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eRAN
Uu based Soft Synchronization
Feature Parameter Description
Issue 02
Date 2015-04-30
HUAWEI TECHNOLOGIES CO., LTD.
7/25/2019 Uu Based Soft Synchronization(ERAN8.1_02)
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Copyright Huawei Technologies Co., Ltd. 2015. All rights reserved.
No part of this document may be reproduced or transmitted in any form or by any means without prior written
consent of Huawei Technologies Co., Ltd.
Trademarks and Permissions
and other Huawei trademarks are trademarks of Huawei Technologies Co., Ltd.
All other trademarks and trade names mentioned in this document are the property of their respective
holders.
Notice
The purchased products, services and features are stipulated by the contract made between Huawei and the
customer. All or part of the products, services and features described in this document may not be within thepurchase scope or the usage scope. Unless otherwise specified in the contract, all statements, information,
and recommendations in this document are provided "AS IS" without warranties, guarantees or
representations of any kind, either express or implied.
The information in this document is subject to change without notice. Every effort has been made in the
preparation of this document to ensure accuracy of the contents, but all statements, information, and
recommendations in this document do not constitute a warranty of any kind, express or implied.
Huawei Technologies Co., Ltd.
Address: Huawei Industrial Base
Bantian, Longgang
Shenzhen 518129
People's Republic of China
Website: http://www.huawei.com
Email: [email protected]
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Contents
1 About This Document.................................................................................................................. 1
1.1 Scope.............................................................................................................................................................................. 1
1.2 Intended Audience..........................................................................................................................................................1
1.3 Change History...............................................................................................................................................................1
1.4 Differences Between eNodeB Types..............................................................................................................................2
2 Overview......................................................................................................................................... 3
2.1 Background.....................................................................................................................................................................3
2.2 Introduction.................................................................................................................................................................... 4
2.3 Benefits...........................................................................................................................................................................4
2.4 Architecture.................................................................................................................................................................... 4
3 Technical Description...................................................................................................................6
3.1 Overview........................................................................................................................................................................ 6
3.2 Initial Synchronization................................................................................................................................................... 73.2.1 Determining the Synchronization Zone and eNodeB Pairs.......................................................................................10
3.2.2 Collecting Time Differences Between Paired eNodeBs............................................................................................12
3.2.3 Adjusting the Time on Non-reference eNodeBs Based on the Time on the Reference eNodeB.............................. 14
3.3 Synchronization Tracing...............................................................................................................................................15
3.4 Synchronization Maintenance...................................................................................................................................... 15
3.5 Absolute Time Synchronization for eMBMS...............................................................................................................17
4 Related Features...........................................................................................................................19
5 NetworkImpact........................................................................................................................... 21
6 Engineering Guidelines............................................................................................................. 22
6.1 When to Use LOFD-080216 Uu based Soft Synchronization......................................................................................22
6.2 Required Information................................................................................................................................................... 22
6.3 Planning........................................................................................................................................................................23
6.3.1 RF Planning...............................................................................................................................................................23
6.3.2 NetworkPlanning......................................................................................................................................................23
6.3.3 Hardware Planning.................................................................................................................................................... 24
6.4 Feature Deployment..................................................................................................................................................... 24
6.4.1 Process.......................................................................................................................................................................24
6.4.2 Requirements.............................................................................................................................................................24
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6.4.3 Data Preparation........................................................................................................................................................ 25
6.4.4 Precautions.................................................................................................................................................................35
6.4.5 Activation.................................................................................................................................................................. 35
6.4.5.1 7.4.5.1 Using the CME to Perform Batch Configuration for Newly Deployed eNodeBs......................................36
6.4.5.2 Using the CME to Perform Batch Configuration for Existing eNodeBs............................................................... 36
6.4.5.3 Using the CME to Perform Single Configuration.................................................................................................. 37
6.4.5.4 Using MML Commands.........................................................................................................................................38
6.4.5.5 MML Command Examples.................................................................................................................................... 39
6.4.6 Activation Observation..............................................................................................................................................41
6.4.7 Deactivation...............................................................................................................................................................43
6.4.7.1 Using CME to Perform Batch Configuration.........................................................................................................43
6.4.7.2 Using the CME to Perform Single Configuration.................................................................................................. 44
6.4.7.3 Using MML Commands.........................................................................................................................................44
6.4.7.4 MML Command Examples.................................................................................................................................... 44
6.4.8 Reconfiguration......................................................................................................................................................... 44
6.5 Performance Monitoring...............................................................................................................................................44
6.5.1 Time Difference Measurements Between eNodeBs in eNodeB Pairs.......................................................................44
6.5.2 Absolute Values of Average Time Difference Changes Between eNodeBs..............................................................44
6.5.3 Absolute Values of Average Time Differences Between eNodeBs...........................................................................45
6.6 ParameterOptimization................................................................................................................................................46
6.7 Troubleshooting............................................................................................................................................................46
6.7.1 Related Alarms.......................................................................................................................................................... 46
6.7.2 Handling Exceptions on Message Reporting.............................................................................................................47
7 Parameter.......................................................................................................................................49
8 Counters........................................................................................................................................ 65
9 Glossary.........................................................................................................................................67
10 Reference Documents...............................................................................................................68
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1About This Document
1.1 Scope
This document describes LOFD-080216 Uu based Soft Synchronization, including its
technical principles, related features, network impact, and engineering guidelines.
This document applies to the following types of eNodeBs.
eNodeB Type Model
Macro 3900 series eNodeB
NOTE
Currently, LOFD-080216 Uu based Soft Synchronization does not apply to multimode base stations.
1.2 Intended Audience
This document is intended for personnel who:
l Need to understand the features described herein
lWork with Huawei products
1.3 Change History
This section provides information about the changes in different document versions. There are
two types of changes:
l Feature change
Changes in features and parameters of a specified version as well as the affected entities
l Editorial change
Changes in wording or addition of information and any related parameters affected byeditorial changes. Editorial change does not specify the affected entities.
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eRAN8.1 02 (2015-04-30)
This issue includes the following changes.
Change Type Change
Description
Parameter Change Affected Entity
Feature change None None -
Editorial change Revised descriptions
in 6.4.6 Activation
Observation.
None -
eRAN8.1 01 (2015-03-23)
This issue does not include any changes.
eRAN8.1 Draft A (2015-01-15)
This document is created for eRAN8.1.
1.4 Differences Between eNodeB Types
Feature Support by Macro, Micro, and LampSite Base Stations
Feature ID Description Supported byMacro eNodeBs Supportedby MicroeNodeBs
Supported byLampSiteeNodeBs
LOFD-080216 Uu based Soft
Synchronizatio
n
Yes No No
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2Overview
2.1 Background
Many LTE features pose high requirements on time synchronization.
l LOFD-070208 Coordinated Scheduling based Power Control (Cloud BB)
In most cases, neighboring evolved universal terrestrial radio access network (E-
UTRAN) cells on the same frequency interfere with one another. To reduce the
interference, the transmit power for downlink (DL) channels can be coordinated to
increase the signal to interference plus noise ratio (SINR) of cell edge user equipment
(UEs) and therefore improve network performance. LOFD-070208 Coordinated
Scheduling based Power Control (Cloud BB) is introduced to coordinate TTI-specific
transmit power configurations in individual cells. It reduces inter-cell interference based
on collaboration between scheduling and power control. (TTI is short for transmission
time interval.) This feature requires time synchronization between eNodeBs connecting
to the same universal switching unit (USU).
l LAOFD-002001 Static TDM eICIC
In an intra-frequency heterogeneous network (HetNet), micro eNodeBs supplement
network coverage and increase network capacity. Macro cells and micro cells cause
interference on each other. LAOFD-002001 Static TDM eICIC decreases interference
between macro cells and micro cells by coordinating available time-domain resources of
neighboring cells, thereby increasing downlink performance and throughput of CEUs in
an intra-frequency HetNet. TDM and eICIC are short for time division multiplexing and
enhanced inter-cell interference coordination, respectively TDM eICIC requires time
synchronization between macro cells and micro cells involved in interference
coordination.
l LOFD-070220 eMBMS Phase 1 based on Centralized MCE Architecture
This feature enables one data source to transmit data to multiple UEs based on network
resource sharing. eMBMS is short for evolved multimedia broadcast/multicast service.
eMBMS improves the resource utilization rate and enables multimedia services to be
broadcast in high data rates. eMBMS requires time synchronization between eNodeBs.
