org008603 cdma radio network assessment issue1.0

7/30/2019 ORG008603 CDMA Radio Network Assessment ISSUE1.0

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ORG008603 CDMA Radio

Network Assessment

ISSUE 1.0

Course Development Room, Wireless

Product



HUAWEI TECHNOLOGIES CO., LTD. All rights reserved Page 1

Introduction

Concern the running and QoS of current network

Concern the structure of current network and rationality of

configuration

View the network objectively and precisely with rich

experiences in network planning and optimization

Provide professional suggestions and comments in a

quantitative assessment way.




After the study of this course, you should

Understand the contents and indices of

network assessment

Master the CDMA radio network

assessment method and learn the

relevant tools

Learn the organization mode of theCDMA radio network assessment




Chapter 1 Contents of Radio Network

Assessment

Chapter 2 Tools for CDMA Network

Assessment

Chapter 3 Network Assessment

Method

Chapter 4 Organization Mode of

Assessment




Chapter 1 Contents of Radio

Network Assessment

1.1 Purpose of network assessment

1.2 Contents of assessment

1.3 Introduction of indices




Purpose of Radio Network Assessment

The purpose is to give a reasonable assessment of the quality

of network planning, running status of current network, existing

& hidden problems in network running, and utilization of

network investment by analyzing the network running data, so

as to fully learn the overall running status of radio network andprovide direct references for the further network optimization

and future network construction.


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Main Contents of Radio Network Assessment

Coverage

Traffic balancing

Handoff performance

Network interference

Network layout

Call quality

Call establishment

Call drop performance

Worst cell

Network carrying capability




Contents of Radio Network Assessment---

Coverage

Give an overall assessment of network coverage, including

forward coverage, reverse coverage, and the balance between

forward and reverse links. The main forward statistics indices

include Ec/Io and Rx, while the reverse statistics indices mainly

include the Tx of the MS.





Call Quality

Assess the call quality in combination with the call

intermittence, single pass dual fail, cross talking, echo and

background noise in the CQT and DT. The statistics of FER is

also a major channel of assessing the call quality.





Traffic Balancing

Assess the rationality of traffic distribution and cell

configuration in combination with the traffic distribution density

in the network coverage, site configuration, traffic balancing

measures, statistics of unusual busy and unusual idle cells,

and meanwhile assess the network congestion. Theassessment is mainly done with the help of the traffic statistics

indices.





Call Establishment

Assess the status of network call establishment through the

analysis of a large amount of CQT and DT data, and measure

the time and ratio of call establishment success. The traffic

statistics performance indices include many indices about the

access and call establishment. By analyzing these indices, thecall establishment performance can be assessed.





Handoff Performance

Assess the handoff performance of the entire network via the

handoff performance statistics data in the traffic statistics and

the handoff event statistics analysis obtained in the drive test.

The handoff performance assessment mainly includes the soft

handoff performance, hard handoff performance, and whether the ratio of soft handoff is reasonable.





Call Drop Performance

Assess the call drop performance of the network in

combination with the traffic statistics result, customer complaint,

DT data and amounts of dialing test results. The call drop

performance is what operators specially concern. Some

indices, such as call drop rate, traffic drop ratio and ratio of worst cells, are all related to the call drop performance of the

network.





Network Interference

Assess the on-net interference and possible off-net

interference by analyzing the measured DT data, traffic

statistics data and making a site survey, in combination with

the factors, such as network layout, PN planning, distribution of

repeaters, terrain features.





Worst Cell

Analyze and assess the worst cells that satisfy the conditions

by analyzing and measuring the congestion and call drop of

cells in the network, focusing on the analysis of the probability

that a cell falls into the worst cell as well as the reason thereof.





Network Layout

Assess the rationality of the BTS layout in consideration of the

network scale, coverage type, terrain features, design indices

of service area, network structure, densities of BTS & traffic

bearing, and indoor coverage strategy.





Network Bearer Capability

Assess and measure the overall carrying capability of the

CDMA network by analyzing the factors, such as network

coverage, traffic throughput, network interference and network

layout.




This chapter mainly introduces the

main items of radio network

assessment in ten aspects. These arethe results and purposes of the

network assessment, and also the

theoretical foundation for the whole

assessment, so you must learn and

master them.

Summary





Assessment

Chapter 2 Tools for CDMA Network

Assessment


Method

Chapter 4 Organization Mode of Assessment




Chapter 2 Tools for CDMA Network Assessment

2.1 Traffic statistics performance analysis tool

2.2 Dingli Panorama DT tool

2.3 AGILENT spectrum analyzer

2.4 Signaling analyzer




Traffic Statistics Performance Analysis Tool

Output the statistic data as required from a large amount of

source traffic data to analyze the statistics indices, obtain the

key factors that affect these indices, and locate network

problems.




