179846784 2g huawei performance monitoring

5/20/2018 179846784 2G Huawei Performance Monitoring

1/701 Nokia Siemens Networks Presentation / Author / Date

For internal use

HUAWEI 2G PERFORMANCE

MONITORING AND ANALYSIS



For internal use

Contents

1. Overview

2. 2G Performance Monitoring and Analysis



For internal use

Document Information

Document Version:1.0

Issue Date:September 8, 2010

Author:Christos Kyriazopoulos

Document Owner:Ville Salomaa

SOFTWARE RELEASE:GBSS9.0

SCOPE:2G performance monitoring and analysis

CONVENTION:

Raw counters are marked in BLUE

Formulas are marked in GRAY

Parameters are marked in RED

MML commands are marked in GREEN



For internal use

Contents

1. Overview

2. 2G Performance Monitoring and Analysis



For internal use

Overview

The purpose of this document is to describe the BSS KPI performance monitoring and analysis of problems

that bad KPI values indicate.

The following analysis contains a list of the most common KPIs used in Huawei networks. These KPIs are

monitored constantly. When the value of a KPI goes below the defined threshold, then detailed analysis

should be performed in order to identify the reasons of this deterioration. Once the reasons are found, proper

solutions will be proposed and implemented.

This document focuses more in the analysis of failure causes rather than the KPI monitoring itself.

The most common use cases for monitoring and analysis of bad values are presented for 2G BSS.



For internal use

2G Performance Analysis Use Cases

2G Performance Analysis Use Cases:

CS:

1.High SDCCH Blocking

2.High SDCCH Drop rate

3.CSSR

4.High TCH blocking

5.High TCH Drop call rate

6.High HO fail

7.Low Coveragehow to identify coverage problems (e.g. TA vs. cell radius, Rxlevel measurements, HO

distribution)8.High Interferencehow to identify interference problem in cell (idle UL interference, Rxlevel & Quality

distributions, TA measurements)

PS:

9.High Signaling Failures Before TBF Establishment

10.High TBF Establishment Failures

11.High TBF Drops

12.Low Throughput (Um, Abis, PCU, Gb)



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General Methodology

General Methodology:

1. Define BSS KPI class required (Accessibility, Retainability, Mobility, Resource Usage).

2. Define KPI per service (Voice, Packet Service).

3. Define KPI formulas.

4. Define target or guaranteed KPI values.

5. Assess weekly average PLMN/BSC KPI performance in order to identify KPIs below target.

6. Assess BSC/Area level performance in order to check if bad performance occurs across network or only in

specific areas.

7. Analyze bad perform ing K PIs in c el l level in order to ident i fy fa i lure causes. (this point is the focus of

this document)8. Use TopN cell approach to identify the worst performers. Identify top 20 worst cells.

9. Look at failure distribution in network topology (urban, rural, motorway, RNC border, etc.).

10. Propose solution to improve KPI value.



For internal use

Contents

1. Overview

2. 2G Performance Mon itor ing and Analysis



For internal use

1. High SDCCH Blocking (1)

- KPI formula:

SDCCH Congestion Rate (Overflow)= ([Failed SDCCH Seizures due to Busy SDCCH]/[SDCCH Seizure

Requests])*{100}

Analysis process:

1.High SDCCH blocking is due to congestion on the SDCCH channel. Check what causes the high SDCCH

usage. Then appropriate actions can be taken:

Check Call Setups:

- CELL_ESTB_IND_MOC_NONSMS_SD: Number of Call Setup Indications for MOC on SDCCH

- CELL_ESTB_IND_MTC_SD: Number of Call Setup Indications for MTC on SDCCH

Check amount of SMS. Check and verify with Core engineers SMS Center parameterization.

-A3030B: CELL_ESTB_IND_MOC_SMS_SD: Number of Call Setup Indications for SMS on

SDCCH

- CA3340: CELL_Pt_to_Pt_SMS_SD: Number of Point-to-Point Short Messages on SDCCH

(includes

UL+DL)

Check LAU/RAU requests:

-A300F: CELL_CH_REQ_LOC_UPDATE: Number of Channel Requests for Location Update

-A3030F: CELL_ESTB_IND_LOC_UPDATE_SD: Number of Call Setup Indications on SDCCH

for Location Update.



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2. If high SCDDH usage is due to LAU then:

Check if the problem is caused by roamers that do not have access to the network, thus causing big

amount of failed LAUs/RAUs.

Check if cell is in LA border: if yes, then we can increase CRHparameter value

- CRH:Cell Reselect Hysteresis Parameters (Cell reselection hysteresis. This is one of the parameters

used for deciding whether to reselect cells in different location areas.)

Check LA border planning. Verify LA borders by checking HO statistics between cells in LA border:

- H380:CELLCELL_INCELL_HO_REQ: Incoming Inter-Cell Handover Requests between 2 cells

Check the value of T3212; if too low, increase

- T3212:T3212 (This parameter specifies the length of the timer for periodic location update).

Recommended value: as high as possible, usually 4h.

Check whether moving LA borders (if possible to move) could help relieving the congestion.

Check the pattern of LAU requests. Check hours and duration of high number of such requests.

Check whether the problem is constant throughout the day or it occurs only during 1 hour for example.

If the problem occurs only on specific hour of day check if it is worth acting to solve it (costs vs.

benefits).



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3. Check if TCH Immediate Assignment is allowed:

- IMMASSEN: TCH Immediate Assignment (Whether to allow immediate TCH assignment. If this

parameter is set to YES, the BSC can assign a TCH immediately when there is no available SDCCH for

a channel request.) Note: It is not recommended to activate this in congested LA borders.

4. Activate SDCCH dynamic conversion feature: Dynamic SDCCH conversion can be triggered if the

SDCCH resource is insufficient or the SDCCH allocation fails during the channel assignment

- SDDYN:SDCCH Dynamic Allocation Allowed (Whether to allow SDCCH dynamic allocation, that is,

whether to allow dynamic conversion between TCHs and SDCCHs.)

- IDLESDTHRES:Idle SDCCH Threshold N1 (When the number of idle SDCCH channels in a cell is

smaller than this parameter, the system searches for available TCHs and transforms them into SDCCHchannels)

- CELLMAXSD:Cell SDCCH Channel Maximum (Maximum number of SDCCHs in the cell. Before

converting a TCH into an SDCCH, the BSC compares the number of SDCCHs after the conversion in

the cell with "Cell SDCCH Channel Maximum". If the number of SDCCHs after the conversion in the cell

exceeds this parameter, the BSC does not convert the TCH into an SDCCH.)

5. Add SDCCH/8 channel

6. Add TRX

Note:for more details on SDCCH capacity optimisation check HUA_2G_Capacity_Optimization_v1.0.pptx

document from Multivendor Team in IMS.



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2. High SDCCH Drop Rate (1)

- KPI formula:

SDCCH Drop Rate= ([Call Drops on SDCCH]/[Successful SDCCH Seizures])*{100}

Analysis process:

1.Identify the route cause of SDCHH drops by checking the following counters. The total number of

SDCCH drops is given by:

Call Drops on SDCCH = [Call Drops on Radio Interface (SDCCH)]+[Call Drops due to No MRs from MS for a

Long Time (SDCCH)]+[Call Drops due to Abis Terrestrial Link Failure (SDCCH)]+[Call Drops Due to

Equipment Failure (SDCCH)]+[Call Drops due to Forced Handover (SDCCH)]:

Call Drops on Radio Interface (SDCCH): the drop is due to radio. Check for missing neighbours. Checkradio environment/signal strength at drop points. Adjust antenna parameters appropriately to improve

coverage if this is the problem. Check whether the drops are during handover. Check interference.

Call Drops due to No MRs from MS for a Long Time (SDCCH): After seizing an SDCCH, the MS sends a

measurement report to the BSC every 470 ms. When the BSC does not receive a measurement report

within a certain period of time, the BSC sends a CLEAR REQUEST message to the MSC to release the call,

and this counter is incremented by one. Check UL coverage and quality (interference). Check for possible

MS problem.

Call Drops due to Abis Terrestrial Link Failure (SDCCH): transmission problem on Abis. Check relative

alarms.

Call Drops Due to Equipment Failure (SDCCH): BSC hardware or software failure. Check alarms to

discover the exact cause.



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2. High SDCCH Drop Rate (2)

Call Drops due to Forced Handover (SDCCH): After an MS seizes a channel, if the system initiates a

forced handover and the handover fails, the BSC may initiate a call release procedure. Check why the

handover failed: Timer expired? Check whether the emergency handover is due to preemption, or

blocking of cell/TRX/channel.


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14 Nokia Siemens Networks Presentation / Author / Date

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3. CSSR (1)

- KPI formula:

BSS Call Setup Success Rate= (([Immediate Assignment Success Rate]*[TCH Assignment Success

Rate])*(1-[SDCCH Drop Rate]))*{100}

The CSSR combines 3 other KPIs:

- Immediate Assignment Success Rate= ([Call Setup Indications (Circuit Service)]/[Channel Requests

(Circuit Service)])*{100}

- TCH Assignment Success Rate= ([Successful Assignments]/[Assignment Requests])*{100}

- SDCCH Drop Rate= ([Call Drops on SDCCH]/[Successful SDCCH Seizures])*{100}

Analysis process:1.Each of the 3 component-KPIs will affect CSSR:

- Low Immediate Assignment Success Rate will decrease CSSR

- Low TCH Assignment Success Rate will decrease CSSR

- High SDCCH Drop Ratewill decrease CSSR

2.Examine at which point most of the failures appear by checking thoroughly the 3 component-KPIs.

