itu- standrad speech quality

8/9/2019 ITU- Standrad Speech Quality

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Benchmarked Key Performance

Indicators

Crisphine J. Ogongo,

Engineer/Compliance

Communications Commission ofKenya

I!" #orkshop on$eli%ering &ood 'uality elecommunication (er%ice

in a (afe En%ironment in )frica*+airoi, Kenya, -thJuly -01

Nairobi - Kenya 26 - 27 July2010


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Content

ITU/ETSI Standards

QoS Regulation And Comparison

With Intl StdsConclusion

Questions



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I!"/E(I ()+$)2$(



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$efinition

Quality of serice !QoS"#

The collectie effect of sericeperformances$ %hich determine thedegree of satisfaction of a user of theserice !ITU&T E'())"



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#hat 'o( 2eally Is3*et%or+ ,erformance ,arameters translated

to-system design$ configuration$ operation andmaintenance

Quality of serice parameter influenced .y-

Statistics e'g Call 0loc+ Rate1

User/customer re2uirements

Indiidual e3perience e'g inaccessi.ility1&

User opinion/re2uirements feed .ac+ in tothe net%or+ planning process to alterplanned performance and/or practicaloperational standards



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I!" 'O( Parameters 4ith argets

Call Set Up Time/,ost 4ialing 4elayCall Release 4elay

Ans%er Signal 4elay

End to End 0loc+ing5andoer Success Rate/Unsuccessful5andoer

Speech Quality6ultimedia QoS



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Call (et up timeCall type 5"6 6"5 6"6 $efinition

Authentication/ciphering

)') 7'8 7'8

Time interal .et%een the end of

dialing .y the user and thereception .y him of the

appropriate tone or recorded

announcement$ or the a.andonof the call %ithout tone'

,aging/alerting 9') )') 9')

Routing num.er transfer 7') )') 7')

,ost&selection delay

:ocal connection ;') ;') ;')

Toll connection 8') 8') 8')

International connection (') (') (')

O)7 P76+ P(+

5"6 6"5 6"6 +ormal 7oad 8igh 7oad

6ean 9:; 6ean 9:;

7ocal connection 9 :.: 00.: < s s =.: s 9 s

oll connection 00 >.: 0.: s 0- s

International connection 0= 0.: 0.: ? s 00 s 0- s 0.: s



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)ns4er (ignal $elay

P76+ Connection $efinition

Call type 5"6 6"5 6"6 Time interal .et%een theesta.lishment of aconnection .et%een callingand called users$ and thedetection of an ans%ersignal at the originating

e3change'

:ocal connection


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Call 2elease $elay

Call release

delay *secs1

Connection ype

Call type 5"6, 6"5, 6"6 P(+

Calling$ or called$

party clears


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End to End Blocking

099 Impro%ement

P76+On radio Channel :"0; 0;

P76+ to 5i@ed 0; .:;

+ormal 7oad 8igh 7oad

P(+7ocal -;


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!nsuccessful 8ando%ers

Call type 5"6, 6"5, 6"6

,ro.a.ility of unsuccessful land cellular

handoer

)'8?

Is the pro.a.ility that a handoer attempt fails .ecause of

lac+ of radio resources in the target cell$ or .ecause of a lac+

of free resources for esta.lishing the ne% net%or+ connection'

The failure condition is .ased either on a specified time

interal since the handoer re2uest %as first issued or on athreshold on signal strength



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(peech 'uality

,ESQ# & ,erceptual ealuation of speech 2uality

ITU&T ,'(@7An o.ectie method for end&to&end speech 2ualityassessment of narro%&.and telephone net%or+sand speech codecs

,ESQ compares an original signal D!t" %ith adegraded signal !t" that is the result of passingD!t" through a communications system' Theoutput of ,ESQ is a prediction of the percei%ed

ualitythat %ould .e gien to !t" .y suectsina su.ectie listening test!@"'

,roides Speech Quality ra% alues &)'8 to 9'8



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(peech 'uality

Su.ectsin

:isteningTest

Original (ignal D*t"Percei%ed

(peechuality

,ESQ# & ,erceptual ealuation of speech 2uality ITU&T ,'(@7

An o.ectie method for end&to&end speech 2uality assessmentof narro%&.and telephone net%or+s and speech codecs

Nairobi - Kenya 26 - 27 July


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(peech 'uality contAdITU-T P.862.1 - Mapping function for transforming P.862 raw result scores

to MOS

The mapping ensures a omain rescaling from !".# ... $.# to 1."2 ... $.#6

P.862.1_F1

"

