Clock Synchronization Solution
Classific
ation
Clock
Synchronizat
ion Solution
Description
Frequenc
y
synchroni
zation
BITS clock
For GSM and WCDMA base stations that only require
frequency synchronization, BITS clocks are transmitted to
base stations to achieve network-wide clock synchronization
when OLTs have BITS input clocks.
E1/STM-1 line
clock
For GSM and WCDMA base stations that only require
frequency synchronization, E1/STM-1 line clocks are used to
achieve clock synchronization when OLTs transmit services
upstream to SDH networks through E1/STM-1 ports.
Synchronous
Ethernet clock
For GSM and WCDMA base stations that only require
frequency synchronization, clocks restored from code streams
on Ethernet links are used to achieve network-wide clock
synchronization when OLTs transmit services upstream to
PSN networks through GE/10GE ports.
Time
synchroni
zation
1PPS+ToD
time
OLTs receive time information through 1PPS+TOD ports.
The time information is transmitted from external time servers
(such as Huawei SYNLOCK T6020) that obtain standard time
synchronization information using GPS. This solution is
recommended for 3G and LTE stations.
1588V2 time
The OLT obtains the 1588v2 time by using the upstream
network interface (the time is transmitted by the upstream
network hop by hop). Then, the OLT transmits the time to the
ONU through the GPON line. After recovering the time, the
ONU transmits the time to the base station by means of the
1588v2 or time interface.
NOTE
The priority of recommended frequency synchronization solutions is as follows: BITS clock > line clock >
synchronous Ethernet clock. Select a clock source based on the actual conditions of COs.
Recommended Clock Synchronization Solutions for Different Base Station Access
Scenarios
Scenario
Recommended Clock Synchronization Solution
E1 base station access service
(in Native TDM mode)
BITS clock
E1/STM-1 line clock
T1 base station access service
(in GPON SAToP mode)
BITS clock
E1/STM-1 line clock
SmartAX MA5600T/MA5603T/MA5608T Multi-service
Access Module
Commissioning and Configuration Guide
14 FTTM Configuration (Base Station Access)
Issue 01 (2014-04-30)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
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