To support eMBMS in eNodeBs within 3 km from each other in the Multimedia
Broadcast multicast service Single Frequency Network (MBSFN) area, the time
difference between eNodeBs must be less than 3 microseconds (s).
l LAOFD-080201 Inter-eNodeB CA based on Relaxed backhaul
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According to 3GPP specifications, LTE-Advanced intends to provide the service data
rate as high as 1 Gbit/s in the downlink. Because frequency spectrums are in shortage
and bandwidths granted to operators are non-contiguous, a single frequency band can
hardly provide the bandwidths required by LTE Advanced. Therefore, 3GPP Release 10
TR36.913 introduced carrier aggregation (CA) to provide a maximum of 100 MHz
bandwidth by aggregating multiple contiguous or non-contiguous carriers. In addition,
CA improves the usage of scattered frequency spectrum, especially in refarming
scenarios. LAOFD-080201 Inter-eNodeB CA based on Relaxed backhaul requires that
time must be synchronized between eNodeBs with CA implemented. Specifically,
downlink CA requires the time accuracy of 1.5 s.
Currently, eNodeBs support features related to time synchronization such as LBFD-00300503
GPS Synchronization and LOFD-00301302 IEEE1588 V2 Clock Synchronization.
LBFD-00300503 GPS Synchronization requires GPS, which increases hardware deployment
cost. LOFD-00301302 IEEE1588 V2 Clock Synchronization requires transport devices to
support the IEEE1588 V2 protocol, which may require transport network reconstruction.
Compared with the preceding two features, LOFD-080216 Uu based Soft Synchronization
supports time synchronization at lower cost without the need for transmission networkreconstruction.
2.2 Introduction
Uu-based soft synchronization achieves time synchronization between eNodeBs by adjusting
time differences between the eNodeBs based on software measurement results. In Uu-based
soft synchronization, the time difference between two neighboring eNodeBs can be obtained
during inter-eNodeB handovers or physical random access channel (PRACH) measurements
initiated by CEUs or UEs in inter-eNodeB handovers. A centralized control node (for
example, the eCoordinator) collects all time differences reported by eNodeBs within the area
within which the coordination feature is applied (this area is called the Uu-based softsynchronization zone and also referred to as synchronization zone in this document),
calculates the time adjustment quantity of each eNodeB against the reference eNodeB, and
adjusts the time of all eNodeBs at the same time. In this way, all eNodeBs within the
synchronization zone achieve time synchronization with the reference eNodeB. The Uu based
Soft Synchronization feature is enabled only after eNodeBs achieve frequency
synchronization based on synchronous Ethernet. Frequency synchronization enables the
stability of time synchronization between eNodeBs.
2.3 Benefits
l The Uu based Soft Synchronization feature provides less than or equal to 3-s timesynchronization accuracy, which satisfies the demanding time synchronization
requirements of coordination features such as TDM eICIC and CSPC.
l In scenarios with synchronous Ethernet deployed, compared with LBFD-00300503 GPS
Synchronization and LOFD-00301302 IEEE1588 V2 Clock Synchronization, the Uu
based Soft Synchronization feature supports time synchronization at lower cost without
the need for transmission network reconstruction.
2.4 Architecture
Figure 2-1shows the network architecture for deploying LOFD-080216 Uu based SoftSynchronization. The architecture includes the following network elements (NEs): eNodeBs
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(one eNodeB functions as the reference eNodeB), a centralized control node (the
eCoordinator, which is abbreviated as eCo in the figure), and UEs in inter-eNodeB handovers
or CEUs under the neighboring eNodeBs.
Figure 2-1Network architecture for deploying the Uu based Soft Synchronization feature
l Reference eNodeB
The reference eNodeB works as the time synchronization source in a synchronization
zone. Other eNodeBs maintain time synchronization with the reference eNodeB.
Generally, an eNodeB located at the center of the synchronization zone and equippedwith the GPS is selected as the reference eNodeB.
l Centralized control node
A centralized control node is the control center for deploying this feature. A centralized
control node delivers configuration commands to eNodeBs, collects time differences
between eNodeBs, and calculates time adjustment quantity for each eNodeB. Currently,
the eCoordinator works as the centralized control node.
l UEs in inter-eNodeB handovers or CEUs under neighboring eNodeBs
A UE in inter-eNodeB handovers: The UE assists the serving eNodeB to collect the time
difference between the eNodeB and its neighboring eNodeB based on inter-eNodeB
handovers.
A CEU under neighboring eNodeBs: The UE assists the serving eNodeB to collect the
time difference between the eNodeB and its neighboring eNodeB based on random
access requests to the neighboring eNodeBs.
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3Technical Description
3.1 Overview
The overall procedure of Uu-based soft synchronization includes initial synchronization and
synchronization tracing. Initial synchronization includes the following three steps:
1. Determining the synchronization zone and neighboring eNodeB pairs
2. Collecting time differences between each pair of eNodeBs
3. Adjusting the time on non-reference eNodeBs based on the time on the reference
eNodeB
Synchronization tracing includes the following two steps:
1. Collecting time differences between each pair of eNodeBs
2. Adjusting the time on non-reference eNodeBs based on the time on the reference
eNodeB
After initial synchronization and synchronization tracing are complete, the eNodeBs enter the
synchronization maintenance state to maintain time accuracy.
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Figure 3-1Procedure for Uu-based soft synchronization
3.2 Initial Synchronization
After LOFD-080216 Uu based Soft Synchronization is enabled, a non-reference eNodeBperforms initial synchronization to generally adjust the time difference between the eNodeB
and the reference eNodeB. General adjustment is performed once only. The methods for
measuring time differences between eNodeBs in eNodeB pairs differ depending on whether a
UE is a UE in eNodeB boundaries or a UE involved in inter-eNodeB handovers.
l Figure 3-2shows the procedure that UEs involved in inter-eNodeB handovers measure
time differences between eNodeBs in eNodeB pairs.
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Figure 3-2Time difference measurement performed by UEs involved in inter-eNodeB
handovers
a. The source eNodeB sends a Handover Request message to the target eNodeB.
Then, the source eNodeB sends the Random Access Command to a UE. The UE
sends a random access preamble to the source eNodeB, based on which the source
eNodeB obtains the delay in transmitting the preamble from the UE to the source
eNodeB. The delay is recorded as Tpa1.
b. After receiving the Handover Request message, the target eNodeB sends the source
eNodeB a Handover Request Acknowledgement message. The source eNodeB
enables the preamble blind detection receive function and sends a handover
command to the UE.
c. The UE sends a random access preamble to the target eNodeB. The source eNodeB
blindly detects the preamble sent by the UE and obtains the delay in transmitting
the preamble from the UE to the target eNodeB. The delay is recorded as Tneigh.
d. The target eNodeB detects the preamble sent by the UE and obtains the delay in
transmitting the preamble from the UE to the target eNodeB. The delay is recordedas Taccess. The target eNodeB sends a Random Access Command message to the
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UE. The UE initiates a random access preamble to the target eNodeB. The target
eNodeB obtains the delay in transmitting the preamble from the UE to the target
eNodeB. The delay is recorded as Tpa2.
e. The target eNodeB sends the UE Context Release message to the source eNodeB.
