No relevant resource is found in the selected language.

This site uses cookies. By continuing to browse the site you are agreeing to our use of cookies. Read our privacy policy>Search

Reminder

To have a better experience, please upgrade your IE browser.

upgrade

S12700 V200R010C00 Configuration Guide - Device Management

This document describes the principles and configurations of the Device Management features, and provides configuration examples of these features.
Rate and give feedback:
Huawei uses machine translation combined with human proofreading to translate this document to different languages in order to help you better understand the content of this document. Note: Even the most advanced machine translation cannot match the quality of professional translators. Huawei shall not bear any responsibility for translation accuracy and it is recommended that you refer to the English document (a link for which has been provided).
Overview

Overview

Definition

The Precision Time Protocol (PTP) is a Precision Clock Synchronization Protocol for Networked Measurement and Control Systems, which is also called IEEE 1588 (1588 for short). This protocol enables standard Ethernet terminal devices to synchronize time and clock frequency from a clock source. 1588 includes 1588v1 and 1588v2. 1588v1 provides sub-millisecond precision time synchronization, and 1588v2 provides sub-microsecond precision time synchronization. 1588v2 is a time synchronization protocol. 1588v1 initially applied to high-precision time synchronization between devices and now is also used for frequency synchronization. 1588v1 has been replaced by 1588v2. Unless otherwise stated, PTP described in this document refers to 1588v2.

Purpose

The evolution of mobile networks to IP networks requires high-precision network clock synchronization between data communication devices. On an IP radio access network (RAN), the clock frequencies of base stations must be synchronized in a certain accuracy. Otherwise, clock slip occurs or even calls are interrupted when mobile phones are switched from a base station to another. Some wireless standards require phase synchronization in addition to frequency synchronization. Table 5-1 describes clock phase synchronization requirements.

Table 5-1  List of services requiring clock phase synchronization

Wireless Technology

Clock Frequency Accuracy Requirements

Clock Phase Synchronization Requirements

GSM

0.05 ppm

NA

WCDMA

0.05 ppm for a base station

NA

Pico 0.1 ppm

NA

TD-SCDMA

0.05 ppm

3 µs

CDMA2000

0.05 ppm

3 µs

WiMax FDD

0.05 ppm

NA

WiMax TDD

0.05 ppm

1 µs

Clock synchronization requirements of base stations with different standards can be met by various technologies, including synchronous Ethernet, Network Time Protocol (NTP), and PTP. Traditionally, base stations are directly connected to the global positioning system (GPS) for time synchronization. This method requires antennas to be installed in each base station, increasing project implementation and maintenance costs. The sub-second precision provided by NTP and sub-millisecond precision provided by 1588v1 cannot meet requirements of base stations for time synchronization. Synchronous Ethernet can only synchronize the clock frequency. PTP can provide sub-microsecond precision time synchronization with the assistance of hardware, meeting time synchronization requirements of base stations.

Benefits

PTP brings the following benefits:
  • Provides sub-microsecond precision time synchronization for transmission devices.
  • Reduces network construction and maintenance costs because no GPS receiver needs to be deployed or maintained for base stations.
  • Protects national security because PTP allows clock synchronization without the GPS.
Translation
Download
Updated: 2019-08-21

Document ID: EDOC1000142080

Views: 115097

Downloads: 149

Average rating:
This Document Applies to these Products
Related Version
Related Documents
Share
Previous Next