Find out the corresponding failure causes for Immediate Assignment, Assignment and SDCCH Drops.


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3. CSSR (2)

3. Low Immediate Assignment Success Rate

Basic Immediate Assignment signalling procedure:

Fig.1 Successful Immediate Assignment Fig.2 Failed Immediate Assignment

A: The BSC sends an IMM ASS REJ message due to noavailable channel

B: The BSC sends an IMM ASS REJ message due to

channel activation failure

C: The BSC sends an IMM ASS REJ message due to

channel activation timeout


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3. CSSR (3)

If Immediate Assignment failures are due to no channel available (point A in Figure 2), this means that there

is SDCCH congestion. Refer to Case 1 of present document for handling.

If Immediate Assignment failures are due to channel activation failure or channel activation timeout (points

B, C in Figure 2) check hardware/software alarms.

4.Low TCH Assignment Success Rate

Basic Assignment signalling procedure:


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3. CSSR (4)

Check following counters to identify the reason for Assignment failure:

(1) Failures due to mismatch between the state machine of the BSC and the ASS REQ message or due to

the abnormality of the ASS REQ message:

-A3129I: CELL_ASS_FAIL_INVALID_STATE: This counter provides the number of ASS FAIL messages sent

by the BSC to the MSC when the BSC receives an ASS REQ message that is not expected by the internal

state machine of the BSC (for example, the state machine is in release status).

-A3129J: CELL_ASS_FAIL_INVALID_MSG_CONTENTS: This counter provides the number of ASS FAIL

messages sent by the BSC to the MSC when the BSC receives an ASS REQ message but the ASS REQmessage fails to be decoded (for example, an error occurs during the decoding of an IE, such as CHANNEL

TYPE, CIC, or Layer 3 header information).

-A3129E: CELL_ASS_FAIL_NO_CIC: This counter provides the number of ASS FAIL messages sent by the

BSC to the MSC when the BSC receives an ASS REQ message that carries an unavailable A interface CIC.

-A3129F: CELL_ASS_FAIL_CIC_ALLOC: This counter provides the number of ASS FAIL messages sent by

the BSC to the MSC when the BSC receives an ASS REQ message that carries an A interface CIC that is

already occupied by another call.


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3. CSSR (5)

(2) Failures due to abnormal radio resource allocation:

-A312A: CELL_ASS_FAIL_Frst_ASS_NO_CH: This counter provides the number of ASS FAIL messages

sent by the BSC to the MSC when the cell does not have available channels and the directed retry

procedure fails to be initiated or the directed retry is prohibited by the data configuration in the first air

interface assignment procedure.

-A312L: CELL_ASS_FAIL_RECONN_SUCC_ASS_NO_CH: This counter provides the number of ASS FAIL

messages sent by the BSC to the MSC when the cell does not have available channels and the directed

retry procedure fails to be initiated or the directed retry is prohibited by the data configuration in the air

interface assignment procedure except for the first air interface assignment procedure.

-A312K: CELL_ASS_FAIL_Frst_DR_NO_CH: This counter provides the number of ASS FAIL messages

sent by the BSC to the MSC when the cell does not have available channels and the directed retry

procedure is successfully initiated but failed due to no available channel in the first air interface assignment

procedure.

-A312M: CELL_ASS_FAIL_RECONN_SUCC_DR_NO_CH: This counter provides the number of ASS FAIL

messages sent by the BSC to the MSC when the BSC attempts to make a directed retry but the directed

retry failed because the target cell does not have available channels in the air interface assignment

procedure except for the first air interface assignment procedure.


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3. CSSR (6)

-A312F: CELL_ASS_FAIL_NO_IDLE_ABIS: This counter provides the number of ASS FAIL messages sent

by the BSC to the MSC when the dynamic allocation of Abis resources is enabled on the BSC but the

assignment fails due to no available Abis resources.

-A3129S: CELL_ASS_FAIL_NO_SPEECH_VER: This counter provides the number of ASS FAIL messages

sent by the BSC to the MSC when the assignment fails because the intersection between the speech

version set carried in the ASS REQ message from the MSC and the speech version set supported by the

current cell of the MS does not have available speech versions.

(3) Failures due to abnormal air interface access:

-A3129C: CELL_ASS_FAIL_Frst_ASS_EXP: This counter provides the number of ASS FAIL messages sent

by the BSC to the MSC when the timer for the BSC to wait for an ASS CMP message expires after the BSC

sends an ASS CMD message to the MS in the first air interface assignment procedure.

-A3129P: CELL_ASS_FAIL_RECONN_SUCC_ASS_EXP: This counter provides the number of ASS FAIL

messages sent by the BSC to the MSC when the timer for the BSC to wait for an ASS CMP message

expires after the BSC sends an ASS CMD message to the MS in the air interface assignment procedure

except for the first air interface assignment procedure.


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3. CSSR (7)

-A3129O: CELL_ASS_FAIL_Frst_DR_EXP: This counter provides the number of ASS FAIL messages sent

by the BSC to the MSC when the cell does not have available channels and the directed retry procedure is

successfully initiated but failed due to the expiry of the timer for waiting for an HO CMP message in the first

air interface assignment procedure.

-A3129Q: CELL_ASS_FAIL_RECONN_SUCC_DR_EXP: This counter provides the number of ASS FAIL

messages sent by the BSC to the MSC when the timer for waiting for an ASS CMP message expires after

the BSC sends an HO CMD message to the MS in the air interface assignment procedure except for the first

air interface assignment procedure.

-A3129D: CELL_ASS_FAIL_RECONN_SUCC_ASS_RECONN_SUCC: This counter provides the numberof ASS FAIL or RR STATUS messages reported by the MS to the BSC when the MS attempts but fails to

access the new channel and then successfully reconnects to the old channel after receiving an ASS CMD

message.

-A3129R: CELL_ASS_FAIL_RECONN_SUCC_DR_RECONN_SUCC: This counter provides the number of

HO FAIL or RR STATUS messages reported by the MS to the BSC when the MS attempts but fails to access

the new channel and then successfully reconnects to the old channel after receiving an HO CMD message.


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3. CSSR (8)

(4) Failures due to the abnormality of terrestrial resources or the call clearing performed by the MSC.

-A3129B: CELL_ASS_FAIL_Frst_APPLY_TRSL_FAIL: This counter provides the number of ASS FAIL

messages sent by the BSC to the MSC when the MS drops from the connection to the air interface, or a

circuit fails to be obtained for the call, or the obtained circuit is faulty during the circuit connection of the BSC

in the first air interface assignment procedure.

-A3129N: CELL_ASS_FAIL_RECONN_SUCC_APPLY_TRSL_FAIL: This counter provides the number of

ASS FAIL messages sent by the BSC to the MSC when the MS drops from the connection to the air

interface, or a circuit fails to be obtained for the call, or the obtained circuit is faulty during the circuit

connection of the BSC in the air interface assignment procedure except for the first air interface assignmentprocedure.

-A3129G: CELL_ASS_FAIL_A_INTERF_FAIL: This counter provides the number of times that the BSC

locally releases the call when the BSC receives an SS7 link abnormality indication in the assignment

procedure.

-A3129H: CELL_ASS_FAIL_MSC_CLR_CMD: This counter provides the number of times that the BSC

releases the call after receiving a CLEAR CMD message from the MSC in the assignment procedure.


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3. CSSR (9)

5. High SDCCH Drop Rate

In case high SDCHH Drop Rate causes deterioration of CSSR, refer to Case 2 of present document for

handling.

6. Parameters that affect CSSR

- RACHACCLEV: RACH Min. Access Level

This parameter affects the coverage area. If this parameter is set to a higher value, the actual coverage area

of the network becomes small; if this parameter is set to a lower value, call drops are likely to occur

because of invalid access or too weak access signals, thus decreasing the success rate of BSS callsetup.

- RACHBUSYTHRED: RACH Busy Threshold



because of invalid access or too weak access signals, thus decreasing the success rate of BSS call

setup.

- RANERRTHRED: Random Access Error Threshold



because of invalid access or too weak access signals, thus decreasing the success rate of BSS call

setup.

- CIC No.The values of CICs must be consistent with that on the MSC side.


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3. CSSR (10)

7. Network functions that affect CSSR

- Directed retry

When TCHs in a cell are insufficient, TCHs in other cells can be assigned through directed retry, thus

increasing the BSS CSSR. By default, this function is enabled.

- SDCCH dynamic adjustment

When SDCCHs are insufficient, this function can be enabled to convert some TCHs into SDCCHs to

increase the success rate of immediate assignment, thus increasing the BSS CSSR. By default, this

function is enabled.

- TCH reassignment

When this function is enabled, the BSC initiates a re-assignment procedure after receiving the failure

indication of the TCH assignment on the Um interface. This function can be used to increase the

success

rate of TCH assignment, thus increasing the BSS CSSR. By default, this function is enabled.

- Flex Abis

This function is implemented in the BSC6000V900R003 and later versions. This function enables dynamic

assignment of Abis timeslots to more efficiently utilize the Abis link resources; however, assignment may

fail because of congestion on the Abis links. This function may decrease the BSS CSSR.


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4. High TCH Blocking (1)

- KPI formula:

TCH Congestion Rate (Overflow)= (([Failed TCH Seizures due to Busy TCH (Signaling Channel)]+[Failed

TCH Seizures due to Busy TCH (Traffic Channel)]+[Failed TCH Seizures in TCH Handovers due to Busy

TCH (Traffic Channel)])/([TCH Seizure Requests (Signaling Channel)]+[TCH Seizure Requests (Traffic

Channel)]+[TCH Seizure Requests in TCH Handovers (Traffic Channel)]))*{100}

Analysis process:

1.High TCH blocking means congestion on the Traffic Channel: there are not enough free TCHs to accept

new service requests.