After receiving the message, the source eNodeB stops preamble blind detection.f. The time difference between the target eNodeB and the source eNodeB is calculated
based on the following formula: Tdif = (TaccessTneigh) - (Tpa1 - Tpa2). In the
formula, "(Tpa1 - Tpa2)" indicates the difference between the delays in transmitting
UE's signals to the two eNodeBs.
l Figure 3-3shows the procedures that UEs in eNodeB boundaries measure time
differences between eNodeBs in eNodeB pairs.
Figure 3-3Time differences measured by UEs in eNodeB boundaries performing
random accesses
a. The source eNodeB sends a Blind Detect Request message to the neighboring
eNodeB. The neighboring eNodeB enables the preamble blind detection and receivefunction for preambles sent by a UE (this UE is in eNodeB boundaries) and sends a
Blind Detect Response message to the source eNodeB.
b. The serving eNodeB sends a Random Access Request message to the UE. The UE
sends random access signals to the serving eNodeB. The neighboring eNodeB
blindly detects the preambles sent by the UE and obtains Tneigh, and then stops
blind detection. The neighboring eNodeB sends the serving eNodeB the Blind
Detect Result message, including the obtained Tneigh.
c. The serving eNodeB detects the preamble and obtains the Taccess. The time
difference between the serving eNodeB and the neighboring eNodeB (Tdif) is the
difference between Taccess and Tneigh. The time difference is measured in the unit
of Ts.
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NOTE
l One eCoordinator supports a maximum of 256 synchronization zones and a maximum of 5000
eNodeBs for Uu-based soft synchronization.
l eNodeB pairs are automatically added and then can be manually changed.
The eCoordinator adds synchronization zones by running the ADD AISSZONEcommand.
Parameters AISSZONE.FrequencyBand, AISSZONE.DLFrequency, and
AISSZONE.DLBandWidthare used to verify whether an eNodeB to be added belongs to the
synchronization zone. If one of the parameters CELL.FreqBand, CELL.DlEarfcn, and
CELL.DlBandwidthof any cell under the eNodeB has the same value as any of parameters
AISSZONE.FrequencyBand, AISSZONE.DLFrequency, and AISSZONE.DLBandWidth,
the eNodeB can be added to the synchronization zone.
The eCoordinator adds eNodeBs to the synchronization zone by running the ADD ENBAISS
command. You can specify a primary reference eNodeB and a secondary reference eNodeB
by running the ADD ENBAISScommand twice with the ENBAISS.BaseStationType
parameter set to PRIBASEand BAKBASE, respectively. You can also specify commoneNodeBs by running the ADD ENBAISScommand with the ENBAISS.BaseStationType
parameter set to NORMALBASE. If the primary reference eNodeB experiences exceptions
(such as the synchronous Ethernet is faulty or the eNodeB is powered off), the secondary
reference eNodeB functions as the reference clock source.
The eCoordinator activates the automatic eNodeB pairing calculation function by running the
ACT AISSNENBCALCcommand. After the automatic calculation, you can manually
change some eNodeB pairs by running the RMV AISSNENBor ADD AISSNENB
command.
Collecting information about eNodeB pairs
The eCoordinator starts to collect information about eNodeB pairs after the synchronization
zone is activated and the automatic eNodeB pairing calculation function is enabled (or the
eNodeB pairs are manually added). As shown in Figure 3-5, the eCoordinator sends an
AISS_INFO_REQ message to an eNodeB. The eNodeB sends the eCoordinator an
AISS_INFO_RSP message. This message includes IEs AISS eNB Info and Neighber eNB
List, which carry the basic information about the eNodeB and intra-frequency neighboring
eNodeB list, respectively.
Figure 3-5Collecting information about eNodeB pairs
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3.2.2 Collecting Time Differences Between Paired eNodeBs
When a UE is handed over between two paired eNodeBs, both eNodeBs detect the random
access preamble sent by the UE simultaneously. Each eNodeB records the time when the
random access preamble is detected, and the eNodeBs then calculate their time difference
based on the delays in transmitting the UE's signals to the two eNodeBs.
The ADD AISSZONEcommand can be executed on the eCoordinator to specify parameters
related to Uu-based soft synchronization. The AISSZONE.MeasureTimeparameter specifies
the start time for measuring time differences between each two paired eNodeBs in a
synchronization zone. The AISSZONE.MeasureLastparameter specifies the duration during
which time differences between each two paired eNodeBs in a synchronization zone are
measured. The AISSZONE.DetectAvoidSwitchparameter specifies whether preamble blind
detection can be performed during data transmission over PRACH frequency resources. If this
parameter is set to OFF(Off), preamble blind detection cannot be performed during data
transmission over PRACH frequency resources. In this case, uplink throughput is not affected,
but the preamble blind detection success rate may decrease. If this parameter is set to
ON(On), preamble blind detection can be performed during data transmission over PRACH
frequency resources. In this case, uplink throughput decreases slightly, and the preamble blind
detection success rate increases. This parameter is set to OFF(Off)by default. You are
advised to set this parameter to ON(On)if the preamble blind detection success rate is low.
However, do not set this parameter to ON(On)if the system bandwidth is less than or equal to
5 MHz.
The time differences between paired eNodeBs are measured based on eNodeB pairs in
synchronization levels in ascending order. The message flow between the eCoordinator and
eNodeBs during time difference measurement is as follows:
1. Starting time difference measurements
When the time on the eCoordinator approaches the time specified by the
AISSZONE.MeasureTimeparameter, time difference measurement starts. As shown in
Figure 3-6, the eCoordinator delivers the AISS_MEAS_START_REQ messages to the
eNodeBs, instructing each eNodeB to measure the time difference with its neighboring
eNodeB in each eNodeB pair. The AISS_MEAS_START_REQ message includes IEs AISS
Measure Type, AISS Cell Para, and AISS Measure Para. The IE AISS Measure Type indicates
the UE types in intra-frequency neighboring eNodeBs involved in time difference
measurements, including CEUs in inter-eNodeB handovers, CEUs, and UEs in inter-eNodeB
handovers.
l If both a local eNodeB and its neighboring eNodeB transmit power at average strength,
the IE AISS Measure Type is automatically set to the value indicating CEUs in inter-
eNodeB handovers.
l If a local eNodeB transmits power at average strength and its neighboring eNodeB
transmits power in low strength, the IE AISS Measure Type is automatically set to the
value indicating CEUs.
l If a local eNodeB transmits power at low strength and its neighboring eNodeB transmits
power at average strength, the IE AISS Measure Type is automatically set to the value
indicating UEs in inter-eNodeB handovers.
The IE AISS Measure Para includes parameters Mea Last Timeand Rsrp Shreshold, which
indicate the time difference measurement duration and RSRP threshold, respectively. After
starting time difference measurements, the eNodeBs send the eCoordinator the
AISS_MEAS_START_RSP messages, indicating whether the time difference measurementsare successful.
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NOTE
Only CEUs that newly access cells trigger time difference measurements.
Figure 3-6Starting time difference measurements
2. Updating parameters related to time difference measurements
The eCoordinator sends eNodeBs the AISS_MEAS_PARA_UPT messages including the IE
AISS Measure Para UPT, instructing eNodeBs to update parameters related to time difference
measurements. The IE AISS Measure Para UPT is used to update parameters Neighber eNB
ID(indicating ID of a neighboring eNodeB), Ho Rsrp Shreshold(indicating RSRP threshold
for inter-eNodeB handovers), and Ce Rsrp Shreshold(indicating RSRP threshold received
by CEUs).
