ETSI TS 102 250-6 V1.3.1 (2019-11)

Speech and multimedia Transmission Quality (STQ); QoS aspects for popular services in mobile networks; Part 6: Post processing and statistical methods

RTS/STQ-00224-6m

General Information

• Status: Published
• Publication Date: 11-Nov-2019
• Technical Committee: STQ MOBILE - STQ Mobile
• Current Stage: 12 - Completion
• Due Date: 09-Nov-2019
• Completion Date: 12-Nov-2019

Standards Content (Sample)

ETSI TS 102 250-6 V1.3.1 (2019-11)






TECHNICAL SPECIFICATION
Speech and multimedia Transmission Quality (STQ);
QoS aspects for popular services in mobile networks;
Part 6: Post processing and statistical methods

---------------------- Page: 1 ----------------------
2 ETSI TS 102 250-6 V1.3.1 (2019-11)



Reference
RTS/STQ-00224-6m
Keywords
3G, GSM, network, QoS, service, speech
ETSI
650 Route des Lucioles
F-06921 Sophia Antipolis Cedex - FRANCE

Tel.: [phone]  Fax: [phone]

Siret N° 348 623 562 00017 - NAF 742 C
Association à but non lucratif enregistrée à la
Sous-Préfecture de Grasse (06) N° 7803/88

Important notice
The present document can be downloaded from:
http://www.etsi.org/standards-search
The present document may be made available in electronic versions and/or in print. The content of any electronic and/or
print versions of the present document shall not be modified without the prior written authorization of ETSI. In case of any
existing or perceived difference in contents between such versions and/or in print, the prevailing version of an ETSI
deliverable is the one made publicly available in PDF format at www.etsi.org/deliver.
Users of the present document should be aware that the document may be subject to revision or change of status.
Information on the current status of this and other ETSI documents is available at
https://portal.etsi.org/TB/ETSIDeliverableStatus.aspx
If you find errors in the present document, please send your comment to one of the following services:
https://portal.etsi.org/People/CommiteeSupportStaff.aspx
Copyright Notification
No part may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying
and microfilm except as authorized by written permission of ETSI.
The content of the PDF version shall not be modified without the written authorization of ETSI.
The copyright and the foregoing restriction extend to reproduction in all media.

© ETSI 2019.
All rights reserved.

DECT™, PLUGTESTS™, UMTS™ and the ETSI logo are trademarks of ETSI registered for the benefit of its Members.

3GPP™ and LTE™ are trademarks of ETSI registered for the benefit of its Members and
of the 3GPP Organizational Partners.
oneM2M™ logo is a trademark of ETSI registered for the benefit of its Members and
of the oneM2M Partners.
®
GSM and the GSM logo are trademarks registered and owned by the GSM Association.
ETSI

---------------------- Page: 2 ----------------------
3 ETSI TS 102 250-6 V1.3.1 (2019-11)
Contents
Intellectual Property Rights . 6
Foreword . 6
Modal verbs terminology . 6
Introduction . 6
1 Scope . 7
2 References . 7
2.1 Normative references . 7
2.2 Informative references . 7
3 Definition of terms, symbols and abbreviations . 8
3.1 Terms . 8
3.2 Symbols . 8
3.3 Abbreviations . 8
4 Important measurement data types in mobile communications . 9
4.1 Data with binary values . 9
4.2 Data out of time-interval measurements . 9
4.3 Measurement of data throughput . 10
4.4 Data concerning quality measures . 10
5 Distributions and moments . 10
5.1 Introduction . 10
5.2 Continuous and discrete distributions. 11
5.3 Definition of density function and distribution function . 11
5.3.1 Probability Distribution Function (PDF) . 11
5.3.2 Cumulative Distribution Function (CDF) . 12
5.4 Moments and quantiles . 12
5.5 Estimation of moments and quantiles . 14
5.6 Important distributions . 15
5.6.1 Overview of distributions . 15
5.6.1.1 Continuous distributions . 15
5.6.1.2 Normal distribution . 16
5.6.1.3 Standard normal distribution . 16
5.6.1.4 Central limit theorem . 17
5.6.1.5 Transformation to normality . 17
5.6.1.6 Log-Normal distribution . 17
5.6.1.7 Use-case: transformations . 18
5.6.1.8 Exponential distribution . 18
5.6.1.9 Weibull distribution . 19
5.6.1.10 Pareto distribution . 20
5.6.1.11 Extreme distribution (Fisher-Tippett distribution) . 21
5.6.2 Overview of testing distributions . 21
5.6.2.1 Chi-Square distribution with n degrees of freedom . 21
5.6.2.2 Further relations . 23
5.6.2.3 Relation to empirical variance. 23
5.6.2.4 Student t-distribution . 23
5.6.2.5 Relation to normal distribution . 24
5.6.2.6 F distribution . 25
5.6.2.7 Quantiles . 26
5.6.2.8 Approximation of quantiles . 26
5.6.2.9 Relations to other distributions . 27
5.6.3 Overview of discrete distributions . 27
5.6.3.1 Bernoulli distribution . 27
5.6.3.2 Binomial distribution . 28
5.6.3.3 Geometric distribution . 29
5.6.3.4 Poisson distribution . 30
ETSI

