Microsoft PowerPoint - OEO000020 LTE eRAN6.0 Access Fault Diagnsis ISSUE1
Microsoft Power Point - 2 OMF010001 System Information ISSUE1
Transcript of Microsoft Power Point - 2 OMF010001 System Information ISSUE1
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Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
System Information
Page2Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Contents
1. System Information Overview
2. Parameters Introduction
3. Case Study
Page3Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
System Information Overview
� System information (SYS INFO) contains network parameters
sent to MS through Um interface
� network identity parameters
� cell selection parameters
� system control parameters
� network function parameters
� System information can be sent through two kinds of logical
channels
� System information on BCCH
� System information on SACCH
Page4Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Contents
1. System Information Overview
2. Parameters Introduction
3. Case Study
Page5Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Introduction to SYS INFO Parameters
� Huawei GSM System Information Parameters:
� Network Identity Parameters
� System Control Parameters
� Cell Selection Parameters
� Network Functional Parameters
Page6Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Network Identity Parameter — CGI
� Network identity parameters mainly include cell global identity
(CGI) and base station identity code (BSIC).
CGI=MCC+MNC+LAC+CI
� Once MS receives SYS INFO, it decodes the CGI information, and
decides whether it can stay in the cell according to the MCC and
MNC indicated by CGI. At the same time, it judges whether the
current location area is changed, so as to decide whether to
execute location update. During the location update process, MS
will report the new LAI to the network, so that the network can
know the LA in which MS is currently located.
Page7Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Network Identity Parameter — BSIC
� BSIC=NCC+BCC
� In GSM system, each BTS is allocated with a color code, which is
called BSIC. MS can identify two cells with the same BCCH by the
help of BSIC. In network planning, effort should be made to make
sure that BCCH of neighbor cells are different from the serving
cell’s BCCH to reduce the interference. Practically it is still
possible that a same BCCH is re-used in the surrounding cells.
For cells using the same BCCH in a relevant near distance, their
BSIC must be different so that MS can identify two neighbor cells
with same BCCH.
Page8Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Mobile Country Code(MCC)
� Definition
� MCC consists of 3 decimal numbers. It indicates the home
country of the mobile subscriber.
� Format
� MCC is composed of 3 decimal numbers. The coding range is
decimal 000-999.
Page9Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Mobile Network Code(MNC)
� Definition
� MNC is used to uniquely identify a specific GSM PLMN
network in a certain country (decided by MCC).
� Format
� MNC is composed of two decimal numbers. The coding range
is decimal 00-99.
Page10Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Location Area Code(LAC)
� Definition
� To locate the location of MS, the whole area covered by each
GSM PLMN is divided into different location areas. LAC is used
to identify different location areas.
� Format
� LAI contains LAC, which is composed of two bytes. LAC
adopts hexadecimal coding. The available range is from 0001H
to FFFEH. The code 0000H and FFFFH cannot be used
(please refer to specification GSM0303, 0408, and 1111). One
location area can contain one or more cells.
Page11Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Cell Identity(CI)
� Definition
� To uniquely identify each cell in the GSM PLMN, the network
operator needs to allocate one code for each cell, which is the
cell identity (CI). Cell identity, together with LAI, is used for
identity of each cell in the world. (specification 0303).
� Format
� CI is composed of 16 bits, The available range is 0~65535.
Page12Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Network Color Code(NCC)
� Definition
� NCC is a part of BSIC. MS uses it to distinguish adjacent BTS
that belong to different GSM PLMN.
� Format
� NCC is composed of 3 bits, with the range of 0 to 7.
Page13Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
BTS Color Code(BCC)
� Definition
� BCC is a part of BSIC. For its function, please refer to
above sections.
� Format
� BCC is composed of 3 bits. The available range is
from 0 to 7.