Figure 3-7Updating parameters related to time difference measurements
3. Sending time difference measurement reports
After time difference measurements, eNodeBs send the eCoordinator the AISS_
MEASURE_RPT messages including the IE AISS Measure Report. The IE AISS Measure
Report includes the time difference between a local eNodeB and its neighboring eNodeB.
TimeDif is calculated by (Taccess - Tneigh), and the transmission delay Tp Dif is calculatedby (Tpa1 - Tpa2).
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Figure 3-8Sending time difference measurement reports
4. Stopping time difference measurementsAfter the time on some eNodeBs approaches the time specified by the
AISSZONE.MeasureLastparameter, the eCoordinator delivers the
AISS_MEAS_STOP_REQ messages to these eNodeBs including the IE AISS Measure Stop
Type, instructing these eNodeBs to stop time difference measurements. The IE AISS Measure
Stop Type includes the Neighber eNB Listparameter indicating the list of neighboring
eNodeBs that are required to stop time difference measurements.
Figure 3-9Stopping time difference measurements
3.2.3 Adjusting the Time on Non-reference eNodeBs Based on theTime on the Reference eNodeB
After collecting time differences between paired eNodeBs in a synchronization zone, the
eCoordinator calculates the time differences between each eNodeB and the reference eNodeB,
and instructs all eNodeBs to adjust the time at the same time.
When the time on the eCoordinator approaches the time specified by the
AISSZONE.AdjustTimeparameter set in the ADD AISSZONE command, the eCoordinator
delivers eNodeBs the AISS_TIME_ADJUST_REQ messages including the IE AISS Time
Adjust, instructing each eNodeB to adjust the time and maintain time synchronization withthe reference eNodeB, as shown in Figure 3-10.
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NOTE
If the clock state is abnormal during time difference measurements, time difference measurements stop
even if the clock state restores to normal, and subsequent time difference adjustment cannot be
performed.
Figure 3-10Adjusting time differences
3.3 Synchronization Tracing
To maintain the time synchronization accuracy of Uu-based soft synchronization, eNodeBs
perform periodic fine-tuning on time differences between eNodeBs after initial
synchronization. Procedures for synchronization tracing include the collection of time
differences between each pair of eNodeBs and the adjustment of the time for non-referenceeNodeBs based on the time of the reference eNodeB.
3.4 Synchronization Maintenance
The synchronous Ethernet clock must be configured before Uu-based soft synchronization is
enabled so that frequency synchronization provided by the synchronous Ethernet clock serves
as the basis for time synchronization. Highly reliable and high-precision frequency
synchronization provided by synchronous Ethernet maintains time synchronization accuracy
during synchronization tracing.
The eNodeB-level parameter AISS.FLAGset in the SET AISS command specifies whetherto enable Uu-based soft synchronization on an eNodeB. The synchronous Ethernet clock can
be configured on an eNodeB by running the ADD SYNCETHcommand. The working mode
of the reference clock source and the clock synchronization mode of an eNodeB can be set by
running commands SET CLKMODEand SET CLKSYNCMODE, respectively.
eNodeBs report synchronization status to the eCoordinator, and the eCoordinator performs
different operations based on different synchronization status. Synchronization status
reporting involves three procedures: starting AISS synchronization status reports, sending
AISS synchronization status reports, and stopping AISS synchronization status reports.
1. During the starting of AISS synchronization status reports shown in Figure 3-11, the
eCoordinator sends eNodeBs the AISS_STATE_START_REQ messages, and then eacheNodeB sends the eCoordinator an AISS_STATE_START_RSP message.
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Figure 3-11Starting AISS synchronization status reports
2. During the sending of AISS synchronization status reports shown in Figure 3-12, each
eNodeB sends the eCoordinator an AISS_ STATE_RTP message including the IE Aiss
State that indicates the synchronization status. This message indicates whether the
frequency synchronization or time synchronization of the eNodeB is in the normal state.
Figure 3-12Sending AISS synchronization status reports
3. During the stopping of AISS synchronization status reports shown in Figure 3-13, the
eCoordinator sends an AISS_STATE_STOP_REQ message to the eNodeB that has sent
synchronization status reports, and then the eNodeB sends an AISS_STATE_STOP_RSP
message to the eCoordinator.
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Figure 3-13Stopping AISS synchronization status reports
3.5 Absolute Time Synchronization for eMBMS
eMBMS requires eNodeBs in a synchronization zone to achieve absolute time
synchronization with the Broadcast/Multicast Service Center (BM-SC), that is, the eNodeBs
must achieve time synchronization with the UTC time. UTC is short for Universal Time
Coordinated. However, Uu-based soft synchronization supports only the synchronization
between frame phases delivered by eNodeBs and frame numbers delivered by eNodeBs over
the Uu interfaces, and does not support time synchronization between eNodeBs and the UTC
time. The GPS (or IEEE1588 V2 clock) and Network Time Protocol (NTP) must be used to
achieve absolute time synchronization between eNodeBs within the synchronization zone and
the BM-SC.
NTP supports timing between eNodeBs and the U2000 in network operation and maintenance
(O&M). For details, see Time Management Feature Parameter Description. Both GPS (or
IEEE1588 V2 clock) and NTP support synchronization with the UTC time. However, the
NTP time is of lower precision and differs from the GPS time (or IEEE1588 V2 clock), which
requires time calibration.
The procedure for absolute time synchronization for eMBMS is as follows:
1. An eNodeB within the synchronization zone with the GPS (or IEEE1588 V2 clock)
installed is termed as the GPS eNodeB. The GPS eNodeB achieves time synchronization
with the UTC time obtained by the GPS (or IEEE1588 V2 clock).
2. eNodeBs within the synchronization zone with the NTP servers installed is termed as theNTP eNodeBs. The NTP eNodeBs achieve time synchronization with the NTP-obtained
UTC time. Compared with the GPS-obtained UTC time, the NTP-obtained UTC time
has the time difference T1.
3. Uu-based soft synchronization is enabled on eNodeBs within the synchronization zone.
Frame phases and frame numbers delivered by the GPS eNodeB and frame phases and
frame numbers delivered by the NTP eNodeBs are synchronized, respectively.
4. The GPS eNodeB calculates the time difference T1 and calibrates the time difference,
maintaining time synchronization between the NTP-obtained UTC time and the GPS-
obtained UTC time.
The methods for configuring the GPS, IEEE1588 V2 clock, and NTP are as follows:
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l GPS: Install the GPS on an eNodeB by running the ADD GPScommand. Set the
working mode of the reference clock source and the clock synchronization mode of the
eNodeB by running commands SET CLKMODEand SET CLKSYNCMODE,
respectively.
lIEEE1588 V2: Install the IEEE1588 V2 clock on an eNodeB by running the ADDIPCLKLINKcommand. Set the working mode of the reference clock source and the
clock synchronization mode of the eNodeB by running commands SET CLKMODE
and SET CLKSYNCMODE, respectively.
l NTP: Set the reference clock source to NTP by running theSET TIMESRCcommand.
Set the IP address, port number, timing period, and encryption mode of the NTP server
by running the ADD NTPCcommand. Set parameters related to the primary NTP server
by running the SET MASTERNTPScommand.
NOTE
l Set the SYNCCYCLEparameter in the ADD NTPCcommand to a value less than 60 minutes
to decrease the time differences between eNodeBs.
l The difference between the NTP time and the UTC time must be less than 4 seconds.
l The reference clock source of the synchronous Ethernet must be GPS.