2.Check cell traffic channel availability in order to verify that congestion is not due to availability issue. Checkcell alarms.

3.Check availability of neighboring sites. If neighboring cells are unavailable this will cause big amount of

HOs directed to our current cell thus leading to congestion.

4.Check cell traffic channel configuration. Check if all HR resources are in use before TCH congestion

occurs. Verify that HR is enabled. In case AMR is supported by the operator, verify that is enabled.

5.Load balancing between cells: certain features can be activated to manage the traffic sharing between

cells:

- Enable LO handover algorithm: LoadHoEn: Load Handover Support

- Enable Directed Retry due to load: DIRECTRYEN: Directed Retry


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6. Load balancing between cells:

- Concentric Cells:check relative parameters so as to implement optimal traffic sharing between

underlaid-overlaid cells.

- Enhanced Dual Band Network:check relative parameters so as to implement optimal traffic sharing

between underlaid-overlaid cells.

7. Check if additional capacity related features can be activated in the network in order to improve the

utilisation of TCH resources:

- BCCH Dense Frequency Multiplexing:enables the BCCHs to reuse frequencies more tightly to free

more frequencies for non-BCCH TRXs, thus increasing the system capacity.

TIGHTBCCHSWITCH: TIGHT BCCH Switch (Whether to enable the BCCH aggressive frequency reusealgorithm)

- Interference Based Channel Allocation (IBCA):The IBCA algorithm requires the BSC to estimate the

C/I ratio of the new call in every channel assignment procedure; it also requires the BSC to estimate the

interference caused to the established calls on the network when an idle channel is assigned to a new

call. In this way, the optimal channel, that is, the one that meets the C/I ratio requirement of the new call

and causes the least interference to the established calls after being occupied, is assigned to the new

call to alleviate the interference and ensure the full use of the frequency resources.

IBCAALLOWED: IBCA Allowed (Whether to enable the IBCA algorithm)- Flex MAIO:BSC dynamically adjusts the MAIO according to the current interference level of a channel

when assigning an MAIO to the channel .

FLEXMAIO: Start Flex MAIO Switch (Whether to enable the function of Flex Mobile Allocation Index

Offset)


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8. If congestion is still present although the previous described fine tuning and features activation, then:

- Check Interference in the network (C/I); check frequency plan

- Check coverage: maybe network layout should be changed in traffic hot spots

- We can use TA distribution in order to identify traffic distribution among cells. In some cases

overshooting can be detected, so we can check the possibility to reduce service area of the

overshooting cell. Before doing so, we need, of course, to make sure that there is clear dominance in

the area that we are going to shrink serving cells coverage.

- Implement physical network changes where necessary and feasible: tilt, azimuth, antenna type, etc.

- Add TRX

- Long term monitoring (e.g. one month) can be used to identify whether we have constant growth in

traffic in a site and area close by. If traffic increases in area level and we have already high HR/AMR HR

utilization then there are not too many other options than implement a new site.

- Add Site

Note:for more details on TCH capacity optimisation check HUA_2G_Capacity_Optimization_v1.0.pptx

document from Multivendor Team in IMS.


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5. High TCH Drop Call Rate (1)

- KPI formula:

TCH Call Drop Rate (including handovers)= ([Call Drops on TCH]/([Successful TCH Seizures (Signaling

Channel)]+[Successful TCH Seizures (Traffic Channel)]+[Successful TCH Seizures in TCH handovers

(Traffic Channel)]))*{100}

Analysis process:

1.Identify the route cause of the call drops by checking the Call Drops on TCHcounter:

Call Drops on Traffic Channel=

[Call Drops on Radio Interface in Stable State (Traffic Channel)]+

[Call Drops on Radio Interface in Handover State (Traffic Channel)]+[Call Drops due to No MRs from MS for a Long Time (Traffic Channel)]+

[Call Drops due to Abis Terrestrial Link Failure (Traffic Channel)]+

[Call Drops due to Equipment Failure (Traffic Channel)]+

[Call Drops due to Forced Handover (Traffic Channel)]+

[Call Drops Due to Loopback Start Failure]+

[Call Drops Due to Failures to Return to Normal Call from Loopback]

Call Drops on Radio Interface in Stable State (Traffic Channel): indicates RF issue. Check coverage at droppoints; check interference in the cell; check for missing neighbours.

Call Drops on Radio Interface in Handover State (Traffic Channel): drops during handover procedure; check

the handover failure counters to get more details for the handover failure cause.


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Call Drops due to No MRs from MS for a Long Time (Traffic Channel): After seizing a TCH, the MS

sends a measurement report to the BSC every 480 ms. If the BSC does not receive any measurement

report within a certain period, call drop occurs on the Um interface. Check UL coverage/UL interference

at drop points. Check for possible MS problem.

Call Drops due to Abis Terrestrial Link Failure (Traffic Channel): indicates Abis transmission problem.

Check relative alarms.

Call Drops due to Equipment Failure (Traffic Channel): indicates BSS hardware or software problem.

Check relative alarms.

Call Drops due to Forced Handover (Traffic Channel): After the MS seizes a traffic channel, the BSC

initiates forced handover in the case of channel preemption, channel failure, or channel blocking. If the

handover of the MS fails, the BSC releases the call. Call Drops Due to Loopback Start Failure: After seizing a channel, the MS starts the local switching. This

measurement provides the number of call drops due to the failure in starting the local switching caused

by different reasons. The cause value can be Terrestrial Resource Request Failure, Failures on the BTS

Side, or Timer Expired.

Call Drops Due to Failures to Return to Normal Call from Loopback: After a call is in the BSC/BTS local

switch state, it incurs a handover. The local switch, however, cannot be continued because the target

cell of the handover may not support local switch, the outgoing BSC handover fails, the TRX that carries

the target channel of the handover may not support local switch, or the specified handover fails. TheBSC attempts to restore the call to a normal one. The restoration may fail due to various reasons. If the

restoration fails, the MS incurs call drop.


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2. Parameters that affect TCH Drop Call Rate:

Check and tune appropriately, if needed, the values of the following parameters:

- RLT: Radio Link Timeout; recommended value: 52

- SAMULFRM: SACCH Multi-Frames; recommended value: 32


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6. High HO fail (1)

- KPI formula:

Handover Success Rate= (([Successful Outgoing Internal Inter-Cell Handover]+[Successful Outgoing

External Inter-Cell Handovers])/([Outgoing Internal Inter-Cell Handover Requests]+[Outgoing External Inter-

Cell Handover Requests]))*{100}

Analysis process:

1.Identify the possible cause of the handover failures by checking the following counters:

A. Internal HO (intra-BSC):

Basic intra-BSC inter-cell handover signalling procedure:


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6. High HO fail (2)

The main causes for a failed outgoing internal inter-cell handover include:

1) Causes related to resource allocation:

- No traffic channel is available.- No speech version is available.

- No Abis resource is available.

- The BSC fails to obtain the terrestrial resources.

2) Causes related to access on the Um interface

- The MS fails to access the new channel and then reconnects to the old channel.

- The timer for the BSC to wait for an HO CMP message expires.

3) Abnormal causes

- The BSC fails to activate the allocated channel.

- A fault occurs on the A interface.


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6. High HO fail (3)

(1) The following counters are measured when the outgoing internal inter-cell handover fails because of

failed allocation of relevant resources.

- H312A:CELL_INTRABSC_OUTCELL_HO_FAIL_CONG : no channel is available in the target cell(congestion)

- H312L: CELL_INTRABSC_OUTCELL_HO_FAIL_NO_IDLE_ABIS: no circuit resource is available on the

Abis interface in the target cell when the Abis dynamic allocation is enabled (congestion on Abis)

- H312H:CELL_INTRABSC_OUTCELL_HO_FAIL_NO_SPEECH_VER : no proper speech version is

available in the target cell; check speech version configuration

- H312B:CELL_INTRABSC_OUTCELL_HO_FAIL_APPLY_TRSL_FAIL : BSC fails to obtain circuit resource

when establishing the terrestrial connection; check A interface circuit status; check A interface alarms


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6. High HO fail (4)

(2) The following counters provide the numbers of failed internal intra-cell handovers when the MS fails to

access the new channel on the Um interface.

