectrum multiple-access digital communication techniques. In China, it is primarily employed within the 800MHz mobile telephone system.

The time source for CDMA base stations is derived from GPS and BeiDou. Through an integrated cardless module, it communicates with the CDMA base station network to receive time information, thereby synchronising the electronic clock's timekeeping and displaying the running time. As global GPS or BeiDou time information is identical (accurate to within one second over 300,000 years), this achieves synchronised time display functionality.

CDMA network clocks feature high precision, robust functionality, excellent stability, no cumulative error, immunity to environmental constraints such as climate or geography, high cost-effectiveness, simple operation, and maintenance-free operation. They function fully automatically and intelligently, making them suitable for unattended environments.

2. Applications of CDMA Clocks

(1) Various time synchronisation systems acquiring standard time via satellite synchronisation;

(2) Computer networks, computer application systems, and process control management systems;

(3) Time unification systems and various time display screens for power plants (stations) and grid dispatch centres;

(4) E-commerce systems, B2B online systems, and database storage and maintenance systems;

(5) Industrial sectors including power generation, finance, mobile communications, petroleum, electricity, transportation, manufacturing, and national defence.

3. Advantages and Disadvantages of CDMA Synchronisation

Advantages: The CDMA receiver module, following secondary development, can acquire time information without requiring a mobile SIM card. As it lacks data communication functionality, users need not concern themselves with ongoing usage fees. This product facilitates straightforward deployment in any location with CDMA signal coverage, proving particularly suitable for network communication rooms where outdoor GPS/BeiDou antenna installation is impractical. Furthermore, the indoor placement of the CDMA antenna simplifies installation and eliminates the need for lightning protection measures.

We employ our proprietary CDMA timing module, certified by the National Time Service Centre. This module delivers high synchronisation accuracy with reliable, stable signal reception, achieving precision within 10 milliseconds. Embedded within standard clocks, it replaces traditional master clock-based timing acquisition. Each clock independently retrieves time signals from the NTP network once per minute, ensuring temporal accuracy.

Given the potential discontinuation of the CDMA system within the next five years, our company has already developed NB-IoT clocks as replacements.