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4Related FeaturesPrerequisite features
LOFD-00301301 Synchronization with Ethernet (ITU-T G.8261)
The Uu-based soft synchronization accuracy is dependent on synchronization reliability of the
synchronous Ethernet.
Mutually exclusive features
LOFD-080216 Uu based Soft Synchronization cannot be enabled if any of the following
features that are exclusive to LOFD-00301301 Synchronization with Ethernet (ITU-T G.
8261) is enabled:
l LBFD-00300504 Synchronization with BITSl LBFD-00300505 Synchronization with 1PPS
l LBFD-00300506 Synchronization with E1/T1
l LOFD-00301302 IEEE1588 V2 Clock Synchronization
l LOFD-00301303 Clock over IP (Huawei proprietary)
LOFD-080216 Uu based Soft Synchronization cannot be enabled if any of following features
that do not support the frame format on the PRACH is enabled:
l LOFD-001007 High Speed Mobility
l LOFD-001008 Ultra High Speed Mobility
l LOFD-001031 Extended CP
l LOFD-001009 Extended Cell Access Radius
The following features apply to multi-RRU cells and cannot work together with the Uu based
Soft Synchronization feature.
l LOFD-003029 SFN
l LOFD-070205 Adaptive SFN/SDMA
Impacted features
LOFD-080216 Uu based Soft Synchronization supports time synchronization for thefollowing features:
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LOFD-070220 eMBMS Phase 1 based on Centralized MCE Architecture
l LOFD-07022001 Multi-cell transmission in MBSFN area
l LOFD-07022002 Mixed transmission of unicast and broadcast
l LOFD-07022003 Data synchronization
l LOFD-07022004 Session admission control
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5Network ImpactSystem Capacity
No impact.
Network Performance
If the time differences between eNodeBs in eNodeB pairs are large during initial
synchronization, the time adjustment step is also large. As a result, services are interrupted for
several seconds during initial synchronization. Because initial synchronization is performed
once only after LOFD-080216 Uu based Soft Synchronization is enabled and performed when
traffic is light (for example, 02:00 in the morning), initial synchronization generally has little
impact on services. Synchronization tracing has no impact on services.
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6Engineering Guidelines
6.1 When to Use LOFD-080216 Uu based SoftSynchronization
Enable LOFD-080216 Uu based Soft Synchronization when all of the following conditions
are met:
l Related coordination features (listed in 4 Related Features) need to be deployed and
these features require eNodeBs to support time synchronization.
l Transmission devices support the synchronous Ethernet clock.
l Compared with LBFD-00300503 GPS Synchronization and LOFD-00301302 IEEE1588
V2 Clock Synchronization, operators want to deploy time synchronization at low cost
without the need for transmission network reconstruction.
6.2 Required Information
1. Determine the synchronization zone: Determine an area for deploying coordination
features (such as eMBMS and TDM eICIC) before enabling these features. This area is
called the synchronization zone.
2. Analyze traffic volume in the synchronization zone: Analyze the distribution of average
traffic volume in a week in different time spans within the synchronization zone.
Determine the time to collect time differences between eNodeBs in eNodeB pairs andthe time to adjust eNodeB time. Set the time to collect time difference to the time when
the traffic volume is neither too large nor too small. Because event A3 measurements are
required in time difference measurements and it takes 100 ms to perform preamble blind
detection in each event A3 measurement, the time to collect time differences cannot be
set to the peak traffic volume time to decrease impacts on services. In addition, time
difference measurements cannot be performed if the number of UEs in inter-eNodeB
handovers is too small. Therefore, the time to collect time differences cannot be set to
the time when the traffic volume is too small. You are advised to set the time to adjust
eNodeB time to the time when the traffic volume is light (for example, 02:00 in the
morning) in order to decrease impacts on services.
3. Analyze the stability of synchronization maintenance in synchronous Ethernet: Onlytime difference collection is activated in the synchronization zone, and time difference
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adjustment is not activated. Set the AISSZONE.MeasurePeriodparameter to 10in the
unit of day to check the stability of synchronization maintenance between eNodeB and
the fluctuation of time differences between eNodeBs in 10 days. The change of time
differences between more than 99% of eNodeBs must be less than 3 s.
4. Collect alarms reported by eNodeBs. First clear the following alarms if any is reported: ALM-25880 Ethernet Link Fault: This alarm indicates the frequency of
transmission link interruption in a single eNodeB and can be cleared by
troubleshooting transmission link faults.
ALM-26262 External Clock Reference Problem: This alarm indicates the frequency
that the reference clock source of a single eNodeB is unlocked and can be cleared
by troubleshooting clock link faults.
ALM-25621 Power Supply DC Output Out of Range, ALM-25622 Mains Input Out
of Range, and ALM-25626 Power Module Abnormal: These alarms indicate the
frequency that a single eNodeB is powered off and can be cleared by
troubleshooting power module faults.
(Optional) ALM-26266 Time Synchronization Failure: This alarm is reported only
when the NTP server is installed and indicates that a single eNodeB fails NTP
timing. This alarm can be cleared by troubleshooting NTP clock link faults.
6.3 Planning
6.3.1 RF Planning
This feature supports the deployment of Huawei eNodeBs providing consecutive intra-
frequency coverage and does not support mixed deployment of Huawei eNodeBs and non-Huawei eNodeBs.
6.3.2 Network Planning
l The eCoordinator is functioning normally. The Se interfaces between the eCoordinator
and eNodeBs are correctly configured and the Se links are in the normal state.
NOTE
For detailed descriptions of the Se interface, seeIP Transmission Feature Parameter Description.
For details about how to configure the Se interface, seeIP eRAN Engineering Guide Feature
Parameter Description.
l All eNodeBs within a synchronization zone must be configured with the same
synchronous Ethernet clock source and all transport devices within the synchronization
zone support synchronous Ethernet.
l Transmission devices must support the synchronization status message (SSM) protocol
defined by ITU-T G.8264.
l The synchronization accuracy of the clock in the upper level of the synchronous Ethernet
installed on eNodeBs must be less than or equal to 16 ppb.
l Distances between eNodeBs within a synchronization zone must be less than 15 km.
l The NTP server and GPS must be installed on eNodeBs when eMBMS is required. In
this case, the GPS must be selected as the synchronous Ethernet clock source.
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6.3.3 Hardware Planning
l ECO6910 is required.
l eNodeBs in any of the following types:
3900 series eNodeBs with the baseband processing unit being LBBPd or UBBP and themain control board being LMPT or UMPT.
NOTE
If a 3900 series eNodeB is equipped with the LBBPd and serves 4R and 8R cells, the PRACH
configurations of one cell cannot overlap with the PRACH configurations of another cell in the
time domain. This requires that the eNodeB level parameter PrachTimeStagSwitch be set to
ON(On)and cell-level parameter PrachConfigIndexCfgInd be set to NOT_CFG(Not
configure).
l The NTP server and GPS must be installed on eNodeBs when eMBMS is required. In
this case, the GPS must be selected as the synchronous Ethernet clock source.
6.4 Feature Deployment
6.4.1 Process
Step 1 Deploy the eCoordinator. The Se interfaces between the eCoordinator and eNodeBs arecorrectly configured and the Se links are in the normal state.
NOTE
For detailed descriptions of the Se interface, seeIP Transmission Feature Parameter Description. For
details about how to configure the Se interface, seeIP eRAN Engineering Guide Feature Parameter
Description.
Step 2 Enable Uu-based soft synchronization on eNodeBs, configure synchronous Ethernet clock forthe eNodeBs, and configure information about longitudes and latitudes of the eNodeBs.
Step 3 Configure X2 interfaces between eNodeBs.