Page14Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
System Control Parameters� ATT (Idle Mode)
� CCCH_CONF (Idle Mode)
� BS_AG_BLKS_RES (Idle Mode)
� BS_PA_MFRAMES (Idle Mode)
� T3212 (Idle Mode)
� Neighbor Cell Description (Idle
Mode-BA1&Handover-BA2)
� NCC Allowed (Idle Mode)
� TX-Integer (Idle Mode)
� MS MAX Retrans (Call
Control)
� Radio Link Timeout (Call
Control)
� Common/ Special Access
Control Class (Call Control)
� MBR (Call Control)
� ECSC (Call Control)
Page15Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
ATT
� Value range: Yes, No
� Content:It is used to inform MS whether IMSI attach-
detach is allowed in this cell. If it is set to “Yes”, the network
will not process the connection to the called mobile
subscriber when MS is power-off. Thus network processing
time and radio resources are saved. Otherwise the network
will process the connection even though the MS has been
powered off.
� Recommendation:Yes
Page16Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
CCCH_CONF
� Value range: 1 Non-Compounding CCCH, 1 Compounding CCCH, 2
Non-Compounding CCCHs, 3 Non-compounding CCCHs, 4 Non-
compounding CCCHs.
� Content: It is “Common Control Channel Configuration”. CCCH
configuration determines the capacity of PCH, AGCH and RACH. This
parameter can be automatically configured by the BSC Data Auto
Configuration System according to the TRX channel configuration.
� Recommendation: When there is one TRX in the cell, one combined
CCCH is recommended (in a system with few paging messages in
location area). For others, it is configured according to the number of
TRX in the cell.
Page17Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
BS_AG_BLKS_RES
� Value range: 0~2 (1 combined CCCH), 0~7 (others)
� Unit: Block
� Content: It is also called Access Granted Blocks Reserved.
It is the number of CCCH channel message blocks that are
reserved in one multi-frame for access granted channels
(AGCH).
� Recommendation: 2 (non-combined CCCH)
Page18Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
BS_PA_MFRAMES
� Value range: 2~9
� Unit: Multi-frame period (51 frames)
� Content: It is Paging Channel Multi-frames. It defines the
number of multi-frames used as a cycle of paging sub-
channels.
� Recommendation: 2
Page19Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
T3212
� Value range: 0~255
� Unit: 6 minutes
� Content: It is the Periodic Location Update Timer. It defines the
interval of periodic location update.
� Recommendation: 30 (for urban area), 20 (for suburban area)
Page20Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
LA 1
LA 2
Definition of Location Update
�Inform the system the LA (Location Area) where the MS is to be paged.
Page21Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
LA 2
LA 3
Condition of Location Update
� Periodical location update
� Moving into a new LA
LA 1
Page22Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Procedure of Location Update
BSC
MSC
MS
1 Hour 1 Hour 1 Hour
≥ ++ ++ +
Page23Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Abnormal Occasion
LA 3
LA 2
LA 1
But I am always powered on
The subscriber you dialed has been powered off
Page24Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Reason1 of Abnormal Occasion
BSC
MSC
MS
1 Hour 1 Hour1 Hour
Page25Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Reason2 of Abnormal Occasion
BSC
MSC
MS
1 Hour 1 Hour 1 Hour
≤
Page26Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Application of T3212
Even if T3212 setting is less than the system (MSC) query time, the system
will still sometimes voice “The subscriber you dialed is powered off”.
A B
T3212=4 T3212=8
LAC
“Ping-pong Reselect”
Page27Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Neighbor Cell Description
� There are table BA1 and table BA2.
� Table BA1 describes BCCH frequencies of the adjacent
cells to be measured when the MS is in idle mode.
� Table BA2 describes BCCH frequencies of the adjacent
cells to be measured when the MS is in dedicated mode.
Page28Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Theoretical Neighbor Cells Actual Neighbor Cells
B
CA
D
B
CA
D
Application of Neighbor Cell Description
Page29Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
B
C
A
A
Application of Neighbor Cell Description
Page30Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
NCC Allowed
� Value range: Check box, including options 0~7.
� Content: Network Color Code, sent in system information 2
and 6. It lists NCC that need be measured by MS. If a
neighbor cell’s NCC is permitted, MS will report MRs of it to
the network.
� Recommendation: Subject to the concrete conditions.
