Microsoft Power Point - 8 OMF000603 Traffic Statistics Analysis Issue 1

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Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.

Traffic Statistics Analysis

Page1Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.

Foreword

� Traffic statistics is the performance of network.

� Each traffic item is corresponding one feature of network.

� Through the traffic statistics, can quickly settle the network

problem.


Objectives

� Upon completion of this course, you will be able to:

� Know the traffic statistics system structure of BSC6000

� Understand some often-used traffic measurement items

� Locate some problems through the traffic statistics system


Contents

1. Brief Introduction to BSC Traffic Statistics

2. Often-used Traffic Statistics Items Analysis

3. Locate Problem through Traffic Analysis


Measurement term

� Counter WHAT

� Normal counter：default counter＋extended counter

� Customer counter

� Object WHO

� Physical concept（Board/Cabinet）

� Logical concept（BSC, Cell，TRX）

� Period WHEN

� 5，15，30，60，1440（min）


Hierarchical Structure of Performance

Unit m

Unit 1

Cluster 1

……

…

…Cluster n

Item 1

Item j

Item1

Item k

P

E

R

F

O

R

M

A

N

C

E


Hierarchical Structure of Performance


Counter Setting

� Select Performance > Counter Setting or click to display

the Counter Setting dialog box.

� Counter includes default counter and extended counter

� Support quickly search one certain counter

� Support “all counter select” or just some of them


Counter Setting


Object Type

OptionalOptionalOptionalClass 2

Yes

Save in the

performance data base

YesYesClass 1

Could

be query

Report all

the KPIObject Type


Object Setting

� Menu

� Performance－》Object setting

� The blue color is the class 1

� The green color is the class 2


Period Type

� Real-time （5，15min）


Period Type

� Measure period（30，60，1440min）


Query Result

� Menu

� Performance－》query result

� Get the result of performance

� Support output the files of XLS,JPEG

� Support print on line

� Support counter filter


Query Result

� When query result,

should select

object, counter and

the others setting


Query Result

� In counter selection: black

counter is the default

counter (KPI) or the

extended counter which

has been activated ; gray

counter is the extended

counter which never been

activated.


Query Result� Other setting is about the query period and the time.


Query Result� User can query the needed traffic through the counter filter


Measure Management� Function

� Collecting the Missing Data

� Synchronizing the Performance Data

� Query Measurement Status of Objects and Periodic Counters

� Subscribe Periodic Measurement Results

� Query Reliability of Periodic Measurement Results

� Suspending or resuming Data Collection


Measure Management


Threshold Setting

� Function

� Support threshold add（resume）/suspend

� Each counter has four alarm level

� If there is the high alarm level , the lower alarm level will be

disappear automatically

� Value and Hysteresis together form the conditions for triggering and

stopping the alarm.

For example, in the Increasing direction, an alarm of a certain level is

triggered when the number of measurement results reaches the

Value + Hysteresis of this level; in the Decreasing direction, the

alarm is stopped when the number reaches Value – Hysteresis.


Threshold Setting


Customer Counter Management

� To calculate required measurement counters based on the

existing counters through the arithmetic operation.。

� The customer counter is measured only when all the original

counters contained in the formula are measured

� The customer counter cannot be used to create other user

defined counters.


Customer Counter Management


Contents





Analysis Process

� Systematical logic:

From whole system to specific cell

� Integrality

Observe the change trend of the items for more than one week

and the changing trend of each day.

� Relativity

Relationship between various kinds of traffic statistics items


Analysis Process

� Analysis process

� First we shall analyze and compare the item of BSC

measurement function to have a rough idea for the

whole network.

� During analyzing, if any important items (such as call

drop rate or handover success rate) are abnormal,

we shall do further detailed analysis for the

corresponding items.


Analysis Process

� There are 14 clusters in the

BSC6000 traffic statistics, 4 of them

are important for the optimization.

� BSC Measurement

� MR Measurement

� Call Measurement

� Channel Measurement


Traffic Analysis

� The statistic items in BSC

Measurement Function

are used to measure the

traffic volume of all the

cells in the BSC, including

the call drop, handover

and assignment.


Traffic Analysis

� MR measurement is some

items about measurement

report ,helping the user to

optimization.


Traffic Analysis� Call measurement is the

performance during the

calling, such as

Handover, call drop and

assignment;

measurement object

includes cell, TRX and

the LAPD link


Traffic Analysis

� Channel measurement is

about the channel allocated,

channel conversion and the

channel load


Often-used Items

� In BSC6000, there are some traffic units are important for

the analysis of interference, call drop and handover, more

attention should be paid on those

� Interference band measurement report per TRX

� Power control messages per cell

� Neighbor cell level measurement per cell

� Uplink-and-downlink balance measurement per TRX

� Radio link failure measurement per TRX

� TCHF(H) receive level measurement per TRX


Often-used Items

� In BSC6000, there are some traffic units are important for

the analysis of interference, call drop and handover, more

attention should be paid on those

� KPI measurement per cell

� Outgoing inter-cell handover measurement per cell

� Incoming inter-cell handover measurement per cell

� Intra-cell Handover Measurement

� Call drop measurement per cell

� CPU usage measurement


Interference Band Measurement Report

–85 dBm to –47 dBmInterference band 5





Power Level RangeInterference Band� Interference band is the interference

level contained in the RF RES IND

message that the BTS reports to the

BSC when the channel is idle. There

are five levels. The level range of

each band is set through the LMT.