In the outgoing internal inter-cell handover procedure, the BSC sends an HO CMD message to the MSthrough the originating cell and initiates a timer (T3103) to wait for a HO CMP message. If the MS

reconnects to the old channel and sends a HO FAIL message on the old channel before the timer expires,

the following counters are measured in the originating cell based on the failure cause value:

- H312Da:CELL_INTRABSC_OUTCELL_HO_FAIL_RECONN_SUCC_MS_RPT_ABNORM_REL_UNS :

Abnormal Release, Unspecified

- H312Db:CELL_INTRABSC_OUTCELL_HO_FAIL_RECONN_SUCC_MS_RPT_ABNORM_REL_CHN :Abnormal Release, Channel Unacceptable

- H312Dc:CELL_INTRABSC_OUTCELL_HO_FAIL_RECONN_SUCC_MS_RPT_ABNORM_REL_EXP :

Abnormal Release, Timer Expired

- H312Dd:CELL_INTRABSC_OUTCELL_HO_FAIL_RECONN_SUCC_MS_RPT_ABNORM_REL_NO_ACT :

Abnormal Release, No Activity on the Radio Path

- H312De:CELL_INTRABSC_OUTCELL_HO_FAIL_RECONN_SUCC_MS_RPT_PREEMPT : Preemptive

Release

- H312Df:CELL_INTRABSC_OUTCELL_HO_FAIL_RECONN_SUCC_MS_RPT_HO_TA : Timing Advanceout of Range

- H312Dg:CELL_INTRABSC_OUTCELL_HO_FAIL_RECONN_SUCC_MS_RPT_CH_MODE : Channel

Mode Unavailable

- H312Dh:CELL_INTRABSC_OUTCELL_HO_FAIL_RECONN_SUCC_MS_RPT_FREQ : Frequency

Unavailable


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For internal use

6. High HO fail (5)

- H312Di:CELL_INTRABSC_OUTCELL_HO_FAIL_RECONN_SUCC_MS_RPT_C_CLR : Call Already

Cleared

- H312Dj:CELL_INTRABSC_OUTCELL_HO_FAIL_RECONN_SUCC_MS_RPT_SEMANT : Semantically

Incorrect Message- H312Dk:CELL_INTRABSC_OUTCELL_HO_FAIL_RECONN_SUCC_MS_RPT_INV_MAN : Invalid

Mandatory Information

- H312Dl:CELL_INTRABSC_OUTCELL_HO_FAIL_RECONN_SUCC_MS_RPT_M_T_NE : Message Type

Non-existent or Not Implemented

- H312Dm:CELL_INTRABSC_OUTCELL_HO_FAIL_RECONN_SUCC_MS_RPT_M_T_NC : Message Type

Not Compatible with Protocol State

- H312Dn:CELL_INTRABSC_OUTCELL_HO_FAIL_RECONN_SUCC_MS_RPT_CONDIT : Conditional IEError

- H312Do:CELL_INTRABSC_OUTCELL_HO_FAIL_RECONN_SUCC_MS_RPT_NO_CA : No Cell Allocation

Available

- H312Dp:CELL_INTRABSC_OUTCELL_HO_FAIL_RECONN_SUCC_MS_RPT_PROTOCL : Protocol Error

Unspecified

- H312Dq:CELL_INTRABSC_OUTCELL_HO_FAIL_RECONN_SUCC_MS_RPT_OTHER : Other Causes


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For internal use

6. High HO fail (6)

During the handover procedure excluding directed retry, after the BSC successfully allocates and activates

the channel in the target cell, it sends an HO CMD message to the MS and starts the timer T3103 to wait for

the HO CMP message. If no HO CMP is received by the BSC before T3103 expires, the BSC releases the

call. Then, the specific one of the following counters is measured in the target cell based on the type of thetarget channel, that is, signalling channel (SDCCH/TCHF/TCCH) or traffic channel (TCHF/TCHH):

- H3120C:CELL_INTRABSC_OUTCELL_HO_FAIL_EXP_SD_NOT_INCLUDE_DR

- H3127Cb:CELL_INTRABSC_OUTCELL_HO_FAIL_EXP_TCHF_SIG_NOT_INCLUDE_DR

- H3128Cb:CELL_INTRABSC_OUTCELL_HO_FAIL_EXP_TCHH_SIG_NOT_INCLUDE_DR

- H3127Ca:CELL_INTRABSC_OUTCELL_HO_FAIL_EXP_TCHF_TRAF_NOT_INCLUDE_DR

- H3128Ca:CELL_INTRABSC_OUTCELL_HO_FAIL_EXP_TCHH_TRAF_NOT_INCLUDE_DR

In directed retry procedure, the BSC sends an HO CMD message to the MS through the originating cell and

starts timer T3103 to wait for an HO CMP message. If no HO CMP is received by the BSC before T8

expires, the following counter is measured:

- H3121C:CELL_INTRABSC_OUTCELL_HO_FAIL_EXP_DR

Note:The counter CH312C:CELL_INTRABSC_OUTCELL_HO_FAIL_EXPis the sum of all the above

counters, i.e. the six counters above are sub-items of this counter.

6 Hi h HO f il ( )


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For internal use

6. High HO fail (7)

(3) The following counters are measured when the outgoing internal inter-cell handover fails because of

equipment faults.

After the BSC successfully performs channel allocation and speech version confirmation in the target cell, itsends a CH ACT message to the BTS for activating the channel, and starts the corresponding timer to wait

for the response. If the BSC receives a CH ACT NACK or no response from the BTS before the timer

expires, the following counter is measured:

- H312I:CELL_INTRABSC_OUTCELL_HO_FAIL_CHACT_FAIL

If an outgoing internal intra-cell handover fails because the BSC locally releases the call after receiving an

SS7 link abnormality indication, the following counter is measured:- H312G:CELL_INTRABSC_OUTCELL_HO_FAIL_A_INTERF_FAIL

6 Hi h HO f il (8)


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For internal use

6. High HO fail (8)

B. External HO (inter-BSC):

Basic inter-BSC inter-cell handover signalling procedure:

The main causes for a failed outgoing

external inter-cell handover include:

1. The timer T7 for the BSC to wait for

a HO CMD message, after having

sent a HO RQD message, expires.

2. The BSC receives a HO RQD

REJ message from the MSC.

3. The MS fails to access the new

channel and then reconnects to theold channel, sending a HO FAIL

message.

4. The timer T8 for the BSC to wait for

a CLEAR CMD message , after

having sent a HO CMD message,

expires.

5. The BSC receives a CLEAR CMD

message from the MSC which

contains a failure handover cause.

6. An SS7 link failure occurs on the A

interface

6 Hi h HO f il (9)


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For internal use

6. High HO fail (9)

(1) During the outgoing external inter-cell handover procedure, timer T7 is started after the BSC sends the

HO RQD to the MSC and waits for the HO CMD command from the MSC. If no HO CMD is received by the

BSC before T7 expires, the BSC re-sends the HO RQD message. The specific counter provides the number

of failed outgoing external inter-cell handovers when the number of resending times has exceeded themaximum configuration.

In the outgoing external inter-cell handover (excluding directed retry) procedure, the following counters are

measured when T7 expires based on the channel type:

- H3320L:CELL_INTERBSC_OUTCELL_HO_FAIL_T7_EXP_SD_NOT_INCLUDE_DR

- H3327Lb:CELL_INTERBSC_OUTCELL_HO_FAIL_T7_EXP_TCHF_SIG

- H3328Lb:CELL_INTERBSC_OUTCELL_HO_FAIL_T7_EXP_TCHH_SIG- H3327La:CELL_INTERBSC_OUTCELL_HO_FAIL_T7_EXP_TCHF_TRAF_CH

- H3328La:CELL_INTERBSC_OUTCELL_HO_FAIL_T7_EXP_TCHH_TRAF_CH

In the outgoing external inter-cell handover (directed retry) procedure, the following counter is measured:

- H3321L:CELL_INTERBSC_OUTCELL_HO_FAIL_T7_EXP_DR

6 Hi h HO f il (10)


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39 Nokia Siemens Networks Presentation / Author / DateFor internal use

6. High HO fail (10)

(2) The following counters provide the number of times that the BSC terminates the outgoing external inter-

cell handover because it receives an HO RQD REJ message from the MSC after sending the HO RQD

message to the MSC.

- H332Ka:CELL_INTERBSC_OUTCELL_HO_REQ_REJ_OM_INTERVENTION: OM Intervention

- H332Kb:CELL_INTERBSC_OUTCELL_HO_REQ_REJ_EQUIP_FAIL : Equipment Failure

- H332Kc:CELL_INTERBSC_OUTCELL_HO_REQ_REJ_NO_RADIO_RES: No Radio Resource Available

- H332Kd:CELL_INTERBSC_OUTCELL_HO_REQ_REJ_REQ_NO_TER_RES: Requested Terrestrial

Resource Unavailable

- H332Ke:CELL_INTERBSC_OUTCELL_HO_REQ_REJ_BSS_NOT_EQUIP: BSS not Equipped

- H332Kf:CELL_INTERBSC_OUTCELL_HO_REQ_REJ_INVALID_CELL : Invalid Cell- H332Kg:CELL_INTERBSC_OUTCELL_HO_REQ_REJ_REQ_TRANS_NO_ADAPT: Requested

Transcoding/Rate Adaption Unavailable

- H332Kh:CELL_INTERBSC_OUTCELL_HO_REQ_REJ_CIRCUIT_POOL_MISMATCH : Circuit Pool

Mismatch

- H332Ki:CELL_INTERBSC_OUTCELL_HO_REQ_REJ_REQ_NO_SV: Requested Speech Version

Unavailable

- H332Kj:CELL_INTERBSC_OUTCELL_HO_REQ_REJ_CIPH_ALG_NOT_SUPPORT: Ciphering Algorithm

not Supported- H332Kk:CELL_INTERBSC_OUTCELL_HO_REQ_REJ_TER_CIR_ALLOC: Terrestrial Circuit Already

Allocated

- H332Kl:CELL_INTERBSC_OUTCELL_HO_REQ_REJ_INVALID_MSG : Invalid Message

- H332Km:CELL_INTERBSC_OUTCELL_HO_REQ_REJ_PROTOCOL_ERR : Protocol Error between BSS

and MSC

- H332Kn:CELL_INTERBSC_OUTCELL_HO_REQ_REJ_OTHER: Other Causes

6 Hi h HO f il (11)


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(3) In the outgoing external inter-cell handover procedure, the BSC sends a HO CMD message to the MS

through the originating cell and initiates timer T8 to wait for a CLEAR CMD message from the MSC which

will indicate Successful Handover. If the MS reconnects to the old channel and sends an HO FAIL message

on the old channel before T8 expires, the specific one of the following counters is measured in the target cellbased on the cause value in the HO FAIL message.

