1.2 m hz networking for bcch trxs(gbss21.1 draft a)

GSM BSS
1.2 MHz Networking for BCCH TRXs
Feature Parameter Description
Issue Draft A
Date 2018-12-30
HUAWEI TECHNOLOGIES CO., LTD.

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Issue Draft A (2018-12-30) Copyright © Huawei Technologies Co., Ltd. i

Contents
1 Change Description.......................................................................................................................1
1.1 GBSS21.1 Draft A (2018-12-30)....................................................................................................................................1
2 About This Document.................................................................................................................. 2
2.1 General Statements.........................................................................................................................................................2
2.2 Applicable RAT.............................................................................................................................................................. 2
3 Overview......................................................................................................................................... 3
4 1.2 MHz Networking for BCCH TRXs...................................................................................... 5
4.1 Principles........................................................................................................................................................................ 5
4.1.1 BTS Grouping and Timeslot Staggering..................................................................................................................... 5
4.1.2 Intelligent BCCH Timeslot Assignment......................................................................................................................7
4.2 Network Analysis........................................................................................................................................................... 8
4.2.1 Benefits........................................................................................................................................................................8
4.2.2 Impacts.........................................................................................................................................................................8
4.3 Requirements................................................................................................................................................................12
4.3.1 Licenses..................................................................................................................................................................... 13
4.3.2 Software.....................................................................................................................................................................13
4.3.3 Hardware................................................................................................................................................................... 15
4.3.4 Networking................................................................................................................................................................ 16
4.3.5 Others.........................................................................................................................................................................16
4.4 Operation and Maintenance..........................................................................................................................................16
4.4.1 When to Use 1.2 MHz Networking for BCCH TRXs...............................................................................................17
4.4.2 Data Configuration.................................................................................................................................................... 20
4.4.2.1 Data Preparation..................................................................................................................................................... 20
4.4.2.2 Using MML Commands.........................................................................................................................................22
4.4.2.3 Using the CME....................................................................................................................................................... 22
4.4.3 Activation Verification.............................................................................................................................................. 23
4.4.4 Network Monitoring..................................................................................................................................................23
5 Parameter.......................................................................................................................................24
6 Counters........................................................................................................................................ 25
7 Glossary.........................................................................................................................................26
GSM BSS
1.2 MHz Networking for BCCH TRXs Feature Parameter
Description Contents
Issue Draft A (2018-12-30) Copyright © Huawei Technologies Co., Ltd. ii

8 Reference Documents.................................................................................................................27
GSM BSS
Description Contents
Issue Draft A (2018-12-30) Copyright © Huawei Technologies Co., Ltd. iii

1Change Description
This section describes changes not included in the "Parameters", "Counters", "Glossary", and
"Reference Documents" chapters. These changes include:
l Technical changes
Changes in functions and their corresponding parameters
l Editorial changes
Improvements or revisions to the documentation
1.1 GBSS21.1 Draft A (2018-12-30)
This issue introduces the following changes to GBSS20.1 03 (2018-11-12).
Technical Changes
Change Description Parameter Change
Optimized the channel allocation function for the
BCCH TRX. For details, see the following sections:
l 4.1.2 Intelligent BCCH Timeslot Assignment
l 4.2.2 Impacts
l 4.4.2 Data Configuration
Added the following
parameters:
GCELLCHMGAD.BCCHTR
XTSAllocateOptSw
GCELLCHMGAD.BCCHTR
XIdleChnlNumber
Editorial Changes
Optimized the setting notes of the feature parameters. For details, see 4.4.2.1 Data
Preparation and 4.4.2.2 Using MML Commands.
GSM BSS
Description 1 Change Description
Issue Draft A (2018-12-30) Copyright © Huawei Technologies Co., Ltd. 1

2About This Document
This document describes the GBFD-200201 1.2 MHz Networking for BCCH TRXs feature,
including its technical principles, related features, network impact, and engineering
guidelines.
2.1 General Statements
Purpose
Feature Parameter Description documents are intended to acquaint readers with:
l The technical principles of features and their related parameters
l The scenarios where these features are used, the benefits they provide, and the impact
they have on networks and functions
l Requirements of the operating environment that must be met before feature activation
l Parameter configuration required for feature activation, verification of feature activation,
and monitoring of feature performance
NOTE
This document only provides guidance for feature activation. Feature deployment and feature
gains depend on the specifics of the network scenario where the feature is deployed. To achieve
the desired gains, contact Huawei professional service engineers.
Software Interfaces
Any parameters, alarms, counters, or managed objects (MOs) described in Feature Parameter
Description documents apply only to the corresponding software release. For future software
releases, refer to the corresponding updated product documentation.
2.2 Applicable RAT
This document applies to GSM.
GSM BSS
Description 2 About This Document