Step 4 On the eCoordinator, configure a synchronization zone, add eNodeBs to the synchronizationzone, and configure a reference eNodeB.
Step 5 (Applied only to eMBMS) Install GPS (or IEEE1588 V2 clock) on one of the eNodeBs in thesynchronization zone, and then install NTP servers on all eNodeBs in the synchronization
zone. Synchronize the NTP time on all eNodeBs with the time on the eNodeB with GPS
installed.
Step 6 Activate the synchronization zone on the eCoordinator and activate the automatic eNodeBpairing calculation function.
----End
6.4.2 Requirements
Other Features
The prerequisite features of LOFD-080216 Uu based Soft Synchronization must be enabled
before this feature is enabled. For details, about the prerequisite features, see 4 RelatedFeatures.
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Hardware
For details, see 6.3.3 Hardware Planning.
LicenseFeature ID Feature
NameModel License
Control ItemNE Sales Unit
LOFD-080216 Uu based Soft
Synchronizati
on
LEC2AI
SS01
Uu based Soft
Synchronization(
LTE FDD) (per
eNodeB)
eCoordin
ator
per
eNodeBs
6.4.3 Data PreparationThe following table lists parameters related to eNodeB configurations.
The following table lists parameters related to synchronous Ethernet configuration.
Parameter Name Parameter ID Setting Notes Data Source
Link No. SYNCETH.LN Set this parameter to
0.
Network plan
(negotiation not
required)
Port No. SYNCETH.PN This parameter
specifies the numberof the port where the
synchronous-
Ethernet clock link
is configured. Set
this port and the
synchronous
Ethernet clock
source in the same
network.
Network plan
(negotiation notrequired)
SSM Selection SYNCETH.SSM Set this parameter to
the same value asthe setting on the
Ethernet clock
server.
Network plan
(negotiation notrequired)
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Parameter Name Parameter ID Setting Notes Data Source
Priority SYNCETH.PRI When two or more
clock sources are
used, a smaller value
of this parameter
specifies a higher
priority.
Set this parameter to
its default value
when the
synchronous
Ethernet is the only
clock source.
Network plan
(negotiation not
required)
Clock Working
Mode
CLKMODE.MOD
E
It is recommended
that this parameterbe set to
MANUAL(Manual
).
Network plan
(negotiation notrequired)
Selected Clock
Source
CLKMODE.CLKS
RC
Set this parameter to
SYNCETH(SyncEt
h Clock).
Network plan
(negotiation not
required)
Clock Source No. CLKMODE.SRCN
O
Set this parameter to
the same value as
the established clock
link number.
Network plan
(negotiation not
required)
Clock
Synchronization
Mode
CLKSYNCMODE.
CLKSYNCMODE
The clock source
supports only
frequency
synchronization.
Therefore, set this
parameter to
FREQ(FREQ).
Network plan
(negotiation not
required)
The following table lists parameters related to the configuration of longitudes and latitudes of
eNodeBs.
Parameter Name Parameter ID Setting Notes Data Source
Location Name LOCATION.LOCA
TIONNAME
This parameter
specifies the
location name of the
eNodeB.
Network plan
(negotiation not
required)
Geo-coordinate Data
Format
LOCATION.GCDF This parameter
specifies the format
of geographical
coordinates.
Network plan
(negotiation not
required)
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Parameter Name Parameter ID Setting Notes Data Source
Altitude LOCATION.LATI
TUDEDEGFORM
AT
This parameter
specifies the altitude
of the eNodeB. A
negative value
indicates the south
latitude and a
positive value
indicates the north
latitude.
Network plan
(negotiation not
required)
Longitude LOCATION.LONG
ITUDEDEGFORM
AT
Indicates the
longitude of the base
station. A negative
value indicates the
west longitude and a
positive value
indicates the east
longitude.
Network plan
(negotiation not
required)
(Applied only to eMBMS) The following table lists parameters related to the configuration of
GPS and the NTP server.
Parameter Name Parameter ID Setting Notes Data Source
GPS Clock No. GPS.GN This parameter
indicates the number
of the GPS clock
link.
Radio network plan
(internal planning)
GPS Work Mode GPS.MODE This parameter
specifies the
working mode of the
satellite card. Set
this parameter to
GPS(GPS). If the
eMBMS feature is
required, the
reference eNodeB
must have GPS
installed.
Radio network plan
(internal planning)
Time Source TIMESRC.TIMES
RC
This parameter
specifies the
external reference
time source of the
NE.
Radio network plan
(internal planning)
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Parameter Name Parameter ID Setting Notes Data Source
IPv4 Address of
NTP Server
NTPCP.IP This parameter
specifies the IPv4
address of the NTP
server.
Radio network plan
(internal planning)
Port Number NTPCP.PORT This parameter
specifies the port
number of the NTP
server. An NTP
client performs time
calibration with the
NTP server through
the port specified by
this parameter.
Radio network plan
(internal planning)
AuthenticationMode
NTPCP.AUTHMODE
This parameterspecifies the
encryption mode. If
this parameter is set
to PLAIN, data is
transmitted in
plaintext.
Radio network plan(internal planning)
The following table lists parameters used to control whether to enable Uu-based soft
synchronization.
Parameter Name Parameter ID Setting Notes Data Source
Uu Interface Soft
Synchronization
Switch
AISS.FLAG Set this parameter to
ON(On).
Radio network plan
(internal planning)
Soft-synchronized
Network Adaptive
Mode
AISS.NETMODE This parameter
specifies the
adaptive mode of the
soft synchronous
transport network. If
the network jitter islarge, set this
parameter to
ENH(Enhanced
Mode). Otherwise,
set this parameter to
GEN(General
Mode). This
parameter does not
apply to eGBTS.
Radio network plan
(internal planning)
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Parameter Name Parameter ID Setting Notes Data Source
Uu Soft Syn Phase
Adjustment Period
AISS.FREQUENC
E
This parameter
specifies the
adjustment period of
the frame clock
phase when the Uu
interface soft
synchronization
Phase Lock function
is enabled on the
eNodeB.
This parameter is
negotiated with the
peer end.
The following tables list parameters that must be configured on the eCoordinator side related
to synchronization zone configuration, eNodeB addition, and eNodeB pair configuration.
The following table lists parameters related to synchronization zone configuration.
Parameter Name Parameter ID Setting Notes Data Source
Synchronization
Zone ID
AISSZONE.AISSZ
oneId
This parameter
specifies the unique
ID of a Uu-based
soft synchronization
zone.
Network plan
(negotiation not
required)
Time Adjust Period AISSZONE.Adjust
Period
This parameter
specifies the cycle inwhich the eNodeB
time is adjusted.
Network plan
(negotiation notrequired)
Time Measure
Period
AISSZONE.Measu
rePeriod
This parameter
specifies the cycle in
which the eNodeB
time is measured.
The time is
measured per cycle.
Network plan
(negotiation not
required)
Adjust Threshold AISSZONE.Adjust
Threshold
This parameter
specifies thethreshold for
adjusting the
eNodeB time. The
eNodeB time is not
adjusted when the
time difference is
less than this
threshold.
Network plan
(negotiation notrequired)
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Parameter Name Parameter ID Setting Notes Data Source
Start Time for
Measurement
AISSZONE.Measu
reTime
This parameter
specifies the start
time for measuring
time difference
between eNodeBs in
a Uu-based soft
synchronization
zone.
Network plan
(negotiation not
required)
Adjust Time AISSZONE.Adjust
Time
This parameter
specifies the
scheduled timing for
adjusting the time of
an eNodeB in the
Uu-based soft
synchronization
zone.