".#

1

1.#

2

2.#

%

%.#

$

$.#

#

! 1 " 1 2 % $ #

P.862

MappeP.8

62



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(peech 'uality ContAd

Speech &ualit' epens on Transmission

(ating )actor (The ( *alue is a measure of a &ualit' perception to +e e,pecte +' the

a*erage user when communicating *ia the connection uner consieration

#"6""8""1""

T1211030-99

linear &ualit' scale

high

&ualit'

meium

&ualit'

low

&ualit'

/rea not

recommene

O*erall

(ating 0(0



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(peech 'uality ContAd

2"%alue range

Eui%alent

6O(alues

(peechtransmissio

n ualitycategory

!ser satisfaction

>) R F ) = &ood Satisfied=) R F () < 5air Some users dissatisfied@) R F =) - Bad 6any users dissatisfied

8)

R F @) 0 Poor *early all users dissatisfiedConersion of R alues into 6BS

6BS H 6BS H


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6O( !ser (atisfaction 7e%els

2"alue

6O(alue

Comment Country

R K ) < *early all users dissatisfied

R H 88 7'(;8 6any users dissatisfied Lenya

R H @) ;'< Some users dissatisfied *igeria/Lenya in ;yrs

R H =) ;'8>= Some users dissatisfied

R H () 9')79 Satisfied

2 F0

9'8 Gery satisfied Satisfied

6O( G 6BS H


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$ata/6ultimedia Parameters Criticalto !sers

4elay ariationsBccurs at the transport layer in pac+etiMed data systemsdue to the inherent aria.le arrial times of indiidualpac+ets

Soled through .uffering

4elaythe time ta+en to esta.lish a particular serice from theinitial user re2uest and the time to receie specificinformation once the serice is esta.lished'

,ac+et :ossBf pac+ets or .its during transmission

Includes coding degradation



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6ultimedia *)udio and ideo1 'o(Parameters and targets

KPI

0"4aydelay

$elayariation

Information7oss*Packet7oss 2atio"

P721Audio Conersational Goice F


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6ultimedia 'o( Parameters

KPI (ymmetry "alues $elay

We.&.ro%sing 5T6:


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'O( 2E&!7)IO+ I+ )52IC) )+$CO6P)2I(O+ #I8 I+E2+)IO+)7

()+$)2$(

Case studies

Lenya

*igeria

Uganda

TanMania



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(tatus of Country 'o( 2egulation

+igeria anHania !ganda Kenya

QoS regulated

QoS ,arameters and Targets

Regulations @ @ @

Ouidelines @ D

:icenses @ @ @

B.ectie parameters

Su.ectie ,arameters

,ST* *et%or+ @

Cellular 6o.ile *et%or+

Internet @

4ata !:eased :ines" @ @



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Oecti%e KPIs and argetsBenchmarks

KPI

I!

argets

Kenyan

argets

+igeria anHania !ganda

Completed Call !?" & >) >) P>> >>

Speech Quality !6BS"?age %ith Oood SQ

9') K

6BS 9'8

>8?P7'=

;'< in ;yrs

>( P7')

6BS

P>8 >8

Call 4rop Rate !?" & 7 7 F; 7

Call 0loc+ Rate !?" < ) >) & &

5andoer Success Rate !?" >>'8? (8 >) & &

Call release delay


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(uecti%e 'o( parametersAccount complaint rate

Account complaint resolution time4isconnection complaint rate

4isconnection complaint resolution time

6iscellaneous complaint rate

6iscellaneous complaint resolution time

Jault report rate

Jault repair time

0illing Accuracy

Serice supply time

Call centre ans%er success ratioCall centre ans%er time

Complaint resolution



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Conclusion

ITU&T recommendations hae coered manyQoS issues .ut ery fe% targets hae .eenspecified

Where ITU&T targets are specified$ they

should .e held as minimum thresholds notnegotia.le do%n%ards

6any regulators monitor QoS parameters

Targets adopted .y regulators ary %idely



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'uestions

5o% many regulators monitor QoSperformance of proiders

What are the L,Is monitored

5o% comprehensie are L,Is in addressingcustomers re2uirements

5o% do the targets compare %ithinternational standards or .est practices

Is there need for African Regulators to.enchmar+ and adopt similar and ade2uateparameters and targets



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hank ou

Nairobi - Kenya 26 - 27 July

itu- standrad speech quality

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