omf000410 bsc6000 radio channel management issue1.0
TRANSCRIPT
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Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
BSC6000Radio Channel Management
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Foreword
To satisfy different environments, many kinds of
advance radio resource management algorithms are
adopted, including Huawei II CH allocation algorithm
and TCH/SDCCH conversion. They are designed to
improve the performance of network.
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Objectives
Upon completion of this course, you will be able to:
Master the main idea and parameters of HWII CH Ass.
Algorithm.
Understand TCH/SDCCH conversion.
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Contents
HW II Channel Assignment Algorithm
TCH/SDCCH conversion
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
Contents
HW II Channel Assignment Algorithm
TCH/SDCCH Conversion
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
HW II Channel Assignment Algorithm When the radio resource such as SDCCH and TCH is
required, channel assignment process starts.
HW II channel assignment algorithm is based on
optimum selection. The available channel with
highest overall priority is assigned.
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HW II Channel Assignment Algorithm Processing of
channel assignment
Huawei II Channel Assignment Algorithm
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HW II Channel Assignment Algorithm HW II channel assignment algorithm is based on optimum
selection. The optimum factors are as follows:
1. Different band priority 7. Channel type priority
2. Different TRX priority 8. AMR priority
3. IUO cell TRX property 9. History record priority
4. TRX capability of frequency band 10. Interference priority
5. Channel rate adjustment priority 11. TRX priority
6. Channel rate priority
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HW II Channel Assignment Algorithm Different band priority
This sub-priority is only available for TCH re-assignment.
This priority corresponds to the relationship between the value
of Frequency band of reassign and the frequency band of
current channel and the assigned channel for last time.
Different TRX priority
This sub-priority is only available for TCH re-assignment.
If the TRX of current channel is the same as that of the
assigned channel for the last time, the priority level of
different TRX of the channel is 1; Otherwise, it is 0.
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HW II Channel Assignment Algorithm IUO cell TRX property
The criteria are the same for TCH and SDCCH. This sub-
priority will be 1 just when all of the following
conditions are fulfilled; Otherwise, it is 0.
Current cell is a concentric cell.
The property of current channel is different with the
demanded property which is described in channel
required.
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HW II Channel Assignment Algorithm TRX capability of frequency band
This sub-priority totally has 8 bits. They indicate
DCS1800, PCS1900, GSM480, GSM450, GSM850, R–
GSM, E–GSM and P–GSM.
Corresponding bit is 1, when BCCH frequency band of
current cell and this MS both can support this
frequency band. Otherwise, it is 0.
Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.
HW II Channel Assignment Algorithm Channel rate adjustment priority
This sub-priority is only available for TCH.
This sub-priority depends on the TCH Rate Adjust Allow. If
this parameter is set to YES, this sub-priority is 1; Otherwise, it
is 0.
Channel rate priority
For SDCCH channel, this sub-priority is 0.
If the speech version is AMR, this sub-priority is 0.
Channel rate priority has 2 bits. High bit indicates that whether the channel type is the same as the required one.
Low bit indicates the rate priority.
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HW II Channel Assignment Algorithm Channel type priority
For SDCCH channel, the channel type priority is 0.
For TCH channel, the priority of dynamic PDCH is 1 and
that of other channels is 0.
AMR priority
This one is reserved.
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HW II Channel Assignment Algorithm History record priority
Each successful seizure -1
Once interference occur in each seizure +1
Each failed seizure +2
Each call drop +2
Times refresh
– Timed refresh is used to restore the worsened history record
priority. The history record priority is reduced by a constant at
regular intervals. You can set the interval and the constant.
Usually, a short interval and a small constant are preferred.
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HW II Channel Assignment Algorithm Interference priority
Interference priority depends on the interference band
value.
The channel with less interference is easily assigned
first.
TRX priority
TRX priority depends on the TRX priority level. The
channel with high priority level has low priority and is
difficult to be assigned.
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Parameter Introduction
SD Allocation Priority Allowed Range: Yes, No
Default: Yes
Description: If the setting is "No", then the roll selection is adopted
for SDCCH allocation. If the setting is "Yes", then the optimum
selection is adopted.
Interf. Priority Allowed Range: Yes, No
Default: Yes
Description: Indicates whether the interference record priority is
allowed.
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Parameter Introduction
Active Ch Interf. Meas. Allowed Range: Yes, No
Default: Yes
Description: Indicates whether the interference of the active channel
is measured. If the setting is "No", the system does not judge
whether the active channel is interfered, nor sending interference
indication message. Otherwise, judgment will be made.
Allocation TRX priority allowed Range: Yes, No
Default: Yes
Description: Whether the TRX priority is used for allocation.
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Parameter Introduction History records priority allowed
Range: Yes, No
Default: Yes
Description: Whether the history record priority is used for
allocation.
Balance traffic allowed
Range: Yes, No
Default: Yes
Description: If the setting is "No", the channel next to the
previously allocated channel will be the starting channel for
searching a qualified channel to be allocated.
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Parameter Introduction Interf. of UL Level thrsh.
Range:0~63,(-110dBm~-47dBm)grade
Default:31
Description: Threshold of uplink strength interference. If the uplink strength of a
channel is greater than this threshold and the uplink signal quality is worse than
or equal to the “Interf. of UL Qual. Thrsh.”, then uplink interference exists.
Interf. of UL qual. Thrsh.