Network plan
(negotiation not
required)
Frequency Band AISSZONE.Freque
ncyBand
This parameter
specifies the
frequency band on
which a cell in the
Uu-based soft
synchronization
zone works. For
details about this
parameter, see 3GPP
TS 36.104. For cellsin the Uu-based soft
synchronization
zone, the frequency
band and downlink
EARFCN
configuration must
meet the relationship
specified in 3GPP
TS 36.104.
Network plan
(negotiation not
required)
Downlink EARFCN AISSZONE.DLFre
quency
This parameter
specifies thedownlink EARFCN
for a cell in the Uu-
based soft
synchronization
zone. For details
about this parameter,
see 3GPP TS
36.104.
Network plan
(negotiation notrequired)
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Parameter Name Parameter ID Setting Notes Data Source
Downlink
Bandwidth
AISSZONE.DLBan
dWidth
The parameter
specifies the
downlink bandwidth
of a cell. The
downlink bandwidth
is denoted by
number of RBs. If
this parameter is set
to CELL_BW_N25,
25 RBs are allocated
in the downlink. If
this parameter is set
to CELL_BW_N50,
50 RBs are allocated
in the downlink. Fordetails about this
parameter, see 3GPP
TS 36.104.
Network plan
(negotiation not
required)
RSRP Threshold AISSZONE.RSRPT
hreshold
This parameter
specifies the
minimum RSRP of a
cell that a UE can
select after
measurements. A
larger value of this
parameter results inbetter signal quality
of the area in the cell
in which the UE
locates and better
random access
performance.
Network plan
(negotiation not
required)
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Parameter Name Parameter ID Setting Notes Data Source
A3 Offset for Soft
Synchronization
AISSZONE.A3Off This parameter
specifies the offset
used to trigger event
A3. The event A3
itself is reported by
UEs which measure
the time difference
on the edge of
neighboring cells.
For details about this
parameter, see 3GPP
TS 36.331. A larger
value of this
parameter results in
fewer UEs reportingevent A3 and a
lower probability of
CEUs being selected
for time difference
measurements. A
smaller value of this
parameter results in
a longer distance
between the UE and
the neighboring cell,
and a lower
probability thatpreambles sent by
the UE are being
blindly detected by
the neighboring cell.
Network plan
(negotiation not
required)
CEU Punish Time AISSZONE.Punish
Time
This parameter
specifies the interval
at which a CEU
cannot perform a
time difference
measurement after
the previousmeasurement ends.
A parameter either
too large or too
small in value has
negative impacts on
the time difference
measurements of
CEUs.
Network plan
(negotiation not
required)
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Parameter Name Parameter ID Setting Notes Data Source
Blind Detection
Duration
AISSZONE.Detect
LastTime
This parameter
specifies the
duration for blind
preamble detection
on a neighboring
eNodeB. A larger
value of this
parameter requires
higher baseband
processing
capability. A
parameter of a
smaller value
decreases the
success rate of blinddetection.
Network plan
(negotiation not
required)
Leap Second
Adjustment Value
AISSZONE.LEAPS
ECOND
This parameter
specifies the leap
second value of the
Coordinated
Universal Time
(UTC). The NTP
time is derived from
UTC, which
deviates from the
GPS time in thelevel of leap
seconds. Therefore,
the eNodeB must
consider the leap
second deviation
when converting the
NTP time to the
GPS time. IfNTPis
configured, set this
parameter to a valid
value. Otherwise, set
this parameter to aninvalid value 0.
Radio network plan
(internal planning)
The following table lists parameters used to add eNodeBs into the synchronization zone.
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Parameter Name Parameter ID Setting Notes Data Source
Base Station MCC ENBAISS.BaseStati
onMCC
This parameter
specifies the mobile
country code (MCC)
of a base station in a
Uu-based soft
synchronization
zone.
Network plan
(negotiation not
required)
Base Station MNC ENBAISS.BaseStati
onMNC
This parameter
specifies the mobile
network code
(MNC) of a base
station in a Uu-
based soft
synchronization
zone.
Network plan
(negotiation not
required)
Base Station ID ENBAISS.BaseStati
onId
This parameter
specifies the ID of a
base station in a Uu-
based soft
synchronization
zone.
Network plan
(negotiation not
required)
LPN Or Not ENBAISS.IsLPN This parameter
specifies whether an
eNodeB is a lower
power node (LPN).
Network plan
(negotiation not
required)
Base Station Type ENBAISS.BaseStati
onType
This parameter
specifies the
eNodeB type.
Network plan
(negotiation not
required)
The following table lists parameters related to the configuration of eNodeB pairs.
Parameter Name Parameter ID Setting Notes Data Source
MCC of BaseStation 1
AISSNENB.BaseStation1MCC
This parameterspecifies the MCC
of base station 1.
Network plan(negotiation not
required)
MNC of Base
Station 1
AISSNENB.BaseSt
ation1MNC
This parameter
specifies the MNC
of base station 1.
Network plan
(negotiation not
required)
MCC of Base
Station 2
AISSNENB.BaseSt
ation2MCC
This parameter
specifies the MCC
of base station 2.
Network plan
(negotiation not
required)
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Parameter Name Parameter ID Setting Notes Data Source
MNC of Base
Station 2
AISSNENB.BaseSt
ation2MNC
This parameter
specifies the MNC
of base station 2.
Network plan
(negotiation not
required)
6.4.4 Precautions
l During manual configuration of LOFD-080216 Uu based Soft Synchronization in
scenarios with LOFD-001037 RAN Sharing with Dedicated Carrier or LOFD-070206
Hybrid RAN Sharing deployed, one eNodeB has several IDs specified by the
ENBAISS.BaseStationIdparameter. Only the ID of the primary operator is added when
the eNodeB is added into the synchronization zone.
l The longitudes and latitudes of eNodeBs must be configured first before the
eCoordinator automatically calculates eNodeB pairs by running the ACT
AISSNENBCALCcommand. If the attributes of an eNodeB pair are changed, run this
command again to activate an automatic eNodeB pairing calculation. The attribute
changes include changes of longitude and latitude of eNodeBs in the pair, addition and
removal of eNodeBs, X2 interfaces between eNodeBs, or cells under eNodeBs, and
neighbor relationship changes.
l In Uu-based soft synchronization, the signal strength is determined based on the
reference signal received power (RSRP) contained in event A3 reports. However, if the
TriggerQuantityparameter is set to RSRQand the ReportQuantityparameter is set to
SAME_AS_TRIG_QUANduring the execution of the MOD CELLMCPARA
command, the eNodeB does not report RSRP. Therefore, do not set the TriggerQuantity
parameter to RSRQor set the ReportQuantityparameter to SAME_AS_TRIG_QUANwhen Uu-based soft synchronization is required.
l Preamble blind detection cannot distinguish which preamble is used in Uu-based soft
synchronization. Therefore, do not use the preambles on the same root sequence with the
preamble for blind detection. Otherwise, exceptions will occur during preamble blind
detection. The following conditions must be met before enabling Uu-based soft
synchronization:
The radius of all cells must be greater than 5 km to ensure normal preamble
allocation.
The RachAdjSwitch(RachAdjSwitch) option of the
CellAlgoSwitch.RachAlgoSwitchparameter must be deselected.
l The time difference adjustment time must be later than the time difference measurement
time. If Uu-based soft synchronization is deployed for the first time and the time
difference adjustment time is earlier than the time difference measurement time, the time
difference cannot be adjusted until the second time difference adjustment time is reached
after the first time difference measurement. You are advised to enable Uu-based soft
synchronization at least one day earlier than the time specified by parameter settings.
6.4.5 Activation
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6.4.5.1 7.4.5.1 Using the CME to Perform Batch Configuration for NewlyDeployed eNodeBs
Enter the values of the parameters listed in Table 6-1in a summary data file, which also
contains other data for the new eNodeBs to be deployed.