Dingli Panorama DT Tool

Real-time graphical description window

display

Precise geographical location function

DT function

Background analysis statistic and

diagnosis function




AGILENT Spectrum Analyzer

Frequency scanning test. Scan the entire frequency band and

variable frequency band, and analyze abnormal signals and

the interference.

Carrier output power test.

Adjacent channel power test. Determine the adjacent-channel

suppression ratio of the carrier output.

Power test of signal spurious. Determine whether the carrier

output satisfies the spectrum template.




Signaling Analyzer: Tektronix K1297

The signaling analyzer is used to track messages of wireless

interface and analyze the in-depth network problems. In the

radio network assessment, the signaling analyzer is mainly

used to track the Abis interface and the A interface and to

analyze network problems, such as standardization of messages, and find problems about location handoff, call drop

and congestion.




There are many optional tools

available to the network

assessment, but the siteengineering personnel should

select them as required because

the contents and emphasis of

each test may vary.

Summary





Assessment

Chapter 2 Tools for CDMA NetworkAssessment


Method





Chapter 3 Network Assessment Method

3.1 Analysis of traffic statistics indices

3.2 CQT (call quality test)

3.3 DT (drive test)

3.4 Test along highway and railway

3.5 Study on network assessment cases




Introduction of assessment Method

Provide professional suggestions and comments for the

network development in a quantitative assessment way.

The significance of quantization lies in the network

performance index comparison between several local networks

or the network performance index improvement comparisonbefore and after the optimization. It also provides a visual and

objective assessment for the service level and service

capability of the entire network. It is a macro assessment,

which considers the traffic statistics, CQT and DT in a city. A

quantitative assessment score is assigned to each item, and

then a total quantitative score, which represents the current

service level of the network, will be obtained according to the

weight of each item.




Quantitative Assessment Items

Traffic statistics performance index

Indoor CQT

Outdoor multi-point dialing test in government organization,

tourism site, residential area and city plaza.

DT (drive test) on streets in a city

DT along highway, railway, national highway and provincial

highway




Scoring Method for Quantitative Items

Item Total score

of subitem

Weighted

value

Weighted

score

Assessment of key performance

indices of traffic statistics

10050%

50

Indoors CQT 100 15% 15Outdoors multi-point dialing test

in government organ, tourist site,

residential area and city plaza

100

10%

10

DT on streets in a city 100 15% 15

DT along highway, railway and

backbone highway

10010%

10

Total weighted score： 100




Traffic Statistics Index Assessment

The traffic statistics is an important means by which we learn

the running quality of network. The traffic statistics data mainly

deals with call drop, handoff, and running status of network.

Scoring method for key traffic statistics index: A standard value

for assessment is assigned to each index. The assessors addor reduce a score on the basis of the standard value according

to the algorithm listed in the table below.

Take two busy traffic statistic results for each day. Suggested

busy hours: 10:00 ~ 11:00 in the morning, and 19:00 ~ 20:00 in

the afternoon. The busy time segments can be freely taken

according to the busy hour distribution of different local

networks.




Traffic Statistics Index Assessment for Voice

Service

Referenceindex

Standardvalue

Standardscore

Totalpercentage

Totalscore

Algorithm （withstandard value as a

basis）

Call drop rate 2% 8 0.5% 15 ?0.02% -0.1score?0.02% +0.1 score

Call connection

rate

95% 8 100% 15 ?0.07% +0.1 score

?0.07% -0.1 scoreBusy trafficoverflow ratio

5% 8 0 15 ?0.07% -0.1 score?0.07% +0.1 score

Average FER of voice service

1% 8 0 15 ?0.015% -0.1 score?0.015% +0.1 score

Soft handoff success ratio(intra-BS andinter-BS)

98％ 8 100% 15 ?0.03% +0.1 score?0.03% -0.1 score

Hard handoff success ratio(intra-BS andinter-BS)

80％ 8 100% 15 ?0.3% +0.1 score?0.3% -0.1 score




Traffic Statistics Index Assessment for Data Service

The data service is mainly assessed in aspects of traffic flow

(mean peak value) at different times and frame error rate (FER)

of data. In addition, there are other indices, such as forward

and reverse rates, data retransmission rate and bandwidth

occupied by data service. Since the data service is still not themajor service of the CDMA1X network, there is no quantitative

assessment methods available. Here details will not be given.




CQT (Call Quality Test)

CQT includes the indoor and outdoor call quality tests.

Two fixed points will be given for the CQT, and the CQT

testers perform the CQT by dialing the testing MS of each

other.

The test time should be the busy hours of the day.

Input the call duration and time interval via the testing

equipment to automatically finish the dialing & event statistics.

The testers make a subjective statistics by listening to the call

quality and output a CQT report.