3Overview
Expansion of mobile services and increased spectrum refarming have been placing ever more
strain on GSM spectrum. Tighter BCCH frequency reuse patterns have been creating
additional interference on the BCCH TRX, and this interference affects user access for voice
services.
On traditional GSM networks, the BCCH frequency reuse pattern is 4x3. This feature is
developed for operators with insufficient spectrum resources and helps them achieve 2x3
BCCH frequency reuse on the basis of Um-interface synchronization. After the BCCH
frequency reuse is changed from 4x3 to 2x3, the BCCH frequency bandwidth decreases from
2.4 MHz to 1.2 MHz, the reuse distance is shortened, and the uplink and downlink
interference increases significantly, as shown in Figure 3-1.
Figure 3-1 1.2 MHz Networking for BCCH TRXs
However, this feature and its prerequisite features use the interference suppression techniques
listed below to improve BCCH TRX performance. When these techniques are used, a 2x3
reuse pattern can deliver nearly the same signal quality as 4x3.
GSM BSS
Description 3 Overview

l Uplink interference suppression: The channels with the least interference are scheduled
for uplink transmission, and an interference cancellation combining (ICC) algorithm is
applied based on interference detection and estimation. Besides, this technology helps
eliminate interference using the interference cancellation combining (ICC) algorithm
based on interference detection and estimation.
l Downlink interference suppression: BCCH timeslots are staggered such that the
downlink transmit power of timeslot 0 on the BCCH TRX is reduced to increase the
immediate assignment success rate. If the downlink receive quality becomes poor, this
technique helps reduce the downlink transmit power of the interference source and boost
the transmit power of desired signals. This process increases the downlink carrier-to-
interference ratio. For AMR services, this technique reduces the downlink transmit
power without decreasing the voice encoding rate. This way, network interference is
lowered and network performance is improved.
This feature divides BTSs into groups A and B on a synchronous network. Timeslots of
BCCH TRXs in each group have a difference of four timeslots. In addition, this feature uses
specific channel allocation algorithms to improve uplink and downlink performance.
GSM BSS
Description 3 Overview

41.2 MHz Networking for BCCH TRXs
4.1 Principles
4.1.1 BTS Grouping and Timeslot Staggering
This feature divides BTSs into two groups (A and B) based on Um-interface synchronization.
In the following example, the BCCH TRXs use the 2x3 frequency reuse pattern, as shown in
Figure 4-1.
GSM BSS
Description 4 1.2 MHz Networking for BCCH TRXs

Figure 4-1 BTS grouping – groups A and B
The BCCH TRXs of cells in groups A and B are synchronized such that they have a
difference of four timeslots. Specifically, timeslots 0 and 4 of group-A cells are aligned
respectively with timeslots 4 and 0 of group-B cells. This feature decreases the transmit power
of timeslots 4 on the downlink to improve downlink performance of timeslots 0 of the BCCH
TRX, improving the service access success rate.
You can set the BTS.TSOFFSETGRP parameter to divide BTSs into groups A and B.
Timeslot offsets are respectively set to 0 and 4 for group A (BTS.TSOFFSETGRP is set to
GroupA) and group B (BTS.TSOFFSETGRP is set to GroupB). There is a difference of
four timeslots between groups A and B. Timeslot 0 of group A is aligned with timeslot 4 of
group B, and timeslot 0 of group B is aligned with timeslot 4 of group A, as shown in Figure
4-2.
Figure 4-2 Timeslot alignment
GSM BSS

NOTE
If attributes of groups A and B are modified (for example, the value of BTS.TSOFFSETGRP is
changed from NoGroup or GroupA to GroupB, or changed from GroupB to NoGroup or GroupA),
call drops will occur. It is recommended that you modify group attributes when traffic is light.
4.1.2 Intelligent BCCH Timeslot Assignment
This function optimizes channel allocation for the BCCH TRX, improving spectral efficiency
and network quality.
When GCELLCHMGAD.BCCHTRXTSIntlAllocateSw is set to ON, this function is
enabled. Channel priorities are allocated to groups A and B based on rules illustrated in
Figure 4-3, in an attempt to ensure timeslot 4 aligned with timeslot 0 of the BCCH TRX is
idle. This function can be used with the IBIS feature to improve the downlink BCCH TRX
performance.
Figure 4-3 Channel group priorities
Timeslot 4 is allocated the lowest priority and its downlink transmit power can be reduced to
improve BCCH performance. You can set the GCELLCHMGAD.BCCHTS4PwrDecrThld
parameter to adjust timeslot 4 transmit power decreases.
NOTE
Timeslot 4 is allowed to carry calls only with a high receive level after timeslot 4 transmit power is
decreased. Calls with downlink receive level lower than the value of
GCELLCHMGAD.ChAllcSoftBlockCallLevThld are not allocated timeslot 4 of the BCCH TRX. In
this case, the value of S3019B:Number of Level-caused Soft Blocks During BCCH TRX Channel
Allocation is increased by 1.
When GCELLCHMGAD.BCCHTRXPrefAllocateTCHHSw is set to ON, the BSC
preferentially allocates TCH/Hs to BCCH TRXs.
The GCELLCHMGAD.ChAllcSoftBlockCapThld parameter is used to control traffic
carried by the BCCH TRX. If the BCCH TRX channel seizure ratio is greater than or equal to
the value of GCELLCHMGAD.ChAllcSoftBlockCapThld, the BSC performs soft block on
newly accessed calls. In this case, the value of S3019A:Number of Capacity-caused Soft
Blocks During BCCH TRX Channel Allocation is increased by 1.
When the GCELLCHMGAD.ChanGroupAdjustSw parameter is set to ON, the BSC
periodically triggers intra-cell inter-channel group handovers from a low-priority channel
group to a high-priority channel group to reduce interference created on the same timeslot of
different groups. When GCELLCHMGAD.ChanGroupAdjustOptSw is set to ON(On):
l In concentric cell scenarios, a call can be handed over only to a higher-priority channel
group in an equivalent-level subcell. Specifically, a call of an underlaid subcell and a call
GSM BSS