Then, import the summary data file into the Configuration Management Express (CME) for
batch configuration. For detailed instructions, see "Creating eNodeBs in Batches" in the initial
configuration guide for the eNodeB, which is available in the eNodeB product documentation.
The summary data file may be a scenario-specific file provided by the CME or a customized
file, depending on the following conditions:
l The managed objects (MOs) in Table 6-1are contained in a scenario-specific summary
data file. In this situation, set the parameters in the MOs, and then verify and save the
file.
l Some MOs in Table 6-1are not contained in a scenario-specific summary data file. In
this situation, customize a summary data file to include the MOs before you can set the
parameters.
Table 6-1MOs that must be configured in Uu-based soft synchronization
MO Sheet in theSummary DataFile
Parameter Group Remarks
Tasm Common Data Um Interface Soft Synchronization
Switch, ClkSource Type, Clock
Synchronization Mode, Working
Mode, ClkSource No
-
SyncEth Common Data SyncEth Type, SyncethNo, SSM
Selection, Priority, Cabinet No,
Subrack No, Slot No, Port No
-
GPS Common Data GpsNo, Cabinet No, Subrack No, Slot
No, Work Mode, Priority
-
TIMESRC Common Data Time Source -
NtpCp Common Data NTP IP, NTP IP Mask, Port,
SyncCycle, Authentication Mode,
Authentication Key, Authentication
Key Index, MasterFlag
-
Location Base Station
Transport Data
LocationName, LatitudeDegFormat,
LongitudeDegFormat
-
6.4.5.2 Using the CME to Perform Batch Configuration for Existing eNodeBs
Batch reconfiguration using the CME is the recommended method to activate a feature on
existing eNodeBs. This method reconfigures all data, except neighbor relationships, formultiple eNodeBs in a single procedure. The procedure is as follows:
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Step 1 After creating a planned data area, choose CME> Advanced> Customize Summary DataFile(U2000 client mode), or choose Advanced> Customize Summary Data File(CME
client mode), to customize a summary data file for batch reconfiguration.
NOTE
For context-sensitive help on a current task in the client, press F1.
Step 2 Choose CME> LTE Application> Export Data> Export Base Station BulkConfiguration Data(U2000 client mode), or choose LTE Application> Export Data>
Export Base Station Bulk Configuration Data(CME client mode), to export the eNodeB
data stored on the CME into the customized summary data file.
Step 3 In the summary data file, set the parameters in the MOs listed in Table 6-1and close the file.
Step 4 Choose CME> LTE Application> Import Data> Import Base Station BulkConfiguration Data(U2000 client mode), or choose LTE Application> Import Data>
Import Base Station Bulk Configuration Data(CME client mode), to import the summary
data file into the CME, and then start the data verification.
Step 5 After data verification is complete, choose CME> Planned Area> Export IncrementalScripts(U2000 client mode), or choose Area Management> Planned Area> Export
Incremental Scripts(CME client mode), to export and activate the incremental scripts.
----End
6.4.5.3 Using the CME to Perform Single Configuration
On the CME, set the parameters listed in the 6.4.3 Data Preparationsection for a single
eNodeB. The procedure is as follows:
Step 1 In the planned data area, click Base Stationin the upper left corner of the configurationwindow.
Step 2 In area 1 shown in Figure 6-1, select the eNodeB to which the MOs belong.
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Figure 6-1MO search and configuration window
NOTE
l To view descriptions of the parameters in the MO, click in area 4 and press F1.
lArea 5 displays the details of a selected area-4 entry in vertical format. Click the Detailsicon toshow or hide this area.
Step 3 On the Searchtab page in area 2, enter an MO name, for example, CELL.
Step 4 In area 3, double-click the MO in the Object Namecolumn. All parameters in this MO aredisplayed in area 4.
Step 5 Set the parameters in area 4 or 5.
Step 6 Choose CME> Planned Area> Export Incremental Scripts(U2000 client mode), orchoose Area Management> Planned Area> Export Incremental Scripts(CME client
mode), to export and activate the incremental scripts.
----End
6.4.5.4 Using MML Commands
Step 1 Enable Uu-based soft synchronization on eNodeBs.
Run the SET AISScommand to enable Uu-based soft synchronization on eNodeBs.
Step 2 Configure synchronous Ethernet on eNodeBs.
Run the ADD SYNCETHcommand to add synchronous Ethernet links.
Run the SET CLKMODEcommand to set the reference clock source to the synchronousEthernet clock.
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Run the SET CLKSYNCMODEcommand to set the clock synchronization mode to
frequency synchronization.
Step 3 Configure eNodeBs' longitudes and latitudes on eNodeBs.
Run the ADD LOCATIONcommand on eNodeBs to configure longitudes and latitudes ofeNodeBs.
Step 4 Bind the eNodeB's location to the sector equipment.
Run the MOD SECTORcommand to bind the eNodeB's location to the sector equipment.
Step 5 Configure a synchronization zone using the eCoordinator.
Run the ADD AISSZONEcommand to configure a synchronization zone.
Step 6 Add eNodeBs to the synchronization zone using the eCoordinator.
Run the ADD ENBAISScommand to add eNodeBs to the synchronization zone.
Step 7 (Optional) Configure GPS or IEEE1588 V2 clock on one eNodeB (This eNodeB does notrequire synchronous Ethernet.)
Run the ADD GPScommand to add GPS, or run the ADD IPCLKLINKcommand to add
the IP clock link.
Run the SET CLKMODEcommand to set the reference clock source to GPS.
Run the SET CLKSYNCMODEcommand on eNodeBs to set the clock synchronization
mode to time synchronization.
Step 8 (Applied only to eMBMS) Configure NTP on all eNodeBs in the synchronization zone.
Run the SET TIMESRCcommand to set the reference clock source to NTP.
Run the ADD NTPCcommand to configure the IP address, port number, timing period, and
encryption mode of the NTP server. Run the SET MASTERNTPScommand to configure
parameters related to the master NTP server.
Step 9 Add eNodeB pairs on the eCoordinator. eNodeB pairs can be added either automatically ormanually. eNodeB pairs are automatically added by default and can be manually adjusted.
l Adding eNodeB pairs automatically for Uu-based soft synchronization
Run the ACT AISSZONEcommand to activate the synchronization zone.
Run the ACT AISSNENBCALCcommand to activate automatic eNodeB pairing
calculation.
l Adding eNodeB pairs manually for Uu-based soft synchronization
Run the ADD AISSNENBcommand to add eNodeBs into eNodeB pairs for
synchronization.
Run the ACT AISSZONEcommand to activate the synchronization zone.
----End
6.4.5.5 MML Command Examples
//Enabling Uu-based soft synchronization on eNodeBs
SET AISS: FLAG=ON, NETMODE=ENH, FREQUENCE=480SEC;
//Configuring synchronous Ethernet on eNodeBs
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ADD ETHPORT: SN=7, SBT=BASE_BOARD, PA=COPPER, SPEED=AUTO, DUPLEX=AUTO;
ADD SYNCETH: LN=0, SN=7, PN=0;
SET CLKMODE: MODE=MANUAL, CLKSRC=SYNCETH;
SET CLKSYNCMODE: CLKSYNCMODE=FREQ;
//Configuring eNodeBs' longitudes and latitudes on eNodeBs
ADD LOCATION: LOCATIONNAME="hangzhou_NODE_ONE", GCDF=Degree, LATITUDEDEGFORMAT=0,
LONGITUDEDEGFORMAT=0;
//Binding the eNodeB's location to the sector equipment
MOD SECTOR:SECTORID=0,LOCATIONNAME="han