Page31Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
MS MAX Retrans
� Value range: 1, 2, 4, 7
� Unit: Time
� Content: It is one of the random access control parameters. MS MAX
Retrans is the upper limit of times that MS is allowed to send “Channel
Request” in one immediate assignment procedure.
� Recommendation:
� Set to 7 for areas with low traffic (suburban or rural area) and the cell radius
more than 3 km.
� Set to 4 for areas with ordinary traffic (non-busy area in the city) and the cell
radius is less than 3km.
� Set to 2 for micro-cell
� Set to 1 for micro-cell with heavy traffic or with obvious congestion.
� Set to 4 or 7 for satellite transmission BTS.
Page32Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
TX-Integer
� Value range: 3~12, 14, 16, 20, 25, 32, 50
� Unit: RACH timeslot (equals to a TDMA frame, 4.615ms)
� Content: Used to calculate the number of timeslots in the
interval between multiple channel requests sent by MS.
� Recommendation: 20 (If the cell immediate assignment
success rate is low, set the S with a larger value. Select 32
for satellite transmission, so as to reduce satellite
transmission delay).
Page33Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Calculation of S
STx-integer
Non-Combined CCCH Combined CCCH
3, 8, 14, 50 55 41
4, 9, 16 76 52
5, 10, 20 109 58
6, 11, 25 163 86
7, 12, 32 217 115
Page34Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Radio Link Timeout
� Value range: 4~64, the step size is 4
� Unit: SACCH period (480ms)
� Content: This parameter is used for MS to decide down-link
disconnection in case of SACCH decoding failures.
� Recommendation: 20~56
Page35Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Application of Radio Link Timeout
Impact of radio link timeout
A B
P Q
Poor coverage
Page36Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Common Access Control Class
� Value range: Check box, including level 0 forbidden,lever 1
forbidden,…, till level 9 forbidden
� Content: One of the parameters of random access control
information. It is used for load control of ordinary
subscribers, to permit or forbid the network access of some
common level users. “1” stands for forbidden and “0” for
permitted.
� Recommendation: 0000000000
Page37Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Special Access Control Class
� Value range: Check box, including level 11
forbidden,level12 forbidden,…, till level 15 forbidden
� Content: It is used for load control, permitting or forbidding
the network access of some special level users. “1” stands
for forbidden and “0” for permitted.
� Recommendation: 00000
Page38Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
MBR
� Value range: 0~3
� Content: Multi-band Reporting. It is used to inform MS to
report the adjacent cells in a controllable way. It is sent in
the System Information 2ter and 5ter.
Page39Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Application of MBR
-92dBm-82dBmA
B
C -68dBm
D -90dBm
E -78dBm
F -88dBm
G -96dBm
H -84dBm
GSM1800
GSM900S
Page40Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
ECSC
� Value range: Yes, No
� Content: Early Classmark Sending Control. It indicates if an
MS in the cell is allowed to use early Classmark sending.
See Protocol 0408.
� Recommendation: No.
Page41Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Cell Selection Parameter
� CBQ (Cell Bar Qualify)
� CBA (Cell Bar Access)
� MS_TXPWR_MAX_CCH
� RXLEV_ACCESS_MIN
� PI (Cell Reselect Parameters Indication)
� CRO (Cell Reselection Offset)
� TO (Temporary Offset)
� PT (Penalty Time)
� CRH ( Cell Reselection Hysteresis)
Page42Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Cell Selection Process
� There are two kinds of cell selection.
� Normal cell selection
� Stored list cell selection
� In fact, the process might be different for different MSs
Page43Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Stored List Cell Selection
Search the BCCH
which have been
stored
Can not find it
Normal cell
selection
Can find it
Can reside in it
Can’t reside ,search
neighbor cell
Come into
idle mode
NO
YES
Page44Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Normal Cell Selection
Search all frequency
Rank according to receiving level
Come into idle
mode
Check whether this is a BCCH carrier, get
SCH and decode system information
PLMN, C1>0, priority is normal
YES
Check next one
NO
NO
YES
Page45Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Normal Cell Selection
Check the next frequency by the same step
Check the cell which priority is low, C1>0,PLMN
Come into idle
modeTry the cell which PLMN is allowed
in the SIM card
Stay at a cell which RX-LEV is strongest,
C1>0 , cell priority is not prohibitedEmergency
call mode
NO
NO
YES
YES
YES
NO
YES
Page46Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Cell Selection Parameter
C1=RLA_C-RXLEV_ACCESS_MIN-
MAX((MS_TXPWR_MAX_CCH - P), 0)
RLA_C: Receiving level of MS
RXLEV_ACCESS_MIN: Minimum receiving level of MS permitted to access
P: Maximum Physical supported transmitting power of MS.