---------------------- Page: 3 ----------------------
4 ETSI TS 102 250-6 V1.3.1 (2019-11)
5.6.4 Overview of transitions between distributions and appropriate approximations . 31
5.6.4.1 From binomial to Poisson distribution . 31
5.6.4.2 From binomial to Normal distribution . 31
5.6.4.3 From Poisson to Normal distribution . 31
5.6.5 Truncated distributions . 32
5.6.6 Overview of distribution selection and parameter estimation . 32
5.6.6.1 Test procedures . 32
5.6.6.2 Chi-Square test . 32
5.6.6.3 Kolmogorov-Smirnov test . 32
5.6.6.4 Shapiro-Wilk test . 32
5.6.6.5 Parameter estimation methods . 33
5.7 Evaluation of measurement data . 33
5.7.1 Statistical tests . 33
5.7.1.1 Formulation of statistical tests. 33
5.7.1.2 Classes of statistical tests . 34
5.7.1.3 Tests for normal and binomial data . 34
5.7.1.4 One-sample tests for normal data . 34
5.7.1.5 Two-sample tests for normal data . 35
5.7.1.6 Test for binomial data . 36
5.7.1.7 Distribution-free tests for location . 37
5.7.1.8 Sign tests . 37
5.7.1.9 Sign rank test . 37
5.7.1.10 Wilcoxon rank sum test . 38
5.7.2 Confidence interval . 38
5.7.2.1 Binomial distribution . 38
5.7.2.2 Normal (Gaussian) distribution . 40
5.7.3 Required sample size for certain confidence levels . 41
6 Visualization techniques. 42
6.1 Visualization of static data . 42
6.1.1 Histograms . 42
6.1.2 Barplots . 42
6.1.3 QQ-Plots . 43
6.1.4 Boxplots . 43
6.2 Visualization of dynamic data . 44
6.2.1 Line Diagrams . 44
6.2.2 Temporal changing Boxplots . 44
6.2.3 MMQ-Plots . 45
7 Time series modelling . 45
7.1 Descriptive characterization . 45
7.1.1 Empirical moments . 45
7.1.2 Decomposition of time series. 48
7.1.3 Determination of the trend component . 49
7.1.3.1 Trend function types . 49
7.1.3.2 Linear trend function . 50
7.1.3.3 Polynomial trend function . 50
7.1.3.4 Non-linear trend models . 50
7.1.3.5 Trend estimation . 51
7.1.3.6 Transformation of time series by filtering . 52
7.1.3.7 Linear filters . 52
7.1.3.8 Exponential filters . 54
7.1.4 Seasonal component . 55
8 Data aggregation . 56
8.1 Basic data aggregation operators . 56
8.2 Data sources, structures and properties . 57
8.2.1 Raw, Performance and Event data . 57
8.2.2 Key Performance Indicators / Parameters . 58
8.3 Aggregation hierarchies . 58
8.3.1 Temporal aggregation . 58
8.3.2 Spatial aggregation . 59
8.4 Parameter estimation methods . 59
ETSI