of an overlaid subcell can be respectively handed over only to a higher-priority channel
group in an underlaid and an overlaid subcell. Handovers between underlaid and overlaid
subcells are controlled by the underlaid and overlaid subcell handover algorithm. For
details, see Concentric Cell Feature Parameter Description.
l The BSC needs to determine MS-supported frequency bands before inter-channel group
handovers are triggered, because this function applies only to channel groups
corresponding to these frequency bands.
l For a call on which intra-cell handovers are performed due to poor signal quality, inter-
channel group handovers cannot be triggered for the call before it is released, preventing
ping-pong handovers.
Users can specify the priority policy of non-BCCH TRX channels using the
GCELLCHMGAD.NonBCCHTRXChAllcPriPolicy parameter to control priorities of non-
BCCH and BCCH TRX channels.
When GCELLCHMGAD.NonBCCHTRXChAllcPriPolicy is set to STRATEGY1, the
channel group priorities shown in Figure 4-3 are used. Setting the priority policy for TCH
TRX channel allocation increases the probability that the interfering timeslot of the BCCH
TRX is in the idle state, improving gains delivered by IBIS and the interference source-based
precise power control function in the User-level Precise Power Control feature.
GCELLCHMGAD.BCCHTRXInterfOptPolicy specifies the BCCH TRX interference
optimization policy. When this parameter is set to STRATEGY1, the downlink power
decrease of frames on the BCCH TRX where IBIS takes effect is the common power control
value and does not exceed 3 dB. When this parameter is set to STRATEGY2, the BSC does
not optimize interference in downlink transmit signals of the BCCH TRX.
For cells experiencing congestion, set GCELLCHMGAD.ChAllcSoftBlockCapThld to 100
and set GCELLCHMGAD.BCCHTRXTSAllocateOptSw to ON(on) to enable the optimized
timeslot allocation function for the BCCH TRX. If the number of idle TCHs on the BCCH
TRX is less than or equal to the value of GCELLCHMGAD.BCCHTRXIdleChnlNumber,
the BSC preferentially allocates timeslot 4 to the calls with a downlink receive level of greater
than or equal to the value of GCELLCHMGAD.ChAllcSoftBlockCallLevThld. This helps
prevent call drops caused by allocation of timeslot 4 to calls with low levels.
4.2 Network Analysis
4.2.1 Benefits
This feature improves BCCH spectral efficiency by 50%. It reduces the GSM BCCH
frequency bandwidth from the traditional 2.4 MHz to 1.2 MHz, and the increased spectral
efficiency means that less money is spent on spectrum resources and network value is
maximized.
In GU/GL refarming and GU@5MHz scenarios, this feature frees up spectrum resources for
customers to deploy UMTS or LTE networks, improving user experience.
4.2.2 Impacts
Network Impacts
l System capacity
GSM BSS

BCCH TRX capacity is the same as that of the 2.4 MHz networking for BCCH TRXs.
l Network performance
The impact of this solution on network performance varies with network scenarios
before solution deployment. The following table describes the network performance
impact (based on the evaluation baseline) in S111@1.2 MHz networking in comparison
with that in S111@2.4 MHz networking when this feature is used.
Table 4-1 Network performance impacts in S111@1.2 MHz networking in comparison
with that in S111@2.4 MHz networking
Item Evaluation
Baseline
Impact on Network Performance
MOS About 3.2 points 0.1 to 0.3 points lower
ZTR304A: Call Drop
Rate on TCH per
cell(Excluding
Handover)
About 1% 0.2% to 0.3% higher
HQI Uplink HQI (0 to
5) of about 98%
0.3% to 0.6% lower
Downlink HQI
(0~5) of about
98%
0.6% to 0.9% lower
RH303A: Success
Rate of Radio
Handover
About 98% 0.6% to 1.2% lower
AR9780: Average
CPU Usage of the
XPU
Load before
deployment
l The interference source-based
precise power control function for
SDCCH is disabled: increased by
up to 3%
l The interference source-based
precise power control function for
SDCCH is enabled: increased by up
to 5%
GSM BSS