- H332Da:CELL_INTERBSC_OUTCELL_HO_FAIL_RECONN_SUCC_MS_RPT_ABNORM_REL_UNS :

Abnormal Release, Unspecified

- H332Db:CELL_INTERBSC_OUTCELL_HO_FAIL_RECONN_SUCC_MS_RPT_ABNORM_REL_CHN :

Abnormal Release, Channel Unacceptable

- H332Dc:CELL_INTERBSC_OUTCELL_HO_FAIL_RECONN_SUCC_MS_RPT_ABNORM_REL_EXP :Abnormal Release, Timer Expired

- H332Dd:CELL_INTERBSC_OUTCELL_HO_FAIL_RECONN_SUCC_MS_RPT_ABNORM_REL_NO_ACT :

No Activity on the Radio Path

- H332De:CELL_INTERBSC_OUTCELL_HO_FAIL_RECONN_SUCC_MS_RPT_PREEMPT : Preemptive

Release

- H332Df:CELL_INTERBSC_OUTCELL_HO_FAIL_RECONN_SUCC_MS_RPT_HO_TA : Timing Advance

out of Range

- H332Dg:CELL_INTERBSC_OUTCELL_HO_FAIL_RECONN_SUCC_MS_RPT_CH_MODE : ChannelMode Unavailable

- H332Dh:CELL_INTERBSC_OUTCELL_HO_FAIL_RECONN_SUCC_MS_RPT_FREQ : Frequency

Unavailable

- H332Di:CELL_INTERBSC_OUTCELL_HO_FAIL_RECONN_SUCC_MS_RPT_CALL_CLR : Call Already

Cleared

6 Hi h HO f il (12)


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- H332Dj:CELL_INTERBSC_OUTCELL_HO_FAIL_RECONN_SUCC_MS_RPT_SEMANT : Semantically

Incorrect Message

- H332Dk:CELL_INTERBSC_OUTCELL_HO_FAIL_RECONN_SUCC_MS_RPT_INVALID_MAN : Invalid

Mandatory Information- H332Dl:CELL_INTERBSC_OUTCELL_HO_FAIL_RECONN_SUCC_MS_RPT_MSG_TYPE_NEXISTENT :

Message Type Non-existent or Not Implemented

- H332Dm:CELL_INTERBSC_OUTCELL_HO_FAIL_RECONN_SUCC_MS_RPT_MSG_TYPE_NOT_CO

MPATIBLE: Message Type Not Compatible with Protocol State

- H332Dn:CELL_INTERBSC_OUTCELL_HO_FAIL_RECONN_SUCC_MS_RPT_CONDIT : Conditional IE

Error

- H332Do:CELL_INTERBSC_OUTCELL_HO_FAIL_RECONN_SUCC_MS_RPT_NO_CA : No Cell AllocationAvailable

- H332Dp:CELL_INTERBSC_OUTCELL_HO_FAIL_RECONN_SUCC_MS_RPT_PROTOCL : Protocol Error

Unspecified

- H332Dq:CELL_INTERBSC_OUTCELL_HO_FAIL_RECONN_SUCC_MS_RPT_OTHER : Other Causes

6 Hi h HO f il (13)


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(4) In the outgoing external inter-cell handover procedure, after sending the HO CMD message to the MS,

the BSC starts the timer T8 to wait for the CLEAR CMD message from the MSC. The specific counter

provides the number of times that the BSC terminates the handover due to the expiration of T8.

In the outgoing external inter-cell handover (excluding directed retry) procedure, the following counters are

measured when T8 expires based on the channel type:

- H3320C:CELL_INTERBSC_OUTCELL_HO_FAIL_T8_EXP_SD_NOT_INCLUDE_DR

- H3327Cb:CELL_INTERBSC_OUTCELL_HO_FAIL_T8_EXP_TCHF_SIG

- H3328Cb:CELL_INTERBSC_OUTCELL_HO_FAIL_T8_EXP_TCHH_SIG

- H3327Ca:CELL_INTERBSC_OUTCELL_HO_FAIL_T8_EXP_TCHF_TRAF_CH

- H3328Ca:CELL_INTERBSC_OUTCELL_HO_FAIL_T8_EXP_TCHH_TRAF_CH

In the outgoing external inter-cell handover (directed retry) procedure, the following counter is measured:

- H3321C:CELL_INTERBSC_OUTCELL_HO_FAIL_T8_EXP_DR

Note:The counter CH332C:CELL_INTERBSC_OUTCELL_HO_FAIL_T8_EXPis the sum of all the above

counters, i.e. the six counters above are sub-items of this counter.

6 Hi h HO f il (14)


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(5) The following counters provides the number of times that the BSC terminates the outgoing external inter-

cell handover because the BSC receives a CLEAR CMD message from the MSC and the cause value

carried in the message is not Handover successful.

- H332Ha:CELL_INTERBSC_OUTCELL_HO_FAIL_MSC_CLR_RADIO_INTF_MSG_FAIL : Radio Interface

Message Failure

- H332Hb:CELL_INTERBSC_OUTCELL_HO_FAIL_MSC_CLR_RADIO_INTF_FAIL : Radio Interface Failure

- H332Hc:CELL_INTERBSC_OUTCELL_HO_FAIL_MSC_CLR_OM_INTERVENTION : OM Intervention

- H332Hd:CELL_INTERBSC_OUTCELL_HO_FAIL_MSC_CLR_EQUIP_FAIL : Equipment Failure

- H332He:CELL_INTERBSC_OUTCELL_HO_FAIL_MSC_CLR_PREEMPTION : Preemption

- H332Hf:CELL_INTERBSC_OUTCELL_HO_FAIL_MSC_CLR_INVALID_MSG : Invalid Message- H332Hg:CELL_INTERBSC_OUTCELL_HO_FAIL_MSC_CLR_PROTOCOL_ERR : Protocol Error between

BSS and MSC

- H332Hh:CELL_INTERBSC_OUTCELL_HO_FAIL_MSC_CLR_OTHER : Other Causes

(6) The following counter provides the number of failed outgoing external inter-cell handovers when the BSC

detects an SS7 link failure on the A interface and releases the call:

- H332G:CELL_INTERBSC_OUTCELL_HO_FAIL_MSC_CLR_A_INTF_FAIL

6 High HO fail (15)


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2. Check interference in source and target cells. High interference can cause handover failure.

3. Check whether ping-pong handover occurs due to no dominant server in the area. Ping-pong may lead

to HO failures.

4. Parameters that affect HO Success Rate:

- T3103A: Timer started after the BSC delivers a HANDOVER COMMAND in an intra-BSC inter-cell

handover. If the BSC receives a HANDOVER COMPLETE message before this timer expires, the timer

stops. If this timer expires, the BSC considers the handover as failed. Recommended value: 10000 ms

- T7: Timer is started after the BSC sends the HO RQD to the MSC and waits for the HO CMD command

from the MSC in an inter-BSC inter-cell handover procedure. Recommended value: 10000 ms

- T8: After sending the HO CMD message to the MS, the BSC starts this timer to wait for the CLEAR CMD

message from the MSC in an inter-BSC inter-cell handover procedure. Recommended value: 10000 ms

7 Low Coverage (1)


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7. Low Coverage (1)

1. TA measurements vs. cell radius

The following counters provide TA distribution per TRX in the cell. The measurements can be checked

versus cell radius to identify possible coverage problems.

- S4400A:TRX_MR_NUM_BY_TA_0





- S4405A:TRX_MR_NUM_BY_TA_5- S4406A:TRX_MR_NUM_BY_TA_6






















- S4430A:TRX_MR_NUM_BY_TA_30_TO_31



- S4436A:TRX_MR_NUM_BY_TA_36_TO_37- S4438A:TRX_MR_NUM_BY_TA_38_TO_39





- S4463A:TRX_MR_NUM_BY_TA_GT_63

7 Low Coverage (2)


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7. Low Coverage (2)

2. Rxlevel & Rxquality measurements

BSC receives reports that contain the uplink and downlink receive level rank and the uplink and downlink

receive quality rank.- The receive level ranges from rank 0 to rank 7. Each rank corresponds to a receive level range.

- The receive quality ranges from rank 0 to rank 7. Each rank corresponds to a bit error rate range.

Receive Level Measurement, together with Receive Quality Measurement per TRX, reflects the radio signal

coverage and interference of a cell. For example, a high ratio of high level and low quality suggests possible

interference; a high ratio of low level and low quality suggests poor coverage.

Receive Level Rank Receive Level (dBm)

0 -100

1 (-100,-95]2 (-95,-90]

3 (-90,-85]

4 (-85,-80]

5 (-80,-75]

6 (-75,-70]

7 > -70

Receive Quality Rank Bit Error Rate

0 < 0.2%

1 0.2%-0.4%2 0.4 %-0.8%

3 0.8%-1.6%

4 1.6%-3.2%

5 3.2%-6.4%

6 6.4%-12.8%

7 > 12.8%

7 Low Coverage (3)


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7. Low Coverage (3)

TCHF Receive Level Measurement per TRX provides the number of measurement reports from the

TCHF that contain receive level rank and receive quality rank. TCHF receive level and quality measurements

for UL and DL are given by following counters:

- S4100A:TRX_FR_UP_LEV_0_RX_QLTY_0



...