---------------------- Page: 4 ----------------------
5 ETSI TS 102 250-6 V1.3.1 (2019-11)
8.4.1 Projection method . 59
8.4.2 Substitution method . 59
8.4.3 Application of estimation methods . 60
8.4.4 Attributes of aggregation operators . 60
8.5 Weighted aggregation . 61
8.5.1 Perceived QoS . 61
8.5.2 Weighted quantiles . 62
8.6 Additional data aggregation operators . 63
8.6.1 MAWD and BH . 63
8.6.2 AVGn . 63
9 Assessment of performance indices . 63
9.1 Estimation of performance parameters based on active service probing systems . 63
9.2 Monitoring concepts . 63
9.2.1 Control charts . 63
9.2.2 Other alarming rules . 64
9.3 Methods for evaluation of objectives . 64
9.3.1 Desirability functions . 64
9.3.2 Loss functions . 65
Annex A (informative): Examples of statistical calculations . 66
A.1 Overview . 66
A.1.1 Step by step computation . 66
A.1.2 Computation using statistical software . 68
A.2 Transition from binomial to normal distribution . 69
A.3 Definitions of ETSI EG 201 769 [i.1] . 70
A.4 Calculation of confidence intervals . 70
A.4.1 Estimated rate 5 % . 70
A.4.2 Estimated rate 50 % . 71
A.4.3 Estimated rate 95 % . 72
A.4.4 Lower limit of confidence intervals according to Pearson-Clopper formula . 73
A.4.5 Upper limit of confidence intervals according to Pearson-Clopper formula . 74
A.4.6 Span of confidence intervals according to Pearson-Clopper formula . 75
A.5 Different sample sizes . 77
A.6 Calculation methods . 79
A.6.1 Calculation of quantiles . 79
A.7 Reporting of results . 80
A.7.1 Methods to use . 80
A.7.2 Number of significant decimals . 82
A.7.3 Rounding of end results . 82
Annex B (informative): Bibliography . 83
History . 84

ETSI

---------------------- Page: 5 ----------------------
6 ETSI TS 102 250-6 V1.3.1 (2019-11)
Intellectual Property Rights
Essential patents
IPRs essential or potentially essential to normative deliverables may have been declared to ETSI. The information
pertaining to these essential IPRs, if any, is publicly available for ETSI members and non-members, and can be found
in ETSI SR 000 314: "Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to ETSI in
respect of ETSI standards", which is available from the ETSI Secretariat. Latest updates are available on the ETSI Web
server (https://ipr.etsi.org/).
Pursuant to the ETSI IPR Policy, no investigation, including IPR searches, has been carried out by ETSI. No guarantee
can be given as to the existence of other IPRs not referenced in ETSI SR 000 314 (or the updates on the ETSI Web
server) which are, or may be, or may become, essential to the present document.
Trademarks
The present document may include trademarks and/or tradenames which are asserted and/or registered by their owners.
ETSI claims no ownership of these except for any which are indicated as being the property of ETSI, and conveys no
right to use or reproduce any trademark and/or tradename. Mention of those trademarks in the present document does
not constitute an endorsement by ETSI of products, services or organizations associated with those trademarks.
Foreword
This Technical Specification (TS) has been produced by ETSI Technical Committee Speech and multimedia
Transmission Quality (STQ).
The present document is part 6 of a multi-part deliverable. Full details of the entire series can be found in part 1 [i.2].
Modal verbs terminology
In the present document "shall", "shall not", "should", "should not", "may", "need not", "will", "will not", "can" and
"cannot" are to be interpreted as described in clause 3.2 of the ETSI Drafting Rules (Verbal forms for the expression of
provisions).
"must" and "must not" are NOT allowed in ETSI deliverables except when used in direct citation.
Introduction
All the defined quality of service parameters and their computations are based on field measurements. That indicates
that the measurements were made from users point of view (full end-to-end perspective, taking into account the needs
of testing).
It is assumed that the end user can handle his mobile and the services he wants to use (operability is not evaluated at this
time). For the purpose of measurement it is assumed:
• that the service is available and not barred for any reason;
• routing is defined correctly without errors; and
• the target subscriber equipment is ready to answer the call.
Speech quality values measured should only be employed by calls ended successfully for statistical analysis.
However, measured values from calls ended unsuccessfully (e.g. dropped) should be available for additional evaluations
and therefore, need to be stored.
Further preconditions may apply when reasonable
...