Page47Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
RXLEV_ACCESS_MIN
� Value range: 0~63
� Unit: Level
� Content: It means the minimum receive signal level
required for MS to access a cell.
� Recommendation: 8
Page48Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
MS TXPWR_MAX_CCH
� Value range: 0~31
� Unit: level
� Content: This parameter determines the maximum
allowed output power of the MS when it begins to
access a cell and has not yet received power
control command.
� Recommendation: 5(900MHz), 0(1800MHz)
Page49Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
CBQ
� Value range: Yes , No
� Unit: None
� Content: Cell Bar Qualify. CBQ only affects the selection
of cells but is not related to cell reselection. It works with
CBA to define the access priorities of cells.
� Recommendation: No.
Page50Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
CBA
� Value range: Yes, No
� Content: Cell Bar Access, worked together with CBQ to set
the priority status of the cell in idle mode for cell selection
and reselection.
� Recommendation: Yes
Page51Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Application of CBA and CBQ
normallow11
normallow10
forbiddenforbidden01
normalnormal00
Cell reselectionpriority
Cell selection priorityCBQCBA
Page52Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Application of CBQ
The traffic of cell A and B is heavy. Set these two cells with CBA=“1”, CBQ=“0”.
A B
Page53Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Application of CBA
B is a micro cell. Set B to “Normal” and A to “Low”.
B
A
Page54Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Cell Reselection Process� Cell reselection for cells in same location area
� If the C2 value of the target cell is higher than that of the serving cell for longer
than 5 seconds, a cell reselection process will be performed and the MS tunes
to the new cell.
� Cell reselection for cells in different location areas
� If the C2 value of the target cell is higher than that of the serving cell by at least
the value of CRH for longer than 5 seconds, a location update process and the
cell reselection process will be performed.
� Two consecutive cell reselections caused by C2 have a time interval of 15
seconds. In other words to say, if because of C2 a MS reselected to a cell,
then the MS cannot reselect to another cell by the cause of C2 within 15
seconds.
� If current serving cell is prohibited, or down link fails, or C1 is less than 0
continuously for 5s, cell reselection will also be triggered.
� MS starts a cell reselection if the access times exceed the MAX retrans.
Page55Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Cell Reselection Parameter
C2=C1+CRO-TO*H(PT-T) When PT is not equal to 31
C2=C1-CRO When PT is equal to 31
Function H(x)=0, when x<0; H(x)=1, when x>0
Page56Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
PI
� Value range: Yes (1), No (0).
� Unit: None
� Content: Cell Reselect Parameters Indication, sent
on the broadcast channel of the cell. It is an
indication to the existence of “Cell Reselect
Offset(CRO)”, “Temporary Offset(TO)” and
“Penalty Time(PT)”.
� Recommendation: Yes
Page57Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
CRO
� Value range: 0~63, the corresponding level value:
0~126dB, stepped every 2dB.
� Unit: None
� Content: Cell Reselect Offset. It is a parameter in
C2 calculation to give an intentional modification in
MS cell reselection.
� Recommendation: 0
Page58Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
TO
� Value range: 0~7 , the corresponding value is
0~60dB, 7 corresponds to “Infinite”.
� Unit: None
� Content: Cell Reselect Temporary Offset. It is a
parameter in C2 criterion to give a temporary
modification within PT time.
� Recommendation: 0
Page59Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
PT
� Value range: 0~31, the corresponding time is
20~620s. 31 is to change the formula of C2.