l Worse KPIs of the original network lead to poorer network performance. Better KPIs
of the original network lead to better network performance. The preceding network
performance impact is evaluated based on the evaluation baseline. The KPIs of most
sites on the live network are better than the baseline. Therefore, the actual network
impact is less than the network impact described in this table and must be evaluated
based on live-network conditions.
l In-depth network optimization improves network performance to an extent that KPIs
in S111@1.2 MHz networking are virtually the same in S111@2.4 MHz networking
(the call drop rate changes within 0.1%).
l This feature depends on inter-BTS time synchronization. A synchronization failure
between BTSs as a result of GPS antenna faults, transmission faults, and BTS
restarting causes the KPIs to further deteriorate from the values listed in the above
table. When the Soft-Synchronized Network feature is also enabled, a
synchronization failure between BTSs requires a longer time for the BTSs to restore
the synchronization state, having a greater impact on network performance. It is
likely that the immediate assignment success rate further decreases by 0.4% to 0.6%,
the call drop rate increases by 0.3% to 0.5%, and the uplink and downlink HQIs
decrease by 0.6% to 1%.
l If some prerequisite features of this feature have been enabled before S111@1.2MHz
is deployed, impacts on network performance after feature deployment are smaller
than those provided in the preceding table.
l During deployment, after 1.2 MHz networking for BCCH TRXs is enabled, the
immediate assignment success rate may be higher than that on the original network.
An increased immediate assignment success rate allows more MSs to access the
network, increasing network traffic. Most of the new users are very annoyed persons
(VAPs), causing other KPIs, such as the assignment success rate, call drop rate, HQI,
and handover success rate, to deteriorate, which may exceed the specifications in the
preceding table.
Function Impacts
RAT Function
Name
Function
Switch
Referenc
e
Description
GSM TRX
Power
Amplifier
Intelligent
Shutdown
BSCDSTPA.
BSCDynSwit
chTrxPAAllo
w
Intelligent
Power
Consumpt
ion
Decrease
When 1.2 MHz Networking for
BCCH TRXs and TRX Power
Amplifier Intelligent Shutdown are
enabled at the same time, gains
brought by TRX Power Amplifier
Intelligent Shutdown decrease.
GSM BSS

RAT Function
Name
Function
Switch
Referenc
e
Description
GSM IBCA GCELLCH
MGAD.IBC
AALLOWED
IBCA When BCCH TRXs use the 2x3
frequency reuse pattern, there is a
higher probability that interfering
neighboring cell information in MRs
is not reported to the BSC. When this
occurs, the IBCA feature evaluates
channels less accurately, reducing
feature gains.
GSM IBCA II GCELLIBC
AII.IBCAIIA
llowed
IBCA II When BCCH TRXs use the 2x3
frequency reuse pattern, there is a
higher probability that interfering
neighboring cell information in MRs
is not reported to the BSC. When this
occurs, the IBCA II feature evaluates
channels less accurately, reducing
feature gains.
GSM Uplink
CoMP
(Joint RX)
GCELLBAS
ICPARA.Co
MPSwitch
Uplink
CoMP
(Joint RX)
BCCH TRXs and Uplink CoMP
(Joint RX) are both enabled, the
Uplink CoMP (Joint RX) feature
gains decrease, because it does not
support coordination between group
A and group B. However, you are
still advised to enable this feature to
improve uplink voice quality (the
average MOS increases by 0.05 to 0.1
points).
GSM TCHH
repacking
GCELLCH
MGAD.HAL
FRATEREPA
CKINGSWIT
CH
Dynamic
Channel
Conversio
n
The TCHH repacking function in the
Dynamic Adjustment Between FR
and HR feature and the channel group
handover function in the 1.2 MHz
Networking for BCCH TRXs feature
interfere with each other. Ping-pong
handovers will occur when both
functions are enabled. You are not
advised to enable the TCHH
repacking function when the 1.2 MHz
is enabled.
GSM BSS

RAT Function
Name
Function
Switch
Referenc
e
Description
GSM AMR
FR/HR
Dynamic
Adjustme
nt
GCELLHOB
ASIC.INTRA
CELLFHHO
EN
Handover AMR FR/HR Dynamic Adjustment
feature and the channel group
handover function of 1.2 MHz
are mutually impacted. Ping-pong
handovers will occur if both features
are enabled. You are not advised to
enable AMR FR/HR Dynamic
Adjustment when 1.2 MHz
Networking for BCCH TRXs is
enabled.
GSM Enhanced
BCCH
Power
Consumpt
ion
Optimizat
ion
GBTS:
GCELLOTH
EXT.MAINB
CCHPWRDT
EN
eGBTS:
GLOCELLE
NERGYMG
TPARA.MAI
NBCCHPWR
DTEN
Enhanced
BCCH
Power
Consumpt
ion
Optimizati
on
If 1.2 MHz Networking for BCCH
TRXs is enabled, the Enhanced
BCCH Power Consumption
Optimization feature does not take
effect on timeslot 4.
GSM Co-BCCH
Network
GCELL.IUO
TP
Co-BCCH
Cell
BCCH TRXs is enabled, the priority
of channel allocation to the BCCH
TRX is lowered and the probability
of channel allocation to the overlaid
subcell increases, possibly increasing
the call drop rate and decreasing the
HQI.
GSM Multiple
CCCHs
N/A Radio
Resource
Managem
ent
If 1.2 MHz Networking for BCCH
TRXs is enabled, the transmit power
of timeslot 4 on the BCCH TRX will
be decreased. You are not advised to
configure the BCH on timeslot 4.
GSM Dynamic
Multiple
CCCH
GCELLCCC
H.DynCCCH
Switch
Dynamic
Channel
Conversio
n
4.3 Requirements
GSM BSS