Saaaaa:TRX_FR_UP_LEV_x_RX_QLTY_y

where: aaaaa=counter ID, x=receive level rank (0~7), y=receive quality rank (0~7)

TCHH Receive Level Measurement per TRX refers to the measurement of the sampled receive level

ranks and receive quality ranks in the MRs on the TCHH. TCHH receive level and quality measurements for

UL and DL are given by following counters:

- S4100C:TRX_HR_UP_LEV_0_RX_QLTY_0

- S4101C:TRX_HR_UP_LEV_0_RX_QLTY_1- S4102C:TRX_HR_UP_LEV_0_RX_QLTY_2

Saaaaa:TRX_HR_UP_LEV_x_RX_QLTY_y

where: aaaaa=counter ID, x=receive level rank (0~7), y=receive quality rank (0~7)

- S4100B:TRX_FR_DOWN_LEV_0_RX_QLTY_0



..


- S4100D:TRX_HR_DOWN_LEV_0_RX_QLTY_0

- S4101D:TRX_HR_DOWN_LEV_0_RX_QLTY_1- S4102D:TRX_HR_DOWN_LEV_0_RX_QLTY_2


8 High Interference (1)


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8. High Interference (1)

1. Idle UL Interference

The interference band is the uplink interference level of a channel reported by the BTS to the BSC in the RF

RESOURCE INDICATION message when the channel is idle. There are five levels of interferencebands. The threshold of each interference band can be configured:

Higher rank suggests higher interference level.

Parameter ID Interference Band Recommended Value (dBm)

INTERFTHRES1 1 -105

INTERFTHRES2 2 -98

INTERFTHRES3 3 -92INTERFTHRES4 4 -87

INTERFTHRES5 5 -85

8 High Interference (2)


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8. High Interference (2)

The following counters provide the average number of idle channels (TCHF, TCHH, or SDCCH) whose

interference level are in each interference band (1-5) per granularity period.

-AS4200A:TRX_CH_IN_INTFR1_AVR_NUM_SD-AS4200B:TRX_CH_IN_INTFR2_AVR_NUM_SD

-AS4200C:TRX_CH_IN_INTFR3_AVR_NUM_SD

-AS4200D:TRX_CH_IN_INTFR4_AVR_NUM_SD

-AS4200E:TRX_CH_IN_INTFR5_AVR_NUM_SD

-AS4207A:TRX_CH_IN_INTFR1_AVR_NUM_FR

-AS4207B:TRX_CH_IN_INTFR2_AVR_NUM_FR

-AS4207C:TRX_CH_IN_INTFR3_AVR_NUM_FR-AS4207D:TRX_CH_IN_INTFR4_AVR_NUM_FR

-AS4207E:TRX_CH_IN_INTFR5_AVR_NUM_FR

-AS4208A:TRX_CH_IN_INTFR1_AVR_NUM_HR

-AS4208B:TRX_CH_IN_INTFR2_AVR_NUM_HR

-AS4208C:TRX_CH_IN_INTFR3_AVR_NUM_HR

-AS4208D:TRX_CH_IN_INTFR4_AVR_NUM_HR

-AS4208E:TRX_CH_IN_INTFR5_AVR_NUM_HR

2. Rxlevel & Quality distributions can be used to identify interference in a cell. Refer to Case 7 of present

document for details.

3. TA measurements can be used to identify interference in a cell. Refer to Case 7 of present document for

details.

9 High Signalling Failures Before TBF Establishment (1)


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9. High Signalling Failures Before TBF Establishment (1)

- KPI formula:

Success Rate of Random Access (Packet Service)=

[A301H:CELL_IMM_ASS_CMD_PS]/[A300H:CELL_CH_REQ_PACKET_CALL]

AGCH Blocking= ([L3188A:CELL_DEL_IND]/[Channel Requests (all reasons)])*{100}

Paging Overload Rate PS= ([PACKET CCCH LOAD IND Messages Sent on Abis Interface])/([Delivered

Paging Messages for PS Service])*{100}

Analysis process:

1.High signalling failures before TBF establishment refers to failures on the CCCH. During one-phaseaccess or two-phase access on the CCCH, the MS fails to proceed to TBF establishment process due to

failures on the CCCH channel: AGCH or PCH. The failures most likely will be due to CCCH congestion.

2.Check the above KPIs to identify congestion on the AGCH or PCH.

3.Check relative alarms on the BSC/BTS in order to locate any hardware/software fault.

4.If blocking is the problem, proceed to the following steps in order to relieve congestion on the CCCH.

Note:For more details on CCCH capacity optimisation refer to HUA_2G_Capacity_Optimization_v1.0.ppt

document from Multivendor team in IMS.



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5. Check the values of following parameters:

- BSAGBLKSRES: Blocks Reserved for AGCH. Value range: 0-7. Recommended: 2

- BSPAMFRAMS: Multi-Frames in a Cycle on the Paging CH. Value range: 2-9. Value depends on

paging load. Increase value when paging load increases. Value should be kept as small as possible.- PAGTIMES: Paging Times. Value range: 1-8 (For the BTS, this parameter is used to determine paging

retransmissions. This parameter and the number of paging times configured in the MSC determine the

number of paging retransmissions.)

6. Check if Flow Control feature is enabled. Recommendation is that Flow Control is always enabled. Flow

Control, controls the arrival of paging messages on the A interface (MSC-BSC) and on the LAPD links

(BSC-BTS).

7. Check volume of PS pagings (A331:CELL_PAGES_PS: Delivered Paging Messages for PS Service). If

too high then check if PCCCH is configured. If PCCCH is configured then packet pages can be

transmitted through PPCH, thus reducing PCH load.

CS pages can also be transmitted through packet control channels (PACCH or PPCH). For this to work,

Gs interface needs to be configured between SGSN-MSC. Also Network Mode of Operation should be

set to 1.

- NMO: Network Operation Mode

8. Check Location Area: re-size might be required (make smaller).

9. Consider splitting cells in the paging overload area. This will grow CCCH capacity.

10. Add CCCH capacity (Extended BCCH).



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Packet access on the CCCH signalling procedure:

Fig.1 One-phase packet access on the uplink CCCH Fig.2 Two-phase packet access on the uplink CCCH

MS BSCBTS

Channel Request

Immediate Assignment

RLC data block(with TLLI)

Packet Uplink Ack/Nack(with TLLI)

RLC data block(without TLLI)


Packet Uplink Ack/Nack(without TLLI)


MS BSCBTS

Channel Request

Immediate Assignment

Packet Resource Request(with TLLI)

Packet Uplink Assignment(with TLLI)

RLC data block

RLC data block

Packet Uplink Ack/Nack

RLC data block

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10. High TBF Establishment Failures (1)

- KPI formula:

Uplink Assignment Success Rate= (([Number of Successful Uplink GPRS TBF Establishments]+[Number of

Successful Uplink EGPRS TBF Establishments])/([Number of Uplink GPRS TBF Establishment

Attempts]+[Number of Uplink EGPRS TBF Establishment Attempts]))*{100}

Downlink Assignment Success Rate= (([Number of Successful Downlink GPRS TBF

Establishments]+[Number of Successful Downlink EGPRS TBF Establishments])/([Number of Downlink

GPRS TBF Establishment Attempts]+[Number of Downlink EGPRS TBF Establishment Attempts]))*{100}

Analysis process:1.Identify the possible cause of the TBF establishment failures by checking the following counters:

A. UL GPRS TBF establishment failures:

-A9003:UP_GPRS_TBF_ESTB_FAIL_NO_CHAN_RES: number of failed uplink GPRS TBF establishments

due to no channel available. Indicates congestion on the TCH; refer to Case 4 of present document for

handling suggestions.

-A9004:UP_GPRS_TBF_ESTB_FAIL_MS_NO_RESP: number of failed uplink GPRS TBF establishments

due to no response from MS. Indicates bad RF conditions in the cell. Check cell coverage and interference.-A9037:UP_GPRS_TBF_ESTB_FAIL_SEND_ASSMSG_FAIL: In dedicated mode, the BSS sends the

resource assignment command to the MS over the DCCH if both the network and the MS support DTM

(Dual Transfer Modesimultaneous support of CS+PS service). If the resource assignment command is not

sent successfully and the establishment of the uplink GPRS TBF thus fails, this counter is incremented by

one.



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10. High TBF Establishment Failures (2)-A9038:UP_GPRS_TBF_ESTB_FAIL_MS_RESP_ASS_FAILURE: In dedicated mode, the BSS sends the

resource assignment command to the MS over the DCCH if both the network and the MS support DTM

(Dual Transfer Modesimultaneous support of CS+PS service). If the MS responds with the resource

assignment failure message and the establishment of the uplink GPRS TBF thus fails, this counter is

incremented by one.-A9016:UP_GPRS_TBF_ESTB_FAIL_OTHER_CAUSE: This measurement provides the number of failed

uplink GPRS TBF establishments due to other causes in a granularity period. This may happen because an

exception or failure occurs in the resource assignment or the overload protection (flow control) is triggered.

Check BSS alarms in order to locate possible faults in the equipment (h/w or s/w).

B. UL EGPRS TBF establishment failures:

-A9203:UP_EGPRS_TBF_ESTB_FAIL_NO_CHAN_RES: number of failed uplink EGPRS TBFestablishments due to no channel available. Indicates congestion on the TCH; refer to Case 4 of present

document for handling suggestions.

-A9204:UP_EGPRS_TBF_ESTB_FAIL_MS_NO_RESP: number of failed uplink EGPRS TBF

establishments due to no response from MS. Indicates bad RF conditions in the cell. Check cell coverage

and interference.