Range:0~70, (RQ0~RQ7)
Default:40
Description: Threshold of uplink quality interference. See the description of
“Interf. of UL level Thrsh. “.
Interf. of DL Level thrsh. and Interf. of DL qual. Thrsh.
Are the same as uplink
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Parameter Introduction Filter length for TCH Level
Range:1~32
Default:6
Description: Used to filter the receiving signal strength of speech/data channel.
Filter length for TCH Qual. Range:1~32
Default:6
Description: Used to filter the receiving signal quality of speech/data channel.
Filter length for SDCCH Level and Filter length for SDCCH
Qual. Are the same as previous parameter
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Parameter Introduction Update Period of CH Record
Range:1~1440
Unit: minute
Default: 30
Description: In HW_II channel management algorithm, every
time the duration (set by this parameter) expires, the history
record of every channel will be refreshed through subtracting
the value of “Update Freq. of CH record ". Thus the channel
priority is raised. This parameter together with the "Update
Freq. of CH record " works to prevent a channel from being
allocated again, which has been deteriorated for a period.
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Parameter Introduction
TRX priority Range: Level 0~Level 7
Default: Level 0
Description: The priority of TRX (valid in HW_II channel allocation
algorithm only).
Update Freq. Of CH record Range:0~63
Default:2
Description: The history record priority higher than the value of this
parameter will be refreshed through subtracting the value of this
parameter. See the description of “Update Period of CH record”
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Contents
HW II Channel Assignment Algorithm
TCH/SDCCH Conversion
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TCH/SDCCH Conversion SDCCH dynamic adjustment optimizes the usage of the
traffic channel and signaling channel, reduces the
SDCCH channel block and mitigates the impact on
system performance caused by SDCCH initial
configuration.
The adjustment process is triggered every time before
channel assigning, but the adjusted SDCCH can be only
used in the next occupying quest.
Only support the dynamic adjustment between TCH/F
and SDCCH.
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TCH/SDCCH Conversion After the SDCCH dynamic adjustment process is triggered,
dynamic adjustment can be started under the following
conditions: The time should not be during the resource check.
The BSC internal flow control level should be less than 0.
Dynamic adjustment of other SDCCH in the cell should not be in progress.
“SD Dynamic Allocation Allowed” should be “Yes”.
The cell idle SDCCH number should be smaller than the “Idle SD Thrsh.”.
The number of the SDCCHs +8 should be less than “Cell SD Maximum”.
If the number of the cell idle TCH/F + (the number of the cell idle TCH/H)/2
4 ,and the number of the TRXs in the cell, the dynamic SDCCH adjustment is
not allowed. Otherwise, allowed.
There should be proper Full rate TCH for adjustment.
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TCH/SDCCH Conversion The full rate TCH can be adjusted as the SDCCH only when it meets the
following conditions:
The band class of the frequency should be the sub set of or the
same as the band class of the BCCH frequency.
The initial data configuration of the channel should be full rate
TCH.
The number of SDCCHs on the TRX should be no more than eight.
The channel should be in the occupied state or idle state.
The full rate TCH channel in BCCH carrier of multi TRXs cell
should not be adjustment.
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TCH/SDCCH Conversion If the conditions mentioned above are met, select the full
rate TCH as follows:
None IUO cell Free TCH/F Occupied TCH/F
None 900/1800 hybrid IUO cell Free TCH/F in underlaid cell Occupied TCH/F in underlaid cell
Free TCH/F in overlaid cell Occupied TCH/F in overlaid cell
900/1800 hybrid IUO cell Free TCH/F in underlaid cell Occupied TCH/F in underlaid cell
The inner channel can not be adjusted.
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TCH/SDCCH Conversion
Yes No
NoYes
No
Yes
3 second timertimes out
Idle SDCCHnumber >N1+8?
Yes No
C-3 C+12
C<=0?
Whether there isSDCCH not swtiched
back?
Whether swtichingback is proper ?
Select an SDCCHto Switch back
Restart the 3second timer
Stop the 3second timer
Restart the 3second timer
Start
End
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TCH/SDCCH Conversion
The system decides “whether there is a proper SDCCH
to switch back” according to the following conditions:
All the SDCCHs of the timeslot are occupied or idle.
When the conditions mentioned above are met, select
the SDCCH to adjust in the following two situations If it is not an IUO cell, select randomly an SDCCH adjusted from a
full rate TCH.
If it is an IUO cell, select first the SDCCH adjusted from a full rate
TCH on the UL subcell. If there is no, select the SDCCH adjusted
from a full rate TCH on the OL subcell.
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Parameter Instruction SD Dynamic Allocation Allowed
Range: Yes, No
Default: Yes
Description: Indicates whether SDCCH dynamic allocation is
allowed.
Idle SD Thrsh.N1
Range:0~63
Default:2
Description: When the number of the idle SDCCH is smaller
than this parameter, the TCH can be adjusted to SDCCH.
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Parameter Instruction Cell SD Maximum
Range:0~255
Default: Configured SDCCHs + 8
Description: The maximum number of SDCCHs in the cell.
TCH Min. Recovery Time
Range:60~3600
Unit: Second
Default: 600
Description: The minimum duration for the SDCCH to be
switched back to TCH.
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Summary
In this course, we have learned
HW II channel assignment algorithm.
TCH/SDCCH conversion.
Application should be depended on the real
environment
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