4.3.1 Licenses
RA
T
Feature ID Feature Name Model NE Sales Unit
GS
M
GBFD-2002
01
1.2 MHz
Networking for
BCCH TRXs
LGMI12MNB
T
BSC6900
BSC6910
Per Cell
4.3.2 Software
Prerequisite Functions
RAT Function
Name
Function
Switch
Referenc
e
Description
GSM BTS GPS
Synchroni
zation
N/A BTS GPS
Synchroni
zation
1.2 MHz Networking for BCCH
TRXs requires any feature.
NOTE
If GBFD-118620 Clock over IP Support
1588V2 is enabled, this solution requires
only time synchronization of the feature.
GSM Clock
over IP
Support
1588V2
N/A Synchroni
zation
GSM BTS
Support
1588v2
ATR
N/A Synchroni
zation
GSM Soft-
Synchroni
zed
Network
GBTS:
BTSOTHPA
RA.SYNCM
ETHOD and
BTSOTHPA
RA.AISSOP
eGBTS:
BTSOTHPA
RA.SYNCM
ETHOD and
TASM.FLAG
Soft-
Synchroni
zed
Network
GSM BSS

RAT Function
Name
Function
Switch
Referenc
e
Description
GSM User-level
Precise
Power
Control
GCELLPW
RBASIC.Usr
LevPrecisePC
Sw
User-level
Precise
Power
Control
User-level Precise Power Control
reduces downlink transmit power of
the interference source and improves
the downlink voice quality.
If this feature is not enabled, the
downlink HQI of the BCCH TRX
will be 25% to 50% worse and the
BCCH TRX call drop rate will be
10% to 30% higher than when 2.4
MHz networking for BCCH TRXs is
used.
GSM Intelligent
BCCH
Interferen
ce
Suppressi
on (IBIS)
GCELLOTH
PARA.BCCH
IntfSupSw
Intelligent
BCCH
Interferen
ce
Suppressi
on (IBIS)
Intelligent BCCH Interference
Suppression (IBIS) reduces BCCH
TRX downlink interference. If this
feature is not enabled, the downlink
HQI of the BCCH TRX will be 10%
to 20% worse than when 2.4 MHz
networking for BCCH TRXs is used.
GSM MICC GCELLBAS
ICPARA.Mic
cSwitch
Interferen
ce
Cancellati
on
Combinin
g
MICC improves the uplink HQI. If
this feature is not enabled, the uplink
HQI of the BCCH TRX will be 15%
to 30% worse than when 2.4 MHz
GSM Discontin
uous
Transmiss
ion
(DTX)-
Uplink
GCELLBAS
ICPARA.FR
ULDTX and
GCELLBAS
ICPARA.HR
ULDTX
Discontin
uous
Transmiss
ion and
Discontin
uous
Reception
-
GSM Discontin
uous
Transmiss
ion
(DTX)-
Downlink
GCELLBAS
ICPARA.FR
DLDTX and
GCELLBAS
ICPARA.HR
DLDTX
Discontin
uous
Transmiss
ion and
Discontin
uous
Reception
-
GSM Call
Reestablis
hment
GCELLBAS
ICPARA.CA
LLRESTABD
IS
Connectio
n
Managem
ent
Call Reestablishment reduces the call
drop rate. If this feature is not
enabled, the BCCH TRX call drop
rate will be 20% to 40% higher than
when 2.4 MHz networking for BCCH
TRXs is used.
GSM BSS

RAT Function
Name
Function
Switch
Referenc
e
Description
GSM Handover
Re-
establish
ment
GCELLSOF
T.ACTL2RE
EST
Handover
Re-
establish
ment
Handover Re-establishment increases
the handover success rate. If this
feature is not enabled, the BCCH
TRX handover success rate is 10% to
20% lower than when 2.4 MHz
Mutually Exclusive Functions
RAT Function
Name
Function Switch Reference Descripti
on
GSM GTMUb
SingleOM
N/A GTMUb
SingleOM
-
GSM GTMUc
SingleOM
N/A GTMUb
SingleOM
-
GSM BCCH Carrier
Frequency
Hopping
GCELLHOPTP.BCCHTR
XHP
Frequency
Hopping
-
GSM Multi-site Cell N/A Multi-site Cell -
GSM Extended Cell GCELL.EXTTP - -
4.3.3 Hardware
Base Station Models
Table 4-2 NEs supporting the feature
Feature Name BSC6900 BSC6910 GBTS eGBTS
1.2 MHz
Networking for
BCCH TRXs
√ √ √ √
NOTE
l √ indicates that the NE supports this feature. × indicates that the NE does not support this feature.
N/A indicates that this feature is independent of the NE.
l Only 3900 series base stations (excluding the BTS3900B and BTS3900E) and 5900 series base
stations support this feature.
l This feature does not support co-site scenarios.
GSM BSS