� Unit: None
� Content: Cell Reselect Penalty Time.
� Recommendation: 0
Page60Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
CRH
� Value range: 0~14 , the step size is 2
� Unit: dB
� Content: Cell Reselection Hysteresis. It is the parameter
used when cell reselection happens between two location
areas.
� Recommendation: 4
Page61Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Network Function Parameter
� PWRC (Power Control Permitted)
� Other Attributes/Public Channel Control
� UL DTX (Uplink Discontinuous Transmission)
� Cell Attributes
� Call Re-establishment Forbidden (RE)
� Cell Attributes
� EC Disabled (Emergency Call Disabled)
� Call Control
Page62Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
PWRC
� Value range: Yes, No.
� Unit: None
� Content: It is used to indicate MS weather to reduce received level
value obtained from the timeslots of BCCH when MS measures
receiving level during base band hopping mode. When it is set to
“No”, it means the influence of receiving level on BCCH is not in
consideration. If it is set to “Yes”, process it in the way mentioned
above.
� Recommendation: Yes
Page63Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
UL DTX
� Value range: May use, Shall use, Shall not use.
� Unit: None
� Content: It is used to indicate whether MS uses DTX
function. In System Information 3, it is 2-bit coding. In
System Information 6, it is 3-bit coding. It shows the DTX
state of the MS in the previous measurement period.
� Recommendation: Shall use
Page64Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Call Re-establishment Forbidden
� Value range: Yes, No
� Unit: None
� Content: Informing MS whether call reestablishment is
allowed or not.
� Recommendation:Yes
Page65Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
EC Disabled
� Value range: Yes, No
� Unit: None
� Content: Emergence Call Allowed . When EC Allowed is set
to “Yes”, it means emergency call is permitted. Otherwise it
is prohibited.
� Recommendation: No
Page66Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Contents
1. System Information Overview
2. Parameters Introduction
3. Case Study
Page67Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Case Study� Case 1: Island effect
� Case Description
� During the process of optimization in a certain area, it is found out
that the signal is poor in a certain section of suburban highway.
The signal strength measured is less than -95dBm.
� Handling Procedure
� Modify the data in BSC. Add neighbor relationship to Cell A and B
for each other. The coverage problem is thus solved.
C
B
A-92
-80
-95
Page68Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Case Study� Case 2: Incorrect CGI causes MS unable to register on the network.
� Case description
� The subscriber complained that MS could not register to the network, or it was
difficult to register to the network between BTS A and B, or no network mark
was displayed on the MS, but MS indicated that the signal was very good.
Some subscribers also complained that MS could make MTC could not make
MOC.
� Cause analysis
� CGI of the cell was modified. So the network register flow was not normal.
Although the signal was very good, MS could not get registered in the network.
� Recommendation and summary
� CGI is a very important parameter and should be configured correctly, thus to
ensured that the CGI data in BSC and MSC are the same.
Page69Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Case Study
� Case 3: RXLEV_ACCESS_MIN causes signal fluctuation.
� Case description
� Subscribers complain that the signal fluctuates in a certain area. On-site test shows
that this phenomenon does exist. From the testing mobile, we can see that there are a
lot of cells’ signals in this area. Some frequencies are the suburb BTS signals far
away from this area. The cell reselection of MS is rather frequent.
� Handling procedure
� Modify parameter “RXLEV_ACCESS_MIN” of all cells in urban area and make them
consistent with each other. The problem of signal fluctuation is solved.
� Recommendation and summary
� In area with complicated coverage, the “RXLEV_ACCESS_MIN” of each cell should
be kept same.
Page70Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Case Study
� Case 4:Too small T3212 causes MS lose connection with
network.
� Case description
� A local GSM network has more than 6000 subscribers. There are four
BTSs. The network has been working properly. But from sometime on,
some MS often lost connection with network suddenly. The complaint from
subscribers in urban area increased.
� Handling procedure
� Modify T3212 to 10, i.e. 60 minutes. Modify the corresponding time of MSC
to 180 minutes. Two days’ observation shows no subscriber complaint and
the problem is solved.
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