The higher rank suggests higher

interference level. An idle channel at

interference band 4 or 5 suggests

the existence of interference.


Power Control Messages

� Power Control Messages

per Cell refers to the

measurement of the

transmission power and the

receive level between the

BTS and the MS. It can

measure the coverage of

cell and the receive level or

quality average.


� Neighbor Cell Level Measurement per Cell refers to the

measurement of mean receive level of neighbor cells.

This measurement unit helps to determine whether to

configure neighbor cells.

� If “Number of MRs of Neighbor Cells” and “Strength of

Signals in Neighbor Cells” are higher ,this cell should be

configured as neighbor cell.

Neighbor Cell Level Measurement


� Proper power estimation during network planning is a

prerequisite for normal operation of the system. The uplink

and downlink signals in the coverage area must be

balanced.

� The MR that the BSC receives contains the uplink receive

level and the downlink receive level. The uplink and

downlink balance level is determined by the following

formula: Downlink receive level – uplink receive level – 6 .

Uplink-and-Downlink Balance Measurement


Uplink-and-Downlink Balance Measurement

15 dB, 16 dB, 17 dB, 18 dB, 19 dB, 20 dB11

10 dB, 11 dB, 12 dB, 13 dB, 14 dB10

6 dB, 7 dB, 8 dB, 9 dB9

3 dB, 4 dB, 5 dB8

1 dB, 2 dB7

0 dB6

–2 dB, –1dB, 0 dB5

–5 dB, –4 dB, –3 dB4

–9 dB, –8 dB, –7 dB, –6 dB3

–14 dB, –13 dB, –12 dB, –11 dB, –10 dB2

� –15 dB1

Downlink Receive Level – Uplink Receive level – 6Uplink-and-Downlink

Balance Rank

• Mapping between the uplink/downlink balance rank and the receive level.


Radio Link Failure Measurement

� Radio Link Failure

Measurement per TRX refers

to the measurement of level,

quality, and TA in the MR

during call drops. From this

unit can check is there any

interference or coverage too

low. Judge the call drop

position from “Radio link failure

measurement based on TA”

Number of Radio Link Failures per TRX

Mean TA During Radio Link Failure TRX

TA During Radio Link Failure per TRX

Mean Uplink and Downlink Quality During Radio Link

Failure per TRX

Uplink and Downlink Quality During Radio Link Failure

per TRX

Mean Uplink and Downlink Level During Radio Link

Failure per TRX

Uplink and Downlink Level During Radio Link Failure per TRX

Counter


� The valid MRs that the BSC receives contain the ranks of

the uplink and downlink receive level and the ranks of the

uplink and downlink receive quality

� The receive level has eight ranks, and higher rank

suggests greater receive level

� The receive quality has eight ranks, and higher rank

suggests worse receive quality

TCHF(H) Receive Level Measurement


TCHF(H) Receive Level Measurement

>-607

(-65,-60]6

(-70,-65]5

(-75,-70]4

(-80,-75]3

(-85,-80]2

(-100,85]1

<–1000

Receive Level(dBm)Rank of Receive Level


� KPI measurement is about

the traffic statistics of each

cell, it includes all the

important items, helping

the engineer analyze each

cell performance

KPI Measurement


Outgoing Inter-cell Handover Measurement

� This measurement refers to performance of MS

handover from target cell to the each neighbor cell,

including Handover request times, handover

success times, radio handover success rate

� It also record the handover reason, such as receive

level , bad quality


Outgoing Inter-cell Handover Measurement


Incoming Inter-cell Handover Measurement

� This measurement refers to performance of MS

handover from each neighbor cell to this serving cell,

including Handover request times, handover success

times, radio handover success rate

� From the incoming inter-cell handover measurement,

can locate the neighbor cell which handover to this cell

is not good.


Incoming Inter-cell Handover Measurement


Intra-cell Handover Measurement

� It measures the intra-cell handover request times,

success times.

� This traffic unit also measure the reasons of intra-cell

handover: interference intra-cell handover, TCHF-TCHF

in the AMR calling, intra-cell handover during the channel

conversion, overlaid/underlaid handover.