CQTSN Index Index definition Score

1 Accessfailure ratio

Access failure ratio ＝Access failure times /total call

attempts ×100%

15

2 Call drop rate Call drop rate ＝Total dropped calls/call establishment

success times ×100%

15

3 Handoff success ratio

Handoff success ratio=Handoff success times/handoff request times

10

4 Location

updatesuccess ratio

Location update success ratio=Total location update

success times/Total location update requesttimes×100%

5

5 Voiceintermittentrate

Voice intermittent rate ＝ Total voice intermittent

times/Total connected calls×100%

15

6 Single passrate

Single pass rate＝Total single passtimes/Total

connected calls×100%

10

7 Rate of echoandbackgroundnoise

Rate of echo and background noise＝

(Total calls withnoise + total ca lls with echo)/total connectedcalls×100%

10

8 Cross talkingrate

Cross talking rate ＝ total cross talking times/total

connected calls×100%

10

9 Access time T=10*a% +8*b% +4*c% +0*d% 10




DT (Drive Test)

The test time should be arranged at the busy hours of the dayand the test time segment should be selected according to the

24-hour traffic curve of the previous workday.

The test route should be within the urban area and cover the

main streets of the urban area equally.

The driving speed is recommended to keep at about 30km/h in

the downtown (busy) area and 40km/h in the less busy urban

area.

Different call establishment time, call durations and call

intervals are required for the testing MS according to whether it

is a Markov call or local call.

A good 4 hours must be required for the test.




Scoring Method for DT

SN Index Score

１ Access failure ratio 15

２ Call drop rate 15

Forward FER 15

Reversse FER 15

Ec/Io 15

Rx_level 10

４

Reverse coverage 15




Drive Test along Highway and Railway

The test time is not strictly stipulated and can flexibly be

arranged at the busy hours of the day.

The test route is the highway or railway between the two tested

cities, or the highway around a city. It is preferable to select the

highway based on the traffic on the highway.

Different call establishment time, call durations and call

intervals are required for the testing MS according to whether it

a Markov call or local call.

Use Dingli Panorama test system, or AGILENT and BlueRosetest system.




Scoring Method for DT along Highway and

Railroad

SN Index Score

１ Access failure ratio 15

２ Call drop rate 15

Forward FER 15

Reverse FER 15

Ec/Io 15

Rx_level 10

４

Reverse coverage 15




BSC Data Analysis

Analyze the relationship between neighboring cells, PN search

window, handoff parameters (T-ADD, T-DROP, T-TDROP and

T-COMP) of the existing network in the BSC database to

assess the network interference, traffic & equalization, reason

for handoff failure and reason for being a worst cell.




Network Assessment Instance (1)

Figure 1 BTS distribution map in urban area





Figure 2 FER distribution map





Figure 3 Ec/Io distribution map





Figure 4 RX-POWER distribution map





Figure 5 TX-POWER distribution map





Figure 6 Hand off distribution map





Figure 7 FER analysis





Figure 8 Ec/Io distribution





Figure 9 RX distribution





Figure 10 TX distribution





Figure 11 Active centralized PN branches




Network Assessment Instance (12)Main parameter settings for the CDMA1X in Nanchang

pilot inc=4

Access parameters

i. Nom_pwr=0

ii. Init_pwr=0

iii. Pwr_step=6

iv. Num_step=3

v. Max_cap_sz=7

vi. Pam_sz=3

System message parameters

i. srch_win_a=5（20chips

ii. srch_win_a=8（60chips

iii. srch_win_a=9（80chips）

iv. Nghbr_max_age=0

pwr_rep_thresh=2

i T_add=24(-12dB)

ii. T_drop=32(-16dB)

iii. T_comp=5(2.5dB)

iv. T_tdrop=3

Power data

v. The power of all BTS sectors is

43.5dBm

vi. The power of all sector pilot

frequencies is 20% of the total power

of the sector




Summary

The network assessment is an integrated,

comprehensive task. The network coverage is a

complete plane, but our test only reflects the status

of some point or line. So we should pay as much

attention as possible to the particularities of the test

and utilize various test tools in a comprehensive

way. Only by doing so, can our assessment results

summarized on the basis of a large amount of data

be more objective and convincing.





Assessment

Chapter 2 Tools for CDMA NetworkAssessment


Method






4.1 Introduction of organization mode

4.2 Work document




Organization Mode of Network Assessment

The radio network assessment is run by a project team.

Project manager: responsible for the overall arrangements for

the work of the project team, coordinating, communicating and

contacting with customers, tracking acceptance of project,

participating in and supervising the implementation of project.

Optimization engineers (several): responsible for the

implementation of a specific project




Organization Mode of Network Assessment

The time for the radio network assessment project should be in

accordance with the work arrangement of the customer. The

valid working time starts with the next day after the engineer

arrives at the site.




Work Document

A XXXX CDMA Network Assessment Report should be

submitted after the network assessment completes in a region.

A XXXX CDMA Network Assessment Report should be

submitted to operator after the network assessment fully

completes in all regions.




Summary

This chapter briefly introduces the

running mode of the organization of the

network assessment. Please

communicate well with the relevant

personnel before carrying out the

network assessment on the site so as to

expect a smooth network assessment.



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