Boards
If GPS-based synchronization is used, the BTS must be equipped with the main control board
or USCU board configured with a GPS satellite card.
RF Modules
Only the following RF modules do not support this feature:
DRFU, GRFU, MRFU V1, MRFU V2, MRFU V2a, MRFUd, MRFUe, RRU3004, RRU3008,
RRU3908, RRU3926, RRU3928, RRU3929, RRU3936, RRU3938, RRU3939, RRU3942,
RRU3961, AAU3902, AAU3910, and AAU3911
4.3.4 Networking
l If the wireless network is asynchronous, reconstruct the network into a synchronous
network before enabling this feature.
l Enabling this feature requires configuration of BTS group attributes (specified by the
BTS.TSOFFSETGRP parameter). Before this feature is enabled, divide BTSs into
groups A and B, and place those with large BCCH TRX interference in different groups
based on the BCCH frequency and interference matrix.
NOTE
Groups A and B must be replanned if the BCCH frequency is changed, because they are planned based
on the BCCH frequency.
4.3.5 Others
Enabling this feature creates severe interference on the BCCH TRX. You are advised to limit
the number of SDCCHs and PDCHs on the BCCH TRX to improve performance for voice
services. However, doing so adversely impacts service performance. The following are
SDCCH and PDCH configuration recommendations:
l Recommendations for configuring SDCCHs
– If only one TRX is configured in a cell, preferentially configure the TRX so that it
works in combined BCCH mode. If the TRX cannot be configured to work in this
mode, configure the SDCCH on timeslot 1.
– If more than one TRX is configured in the cell, configure the SDCCH on a TCH
TRX.
l Recommendations for configuring PDCHs
Configure one static PDCH on the BCCH TRX and set GTRXBASE.MAXPDCHNUM
of this TRX to 2.
– For cells under BTSs whose BTS.TSOFFSETGRP is set to GroupA, configure the
PDCH of the BCCH TRX on timeslot 7.
– For cells under BTSs whose BTS.TSOFFSETGRP is set to GroupB, configure the
PDCH of the BCCH TRX on timeslot 2.
4.4 Operation and Maintenance
GSM BSS

4.4.1 When to Use 1.2 MHz Networking for BCCH TRXs
Recommended Application Scenarios
It is recommended that this feature be enabled when BCCH TRXs use the 2x3 frequency
reuse pattern.
Required Information
Before deploying this feature, collect the following information:
No. Information to Be Collected Objective
1 Engineering parametersa, such as the
cell name, longitude and latitude,
azimuth, BTS type, and MA, for cells
Analyze network topology and plan BTS
grouping.
2 Latest BSC configuration files in
these cells
Confirm engineering parameters and plan
groups A and B.
3 Raw performance counters and
historical data in 7 x 24 hours
Obtain the performance counters and
operating status of the original network
for subsequent comparison after 1.2 MHz
Networking for BCCH TRXs is deployed.
4 TRX receive quality performance
counters and historical data in 7 x 24
hours
Obtain the value of RxQuality for
subsequent value comparison after 1.2
MHz Networking for BCCH TRXs is
deployed.
5 Performance counters related to the
interference matrixb of the original
network in 7 x 24 hours
Plan groups A and B.
l a. Obtain the engineering parameters for these cells and compare them to those from the
most recent configuration file. Confirm that these parameters have been configured
completely and correctly. If they are not, rectify them based on the configuration file. If
time permits, visit the BTSs on site to check whether the longitudes, latitudes, and
azimuths of the BTSs are correct. If the GPS has been installed and the GPS works
properly, you can directly obtain the longitudes and latitudes from the GPS.
l b. Obtain the interference matrix in cells where 1.2 MHz Networking for BCCH TRXs is
to be deployed for subsequent planning of groups A and B. BTSs must be divided into
groups A and B during feature activation.
Before deploying 1.2 MHz Networking for BCCH TRXs, collect the counters listed in Table
4-3 to evaluate GSM network performance changes brought by this feature.
GSM BSS

Table 4-3 Required performance counters
Counter Name Counter Description
TRX.FR.DOWN.RX.QLTY.0.NEW NCS412A: Number of MRs on Downlink
TCHF (Receive Quality Rank 0)
TRX.FR.DOWN.RX.QLTY.1.NEW NCS412B: Number of MRs on Downlink
TRX.FR.DOWN.RX.QLTY.2.NEW NCS412C: Number of MRs on Downlink
TRX.FR.DOWN.RX.QLTY.3.NEW NCS412D: Number of MRs on Downlink
TRX.FR.DOWN.RX.QLTY.4.NEW NCS412E: Number of MRs on Downlink
TRX.FR.DOWN.RX.QLTY.5.NEW NCS412F: Number of MRs on Downlink
TRX.FR.DOWN.RX.QLTY.6.NEW NCS412G: Number of MRs on Downlink
TRX.FR.DOWN.RX.QLTY.7.NEW NCS412H: Number of MRs on Downlink
TRX.FR.UP.RX.QLTY.0.NEW NCS413A: Number of MRs on Uplink
TRX.FR.UP.RX.QLTY.1.NEW NCS413B: Number of MRs on Uplink
TRX.FR.UP.RX.QLTY.2.NEW NCS413C: Number of MRs on Uplink
TRX.FR.UP.RX.QLTY.3.NEW NCS413D: Number of MRs on Uplink
TRX.FR.UP.RX.QLTY.4.NEW NCS413E: Number of MRs on Uplink
TRX.FR.UP.RX.QLTY.5.NEW NCS413F: Number of MRs on Uplink
TRX.FR.UP.RX.QLTY.6.NEW NCS413G: Number of MRs on Uplink
TRX.FR.UP.RX.QLTY.7.NEW NCS413H: Number of MRs on Uplink
TRX.HR.DOWN.RX.QLTY.0.NEW NCS414A: Number of MRs on Downlink
TCHH (Receive Quality Rank 0)
TRX.HR.DOWN.RX.QLTY.1.NEW NCS414B: Number of MRs on Downlink
GSM BSS