-A9235:UP_EGPRS_TBF_ESTB_FAIL_SEND_ASSMSG_FAIL: In dedicated mode, the BSS sends the

resource assignment command to the MS over the DCCH if both the network and the MS support DTM. If

the resource assignment command is not sent successfully and the establishment of the uplink EGPRS TBFthus fails, this counter is incremented by one.

-A9236:UP_EGPRS_TBF_ESTB_FAIL_MS_RESP_ASS_FAILURE: In dedicated mode, the BSS sends the


the MS responds with the resource assignment failure message and the establishment of the uplink EGPRS

TBF thus fails, this counter is incremented by one.



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-A9216:UP_EGPRS_TBF_ESTB_FAIL_OTHER_CAUSE: This measurement provides the number of failed

uplink EGPRS TBF establishments due to other causes in a granularity period. This may happen because an

exception or failure occurs in the resource assignment or the overload protection (flow control) is triggered.

Check BSS alarms in order to locate possible faults in the equipment (h/w or s/w).

C. DL GPRS TBF establishment failures:

-A9103:DOWN_GPRS_TBF_ESTB_FAIL_NO_CHAN_RES: number of failed downlink GPRS TBF

establishments due to no channel available. Indicates congestion on the TCH; refer to Case 4 of present

document for handling suggestions.

-A9104:DOWN_GPRS_TBF_ESTB_FAIL_MS_NO_RESP: number of failed downlink GPRS TBF


and interference.

-A9135:DOWN_GPRS_TBF_ESTB_FAIL_SEND_ASSMSG_FAIL: In dedicated mode, the BSS sends the


the resource assignment command is not sent successfully and the establishment of the downlink GPRS


-A9136:DOWN_GPRS_TBF_ESTB_FAIL_MS_RESP_ASS_FAILURE: In dedicated mode, the BSS sends

the resource assignment command to the MS over the DCCH if both the network and the MS support DTM.

If the MS responds with the resource assignment failure message and the establishment of the downlinkGPRS TBF thus fails, this counter is incremented by one.

-A9115:DOWN_GPRS_TBF_ESTB_FAIL_OTHER_CAUSE: This measurement provides the number of

failed downlink GPRS TBF establishments due to other causes in a granularity period. This may happen

because an exception or failure occurs in the resource assignment or the overload protection (flow control) is

triggered. Check BSS alarms in order to locate possible faults in the equipment (h/w or s/w).



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D. DL EGPRS TBF establishment failures:

-A9303:DOWN_EGPRS_TBF_ESTB_FAIL_NO_CHAN_RES: number of failed downlink EGPRS TBF

establishments due to no channel available. Indicates congestion on the TCH; refer to Case 4 of present

document for handling suggestions.-A9304:DOWN_EGPRS_TBF_ESTB_FAIL_MS_NO_RESP: number of failed downlink EGPRS TBF


and interference.

-A9333:DOWN_EGPRS_TBF_ESTB_FAIL_SEND_ASSMSG_FAIL: In dedicated mode, the BSS sends the


the resource assignment command is not sent successfully and the establishment of the downlink EGPRS


-A9334:DOWN_EGPRS_TBF_ESTB_FAIL_MS_RESP_ASS_FAILURE: In dedicated mode, the BSS sends

the resource assignment command to the MS over the DCCH if both the network and the MS support DTM.

If the MS responds with the resource assignment failure message and the establishment of the downlink

EGPRS TBF thus fails, this counter is incremented by one.

-A9315:DOWN_EGPRS_TBF_ESTB_FAIL_OTHER_CAUSE: This measurement provides the number of

failed downlink EGPRS TBF establishments due to other causes in a granularity period. This may happen

because an exception or failure occurs in the resource assignment or the overload protection (flow control) is

triggered. Check BSS alarms in order to locate possible faults in the equipment (h/w or s/w).



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Summary of corrective actions:

1. If TBF establishment failure is due to congestion in TCH, refer to Case 4 of present document for handling

suggestions. In brief:- Check availability of current and neighbouring sites in order to make sure that TCH congestion is not due to

unavailability issues.

- Check FR/HR parameterization (including AMR if enabled in the network). Check usage of HR resources.

- Check Load balancing configuration between cells.

- Add TRX.

2. If TBF establishment failure is due to poor RF quality, then:

- Check cell coverage and interference. Refer to Cases 7, 8 of present document for more details on how to

check signal strength and quality in Huawei 2G system.

- Adjust antenna parameters (tilt, azimuth) to improve coverage and/or suppress interference in the

problematic areas.

- Check antenna line (feeders, jumpers) to identify faulty connections.

- Check BTS hardware (relative alarms) to identify faulty TRXs.

3. If TBF establishment failure is due to equipment fault, check relative BSS alarms (hardware and softwarealarms) in order to identify the faulty part. Repair or replace the faulty equipment once found.

11 High TBF Drops (1)


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11. High TBF Drops (1)

- KPI formula:

Uplink GPRS TBF Drop Rate= (([Number of Uplink GPRS TBF Abnormal Releases due to N3101 Overflow

(MS No Response)]+[Number of Uplink GPRS TBF Abnormal Releases due to N3103 Overflow (MS No

Response)])/[Number of Successful Uplink GPRS TBF Establishments])*{100}

Uplink EGPRS TBF Drop Rate= (([Number of Uplink EGPRS TBF Abnormal Releases due to N3101

Overflow (MS No Response)]+[Number of Uplink EGPRS TBF Abnormal Releases due to N3103 Overflow

(MS No Response)])/[Number of Successful Uplink EGPRS TBF Establishment])*{100}

Downlink GPRS TBF Drop Rate= ([Number of Downlink GPRS intermit transfers]/[Number of Successful

Downlink GPRS TBF Establishments])*{100}

Downlink EGPRS TBF Drop Rate= ([Number of Downlink EGPRS intermit transfers]/[Number of Successful

Downlink EGPRS TBF Establishments])*{100}

Analysis process:

1.Identify the possible cause of the TBF drops by checking the following counters:

A. UL GPRS TBF Drops:-A9006:UP_GPRS_TBF_ABNORM_REL_N3101_OVERFLOW: Number of Uplink GPRS TBF Abnormal

Releases due to N3101 Overflow (MS No Response). Indicates poor radio conditions in the cell. Check

signal level, signal quality and interference in the cell.

-A9007:UP_GPRS_TBF_ABNORM_REL_N3103_OVERFLOW: Number of Uplink GPRS TBF Abnormal



11 High TBF Drops (2)


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Additional UL GPRS TBF abnormal releases:

-A9008:UP_GPRS_TBF_ABNORM_REL_SUSPEND: number of uplink GPRS TBF abnormal releases due

to cell suspension. This may happen because the MS often initiates CS services during the process of PS

services. Another possible cause is that the cell is on the edge of the network location area and therefore thelocation update of the MS is frequent.

-A9009:UP_GPRS_TBF_ABNORM_REL_FLUSH: number of uplink GPRS TBF abnormal releases due to

cell flush. This may happen because the cell reselection procedure is frequently initiated by the MS.

-A9010:UP_GPRS_TBF_ABNORM_REL_NO_CHAN_RES: number of uplink GPRS TBF abnormal

releases due to no channel. Indicates that the channel malfunction is frequent or the channel is blocked

manually. Also indicates congestion on the traffic channel. To guarantee stable PS service in a cell with

heavy CS traffic, add fixed packet channels.

-A9017:UP_GPRS_TBF_ABNORM_REL_CHAN_PREEMPT: number of uplink GPRS TBF abnormal

releases due to channel preemption. Preemption may happen because congestion occurs on the Abis

interface or the dynamic PDCHs in use are occupied by the CS services. Check relative alarms to locate the

cause.

-A9018:UP_GPRS_TBF_ABNORM_REL_OTHER_CAUSE: number of uplink GPRS TBF abnormal

releases due to other causes. This may happen because of incorrect parameters or the number of uplink

GPRS TBFs on the PDCH reaches the limit or the cell is manually blocked. Check relative alarms to locate

the cause.-A9034: UP_GPRS_TBF_ABNORM_REL_EGPRS_TBF_CONNECT: number of abnormal uplink GPRS

TBF releases due to the access of the EGPRS service.

-A9039:UP_GPRS_TBF_ABNORM_REL_CS_HO: number of uplink GPRS TBF abnormal releases due to

CS handover.



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B. UL EGPRS TBF Drops:

-A9206:UP_EGPRS_TBF_ABNORM_REL_N3101_OVERFLOW: Number of Uplink EGPRS TBF Abnormal


signal level, signal quality and interference in the cell.-A9207: UP_EGPRS_TBF_ABNORM_REL_N3103_OVERFLOW: Number of Uplink EGPRS TBF Abnormal



Additional UL EGPRS TBF abnormal releases:

-A9208:UP_EGPRS_TBF_ABNORM_REL_SUSPEND: number of uplink EGPRS TBF abnormal releases

due to cell suspension. This may happen because the MS often initiates CS services during the process of

PS services. Another possible cause is that the cell is on the edge of the network location area and therefore

the location update of the MS is frequent.

-A9209:UP_EGPRS_TBF_ABNORM_REL_FLUSH: number of uplink EGPRS TBF abnormal releases due

to cell flush. This may happen because the cell reselection procedure is frequently initiated by the MS.

Check and tune if necessary cell reselection parameters in the area.

-A9210:UP_EGPRS_TBF_ABNORM_REL_NO_CHAN_RES: number of uplink EGPRS TBF abnormal


manually. Also indicates congestion on the traffic channel. To guarantee stable PS service in a cell withheavy CS traffic, add fixed packet channels.

-A9217:UP_EGPRS_TBF_ABNORM_REL_CHAN_PREEMPT: number of uplink EGPRS TBF abnormal



cause.