Intra-cell Handover Measurement


CPU Usage Measurement

� CPU measurement function includes two statistic items:

Percentage of CPU occupation (%)

Peak percentage of CPU occupation (%)

� The former one is the percentage of CPU in busy status

during the measurement cycle. This item indicates the

load of BSC. The latter one is the maximum CPU

occupation within measurement cycle

� It is recommended to register this task on any occasion


CPU Usage Measurement


Call Drop Measurement

� Call drop measurement classify all the call drop by

reasons and the channel type

� According this traffic , can get the detail reason of

call drop ,helping locate the call drop problem


Call Drop Measurement


Contents





Call Drop Analysis

High call drop cell

Radio link failureCall drop measurement

Rx-level

quality

TA

Call drop during the H.O

Call drop in stable state

drop due to the Abis interface

drop due to the equipment

drop due to forced H.O

alarm、hardware

Interference band

Up-down link balance


Call Drop Analysis

� Find out the high call drop rate cell in the “KPI measurement”

� Check those cell’s traffic and the call drop times, exclude the

low traffic high call drop rate cell

� Find out the call drop reason in “call drop measurement ”

� Check the receive level ,quality and the TA in “radio link failure

measurement”

� “Interference band” “Up-down link balance “ and the alarm

system also will help to locate the high call drop reason


Call Drop Analysis� Call drop in stable state: call drop during the calling, the major

reasons are “error indication” and “connect failure”.

� Call drop in handover state: call drop during handover, in other

word , handover failure and reset-up also failure.

� Call drop due to Abis terrestrial link failure: normally the

reason is Abis transmission, also can check alarm system to

find out this problem.

� Call drop due to equipment failure: the call drop reason is

related to hardware fault.

� Call drop due to force handover: during the calling, system

force the MS handover and handover failure , call drop occur.


Radio Link Failure Measurement

� Check receive level, quality and TA in “radio link failure

measurement” to analysis the call drop type:

� Edge call drop: low receiving signaling strength, large TA.

� Short distance call drop: low receiving signal strength and

small TA.

� BQ call drop: high receiving signal strength and poor quality.


Edge Call Drop� Causes ：

MS is out of cell’s effective coverage area, “Island” phenomenon

caused by over shooting or missing neighbor, Isolated site.

� Solutions：

� Add new site to guarantee the effective continuous coverage;

� Add the necessary neighbor;

� Adjust antenna height and antenna downtilt, use high gain antenna;

� Modify some parameters: “SACCH multi-frames”, “Radio link

timeout counter”, “handover threshold”, “handover statistic time”,

etc


Short Distance Call Drop

� Causes：

� Poor coverage caused by complicated terrain or high

dense building

� Solutions ：

� Increase EIRP

� Adjust antenna direction and downtilt, make the main

lobe point to high traffic area

� Adjust parameters related to call drop


Interference Call Drop

� Monitor and locate interference through some traffic statistics：

� Analysis interference band to monitor uplink interference, judging inter

network or intra network interference according the relationship between

interference and traffic

� Monitor uplink and downlink interference via “TCHF(H) receive level

measurement”. If most M.R receive level high and the quality bad, the

interference will be serious

� In “BTS maintenance”-”maintain cell”-”configure frequency scan” ,

can monitor which frequency is interfered





� Solutions：

� Drive test in the suspected area, check the receive level

and the quality; using the spectrum equipment to find out

the interference resource.

� Active frequency hopping, DTX and the Power control to

reduce the interference.


Up-down Link Balance

� Disposing method ：

� Analyze “up-down link balance measurement function”

statistics result and confirm whether the uplink and downlink

are balanced.

� In call drop measurement function, analyze the average

receiving signal strength and quality for both the uplink and

downlink .

� In power control measurement function, analyze the average

receiving signal strength for both the uplink and downlink .


Handover Analysis Process

Low handover success rate

Alarm hardware

Interference band

Up-down link balance

Incoming H.O

Outgoing H.O

Neighbor cell level

KPI measurement

External inter-cellHandover

Internal inter-cellHandover

Intra cell H.O


Handover Analysis

� Find out the problem cells:

� All cells or some cells

� Handover problem direction:

� Outgoing or incoming

� Handover failure object:

� Handover to all the neighbor cells or just handover to certain

cell has problem


Handover Analysis� From “KPI measurement” and “External inter-cell handover”

“Internal inter-cell handover”, find out the cells which

handover success rate is lower

� Analysis the major handover failure is in outgoing or incoming

� Check “Incoming and outgoing handover measurement” to find

out it is just related to certain cell or to all the neighbor cells

� From “neighbor cell revel” to decide deleting or adding

neighbor cell

� Check “Intra-cell handover measurement” to monitor AMR,

overlaid/underlaid performance


Handover Analysis

� Monitor transmission and board alarms

� Analysis “Up-down link balance measurement” to

make sure that cell unbalance or not

� Interference also will make the handover success

rate lower, so should pay more attend to

“interference band” “TCHF(TCHH) receive level

measurement”


Handover Parameters

� Locate and solution：

� Check whether the handover threshold such as TA, BQ and handover

function switch are suitable or not.

� Check whether the successful TCH seizures for handover are much

more than successful TCH seizures for call. If handover times divided

by call times is larger than 3, then it indicates that there may be ping-

pong handover. Check the parameter settings and adjust them (layer

setting, layer handover hysteresis, inter cell handover hysteresis, PBGT

threshold, etc.).

� Check whether the average signal strength is low when the handover

happens. If so, it indicates the edge handover threshold is too low.


Summary

� Traffic Statistics System Basics

� Key traffic Measurement Items

� Traffic Statistics Analysis Method

Thank youwww.huawei.com

Documents

Microsoft Power Point - 8 OMF000603 Traffic Statistics Analysis Issue 1