Counter Name Counter Description
TRX.HR.DOWN.RX.QLTY.2.NEW NCS414C: Number of MRs on Downlink
TRX.HR.DOWN.RX.QLTY.3.NEW NCS414D: Number of MRs on Downlink
TRX.HR.DOWN.RX.QLTY.4.NEW NCS414E: Number of MRs on Downlink
TRX.HR.DOWN.RX.QLTY.5.NEW NCS414F: Number of MRs on Downlink
TRX.HR.DOWN.RX.QLTY.6.NEW NCS414G: Number of MRs on Downlink
TRX.HR.DOWN.RX.QLTY.7.NEW NCS414H: Number of MRs on Downlink
TRX.HR.UP.RX.QLTY.0.NEW NCS415A: Number of MRs on Uplink
TRX.HR.UP.RX.QLTY.1.NEW NCS415B: Number of MRs on Uplink
TRX.HR.UP.RX.QLTY.2.NEW NCS415C: Number of MRs on Uplink
TRX.HR.UP.RX.QLTY.3.NEW NCS415D: Number of MRs on Uplink
TRX.HR.UP.RX.QLTY.4.NEW NCS415E: Number of MRs on Uplink
TRX.HR.UP.RX.QLTY.5.NEW NCS415F: Number of MRs on Uplink
TRX.HR.UP.RX.QLTY.6.NEW NCS415G: Number of MRs on Uplink
TRX.HR.UP.RX.QLTY.7.NEW NCS415H: Number of MRs on Uplink
CELL.RATE.TCH.CALL.DROP.EXCLU
DE.HO
ZTR304A: Call Drop Rate on TCH per
cell(Excluding Handover)
CELL.RD.HO.SUCC.RATE RH303A: Success Rate of Radio Handover
CELL.KPI.TCH.TRAF.ERL.TRAF K3014: Traffic Volume on TCH
CELL.BCCH.TRX.CH.ALLOC.Cap.SO
FTBLK.NUM
S3019A: Number of Capacity-caused Soft
Blocks During BCCH TRX Channel
Allocation
CELL.BCCH.TRX.CH.ALLOC.LEV.SO
FTBLK.NUM
S3019B: Number of Level-caused Soft
Blocks During BCCH TRX Channel
Allocation
GSM BSS

4.4.2 Data Configuration
4.4.2.1 Data Preparation
Table 4-4 describes the parameters used for function activation and optimization.
Table 4-4 Parameters used for activation and optimization
Parameter Name Parameter ID Setting Notes
Channel No. GTRXCHAN.CHNO Set this parameter based on planning
results in 4.3.5 Others.
Channel Type GTRXCHAN.CHTYPE
PDCH Channel
Priority Type
GTRXCHAN.GPRSCH
PRI
Maximum
Number of PDCH
GTRXBASE.MAXPDC
HNUM
Channel Allocate
Strategy
GCELLCHMGBASIC.
CHALLOCSTRATEGY
Set this parameter to CAPABILITY for
hybrid cells and QUALITY for other
cells.
Timeslot Offset
Group
BTS.TSOFFSETGRP Set this parameter based on the grouping
plan.
BCCH TRX
Timeslot
Intelligent
Allocate Switch
GCELLCHMGAD.BCC
HTRXTSIntlAllocateSw
Set this parameter to ON when GSM
BCCH TRXs use the 2x3 frequency
reuse pattern.
BCCH TS4 Power
Decrease
Threshold
GCELLCHMGAD.BCC
HTS4PwrDecrThld
It is recommended that the default value
be used when this feature is enabled.
When this feature is enabled, if the
network performance does not meet the
expectation, check whether the
immediate assignment success rate is
better than that of networks before
feature deployment. If the immediate
assignment success rate is greater than
that before feature deployment, you are
advised to decrease the value of this
parameter by a step of 2 dB. If the
immediate assignment success rate is less
than that before feature deployment, you
are advised to increase the value of this
parameter by a step of 2 dB. Otherwise,
do not adjust this parameter.
GSM BSS

Channel Group
Adjust Switch
GCELLCHMGAD.Cha
nGroupAdjustSw
After this feature is enabled, parameter
reconfiguration can be performed, if
needed, by referring to the impact of this
parameter on the radio network
performance.
Channel Group
Adjust Optimize
Switch
GCELLCHMGAD.Cha
nGroupAdjustOptSw
It is recommended that this parameter be
set to ON(On) only when
GCELLCHMGAD.ChanGroupAdjust
OptSw is set to ON(On).
BCCH TRX
Prefer Allocate
TCHH Switch
GCELLCHMGAD.BCC
HTRXPrefAllocateTCH
HSw
After this feature is enabled, if the traffic
volume on the BCCH carrier is less than
1.5 Erlang and voice service experience
needs improvement, set this parameter to
ON(On).
Channel Allocate
Soft Block
Capacity Thld
GCELLCHMGAD.ChA
llcSoftBlockCapThld
When this feature is enabled, if the traffic
is heavy on the network and causes
network congestion, you can adjust the
value of this parameter to enable the
BCCH TRX to carry more traffic. A
larger value of this parameter leads to
higher traffic carried by the BCCH TRX.
Channel Allocate
Soft Block Call
Level Thld
GCELLCHMGAD.ChA
llcSoftBlockCallLevThld
Retain the default value.
Non-BCCH TRX
Channel Allocate
Priority Policy
GCELLCHMGAD.Non
BCCHTRXChAllcPriPo-
licy
BCCH TRX
Interference
Optimize Policy
GCELLCHMGAD.BCC
HTRXInterfOptPolicy
BCCH TRX TS
Allocate Optimize
Switch
GCELLCHMGAD.BCC
HTRXTSAllocateOptSw
It is recommended that this parameter be
set to ON(On) when
GCELLCHMGAD.ChAllcSoftBlock-
CapThld is set to 100.
GSM BSS