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-A9218:UP_EGPRS_TBF_ABNORM_REL_OTHER_CAUSE: number of uplink EGPRS TBF abnormal

releases due to other causes. This may happen because of incorrect parameters or flow control or the cell is

manually blocked. Check relative alarms to locate the cause.

-A9237:UP_EGPRS_TBF_ABNORM_REL_CS_HO: number of uplink EGPRS TBF abnormal releases dueto CS handover.

C. DL GPRS TBF Drops:

-A9118:DOWN_GPRS_TRANS_INTERRUPT_TIMES: number of intermitted downlink GPRS TBF transfers

in a granularity period. The counter is incremented because the downlink PDU buffer is emptied upon

abnormal downlink GPRS TBF releases due to SUSPEND, FLUSH, or failed downlink re-establishments due

to other causes.

-A9106:DOWN_GPRS_TBF_ABNORM_REL_N3105_OVERFLOW: number of downlink GPRS TBF

abnormal releases due to N3105 overflow. Indicates bad radio conditions in the cell. Check coverage and

interference in the cell.

-A9107:DOWN_GPRS_TBF_ABNORM_REL_SUSPEND: number of downlink GPRS TBF abnormal

releases due to cell suspension. This may happen because the MS often initiates CS services during the

process of PS services. Another possible cause is that the cell is on the edge of the network location area

and therefore the location update of the MS is frequent.-A9108:DOWN_GPRS_TBF_ABNORM_REL_FLUSH: number of downlink GPRS TBF abnormal releases

due to cell flush. This may happen because the cell reselection procedure is frequently initiated by the MS.

Check and tune if necessary cell reselection parameters in the area.

-A9109:DOWN_GPRS_TBF_ABNORM_REL_NO_CHAN_RES: number of downlink GPRS TBF abnormal


manually. Also indicates congestion on the traffic channel. To guarantee stable PS service in a cell with

heavy CS traffic, add fixed packet channels.



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-A9116:DOWN_GPRS_TBF_ABNORM_REL_CHAN_PREEMPT: number of downlink GPRS TBF abnormal



cause.-A9117:DOWN_GPRS_TBF_ABNORM_REL_OTHER_CAUSE: number of downlink GPRS TBF abnormal

releases due to other causes. This may happen because of incorrect parameters or the number of uplink

GPRS TBFs on the PDCH reaches the limit or the cell is manually blocked. Check relative alarms to locate

the cause.

-A9132:DOWN_GPRS_TBF_ABNORM_REL_EGPRS_TBF_CONNECT: number of abnormal downlink

GPRS TBF releases due to the access of the EGPRS service.

-A9137:DOWN_GPRS_TBF_ABNORM_REL_CS_HO: number of downlink GPRS TBF abnormal releases

due to CS handover.

D. DL EGPRS TBF Drops:

-A9318:DOWN_EGPRS_TRANS_INTERRUPT_TIMES: number of intermitted downlink EGPRS TBF

transfers in a granularity period. The counter is incremented because the downlink PDU buffer is emptied

upon abnormal downlink GPRS TBF releases due to SUSPEND, FLUSH, or failed downlink re-

establishments due to other causes.

-A9306:DOWN_EGPRS_TBF_ABNORM_REL_N3105_OVERFLOW: number of downlink EGPRS TBF

abnormal releases due to N3105 overflow. Indicates bad radio conditions in the cell. Check coverage and

interference in the cell.

-A9307:DOWN_EGPRS_TBF_ABNORM_REL_SUSPEND: number of downlink EGPRS TBF abnormal

releases due to cell suspension. This may happen because the MS often initiates CS services during the

process of PS services. Another possible cause is that the cell is on the edge of the network location area

and therefore the location update of the MS is frequent.



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-A9308:DOWN_EGPRS_TBF_ABNORM_REL_FLUSH: number of downlink EGPRS TBF abnormal

releases due to cell flush. This may happen because the cell reselection procedure is frequently initiated by

the MS. Check and tune if necessary cell reselection parameters in the area.

-A9309:DOWN_EGPRS_TBF_ABNORM_REL_NO_CHAN_RES: number of downlink EGPRS TBFabnormal releases due to no channel. Indicates that the channel malfunction is frequent or the channel is

blocked manually. Also indicates congestion on the traffic channel. To guarantee stable PS service in a cell

with heavy CS traffic, add fixed packet channels.

-A9316:DOWN_EGPRS_TBF_ABNORM_REL_CHAN_PREEMPT: number of downlink EGPRS TBF

abnormal releases due to channel preemption. Preemption may happen because congestion occurs on the

Abis interface or the dynamic PDCHs in use are occupied by the CS services. Check relative alarms to

locate the cause.

-A9317:DOWN_EGPRS_TBF_ABNORM_REL_OTHER_CAUSE: number of downlink EGPRS TBF

abnormal releases due to other causes. This may happen because of incorrect parameters or overload

protection (flow control) or the cell is manually blocked. Check relative alarms to locate the cause.

-A9335:DOWN_EGPRS_TBF_ABNORM_REL_CS_HO: number of downlink EGPRS TBF abnormal

releases due to CS handover.

12. Low Throughput (1)


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- KPI formula:

A. Average cell throughput:

Average Throughput of Uplink GPRS RLC (kbit/s)=([Total Number of Uplink RLC Data Blocks Using CS1]*{23}+

[Total Number of Uplink RLC Data Blocks Using CS2]*{34}+

[Total Number of Uplink RLC Data Blocks Using CS3]*{40}+

[Total Number of Uplink RLC Data Blocks UsingCS4]*{54})*{8}/({1000}*[Total time of Uplink GPRS TBFs

exist period])

Average Throughput of Downlink GPRS RLC (kbit/s) =([Total Number of Downlink RLC Data Blocks Using CS1]*{23}+

[Total Number of Downlink RLC Data Blocks Using CS2]*{34}+

[Total Number of Downlink RLC Data Blocks Using CS3]*{40}+

[Total Number of Downlink RLC Data Blocks Using CS4]*{54})*{8}/({1000}*[Total time of Downlink GPRS

TBFs exist period])



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o oug put ( )

Average Throughput of uplink EGPRS RLC (kbit/s)=

([Total Number of Uplink EGPRS MCS1 RLC Data Blocks]*{22}+

[Total Number of Uplink EGPRS MCS2 RLC Data Blocks]*{28}+

[Total Number of Uplink EGPRS MCS3 RLC Data Blocks]*{37}+[Total Number of Uplink EGPRS MCS4 RLC Data Blocks]*{44}+





[Total Number of Uplink EGPRS MCS9 RLC Data Blocks]*{74})*{8}/({1000}*[Total time of Uplink EGPRS

TBFs exist period])

Average Throughput of Downlink EGPRS RLC (kbit/s)=

([Total Number of Downlink EGPRS MCS1 RLC Data Blocks]*{22}+

[Total Number of Downlink EGPRS MCS2 RLC Data Blocks]*{28}+




[Total Number of Downlink EGPRS MCS6 RLC data blocks]*{74}+[Total Number of Downlink EGPRS MCS7 RLC Data Blocks]*{56}+


[Total Number of Downlink EGPRS MCS9 RLC Data Blocks]*{74})*{8}/({1000}*[Total time of Downlink

EGPRS TBFs exist period])



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g p ( )

B. Average throughput per TBF:

Average Throughput of Uplink GPRS TBF (kbit/s)= [Average Payload of Single Uplink GPRS TBF

(KB)]*{1024}*{8}/[Average Duration of Uplink GPRS TBF (s)]

Average Throughput of Uplink EGPRS TBF (kbit/s)= [Average Payload of Single Uplink EGPRS TBF

(KB)]*{1024}*{8}/[Average Duration of Uplink EGPRS TBF (s)]

Average Throughput of Downlink GPRS TBF (kbit/s)= [Average Payload of Single Downlink GPRS TBF

(KB)]*{1024}*{8}/[Average Duration of Downlink GPRS TBF (s)]

Average Throughput of Downlink EGPRS TBF (kbit/s)= [Average Payload of Single Downlink EGPRS TBF

(KB)]*{1024}*{8}/[Average Duration of Downlink EGPRS TBF (s)]

Analysis process:

1.Low throughput may be due to problems across the packet service transmission path. Thorough checks

should be done in Gb, Abis, Um interfaces. Also in SGSN, PCU, BSC systems.

2.Gb interface:- Check usage of Gb links. Expand Gb capacity if congestion appears.

Gb usage can be checked through Real Time Monitoring function of BSC LMT: On the Trace & Monitortab

page, choose Monitor> Monitor GPRS Flux.

Also Gb utilization can be checked through following counters:

- RL9608:BC_TRAN_UP_UTILIZATION_RATE: Uplink Utilization Rate on BC (%)

- RL9610:BC_TRAN_DOWN_UTILIZATION_RATE: Downlink Utilization Rate on BC (%)

Both counters above provide the ratio of actually used bandwidth over configured bandwidth on a BC of Gb.



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g p ( )

- Check alarms on GDPUP board (BSC6000) or DPUd board (BSC6900) which are the boards that provide

PCU functionality in BSC (internal PCU).

3.Abis interface:- Check for congestion on Abis interface. Congestion will lower the throughput.

- Higher CS and MCS coding schemes will occupy higher number of Abis timeslots. Check relative

parameters for CS transition:

- UPTHDCSUPGRADE1: Uplink TBF Threshold from CS1 to CS2



- UPTHDCSDEGRADE1: Uplink TBF Threshold from CS2 to CS1



- DNTH

179846784 2g huawei performance monitoring

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