Number of Idle
Channels on
BCCH TRX
GCELLCHMGAD.BCC
HTRXIdleChnlNumber
4.4.2.2 Using MML Commands
Activation Command Examples
//(Optional) Setting the channel type of timeslot 0 of the BCCH TRX:
SET GTRXCHAN: IDTYPE=BYID, TRXID=0, CHNO=0, CHTYPE=CBCCH;
SET GTRXCHAN: IDTYPE=BYID, TRXID=10, CHNO=0, CHTYPE=CBCCH;
//(Optional) Setting PDCHs:
SET GTRXCHAN: IDTYPE=BYID, TRXID=0, CHNO=7, CHTYPE=PDTCH, GPRSCHPRI=EGPRSPRICH;
SET GTRXCHAN: IDTYPE=BYID, TRXID=10, CHNO=2, CHTYPE=PDTCH, GPRSCHPRI=EGPRSPRICH;
//(Optional) Setting the maximum number of PDCHs on BCCH TRXs:
SET GTRXBASE: IDTYPE=BYID, TRXID=0, MAXPDCHNUM=2;
SET GTRXBASE: IDTYPE=BYID, TRXID=10, MAXPDCHNUM=2;
//Setting the channel allocation policies:
SET GCELLCHMGBASIC: IDTYPE=BYID, CELLID=0, CHALLOCSTRATEGY= QUALITY;
//Enabling the BTS grouping function and setting group attributes:
MOD BTS: IDTYPE=BYID, BTSID=0, TSOFFSETGRP=GroupA;
MOD BTS: IDTYPE=BYID, BTSID=1, TSOFFSETGRP=GroupB;
//Turning on the BCCH TRX timeslot intelligent allocation switch:
SET GCELLCHMGAD: IDTYPE=BYID, CELLID=0, BCCHTRXTSIntlAllocateSw=ON,
ChAllcSoftBlockCapThld=70, ChanGroupAdjustSw=OFF, BCCHTS4PwrDecrThld=6,
ChAllcSoftBlockCallLevThld=35, BCCHTRXPrefAllocateTCHHSw=ON,
NonBCCHTRXChAllcPriPolicy=STRATEGY1, BCCHTRXInterfOptPolicy=STRATEGY1;
ChAllcSoftBlockCapThld=70, ChanGroupAdjustSw=OFF, BCCHTS4PwrDecrThld=6,
ChAllcSoftBlockCallLevThld=35, BCCHTRXPrefAllocateTCHHSw=ON,
NonBCCHTRXChAllcPriPolicy=STRATEGY1, BCCHTRXInterfOptPolicy=STRATEGY1;
Optimization Command Examples
//Adjusting the BCCH TS4 power decrease threshold:
BCCHTS4PwrDecrThld=4;
//Adjusting the channel allocation capacity soft block threshold:
BCCHTRXTSAllocateOptSw=ON, BCCHTRXIdleChnlNumber=4, ChAllcSoftBlockCapThld=100;
//Disabling the function of preferentially allocating TCHHs to BCCH TRXs
BCCHTRXPrefAllocateTCHHSw=OFF;
//Enabling the channel group handover function and the channel group handover
optimization function
ChanGroupAdjustSw=ON, ChanGroupAdjustOptSw=ON;
4.4.2.3 Using the CME
l Fast batch activation
This function can be batch activated using the Feature Operation and Maintenance
function of the CME. For detailed operations, see the following section in the CME
product documentation or online help: CME Management > CME Guidelines >
Enhanced Feature Management > Feature Operation and Maintenance.
l Single/batch configuration
This function can be activated for a single NE or a batch of NEs on the CME. For
detailed operations, see CME-based Feature Configuration.
GSM BSS

4.4.3 Activation Verification
On the LMT of the BSC, trace the LOGICAL CELL RECONFIGURATION message on the
OML link (GBTS)/CSL link (eGBTS) over the Abis interface and double-click this message.
If bcch-trx-ts-intl-sllocate-sw is displayed as open, this feature takes effect, as shown in
Figure 4-4.
Figure 4-4 Activation verification
4.4.4 Network Monitoring
Monitor the KPIs listed in Table 4-3 on the GSM side to check the changes after the 1.2 MHz
Networking for BCCH TRXs feature is enabled.
GSM BSS

5Parameter
There are no specific parameters associated with this feature in this RAT.
GSM BSS
Description 5 Parameter

6Counters
There are no specific counters associated with this feature in this RAT.
GSM BSS
Description 6 Counters

7Glossary
For the acronyms, abbreviations, terms, and definitions, see Glossary.
GSM BSS
Description 7 Glossary

8Reference Documents
None
GSM BSS
Description 8 Reference Documents

1.2 m hz networking for bcch trxs(gbss21.1 draft a)

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