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ITU Workshop on “Performance, Quality of Service and Qu
Experience of Emerging Networks and Services”
(Athens, Greece, 7-8 September 2015)
Impact of LTE/VoLTE network architectuon QoS/QoE measurements
Henry KwongSenior Consultant, [email protected]
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a g e
n d
a 1. Omnitele Introduction
2. Background: LTE Interfaces and VoLTE
3. QoE & QoS measurements for LTE networks
4. Key take-aways
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Maximised Experience, Minimised Cost
We provide consulting and expert services for telecom
operators and regulators in network strategy, design
and quality assurance. Our mission is to maximise
mobile subscriber quality of experience and minimise
operator network expenditures.
Delivering Omnitele ExperienceThe company was founded in 1988 to set up world’s
first GSM network. Since then we have completed over
1000 projects in over 80 countries around the globe.
Always delivering Omnitele Experience – a fact proven
by our long lasting client relationships.
International And Independen
Our headquarters is located in Helsi
have local presence in the Netherland
is owned by Finnish telecom invest
independent of operator groups and n
The Omnitele WayOur unique way of working sets us
competition and gives us a strong iden
of telecommunications. We call this th
which means being Straightforward
Intelligent.
www.omnitele.com
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TechnologyStrategy
Design andOptimisation
Audit andBenchmark
our services
maximised customer experienceminimised network cost
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a g e
n d
a
1. Omnitele Introduction
2. Background: LTE Interfaces and VoLTE
3. QoE & QoS measurements for LTE networks
4. Key take-aways
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LTE Architecture and Traffic PathNodes, Interfaces and User plane traffic paths for LTE
eNodeB
eNodeB
MME
S-GW P-GW
HSS
X 2
S1-U S5/S8 SGi
S1-MME
S 1 1
S6a
CoreRAN
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Voice over LTE (VoLTE) Traffic paths, and compared to 3G voice traffic paths
VoLTE Architecture and Traffic Pa
eNodeB
MME
S-GW P-GW
HSS
S1-U S5/S8 SGi
S 1 1
S6a
LTE-Uu
MGW
Gm
RNC
MSC/S
NodeBUu Iub IuCS (UP)
CoreRAN
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Key Differences: voice service Key differences between VoLTE and legacy voice for the end user :
− Some possible differences in call setup time and voice quality dependiusage
− Very little else
Key differences between VoLTE and legacy voice for the network :
− Legacy voice has its dedicated path for signalling and user planes
− VoLTE shares its user and signalling paths with packet switched traffic
volume of Internet traffic)
− VoLTE signalling is carried inside a data user plane!
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Implications Measurement of standard “best effort” data services quality in LTE network
similar to that of legacy 2G/3G networks
For many operators, Voice over LTE is the first and possibly most importan
service that requires full implementation of QoS on bearer level, IP and low
levels
− Consistent traffic marking and treatment required, details
outside scope of this presentation
Measurement and Monitoring of voice service quality in LTE
is much more important than in legacy network, and canbe more difficult
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a g e n d
a
1. Omnitele Introduction
2. Background: LTE Interfaces and VoLTE
3. QoE & QoS measurements for LTE networks
4. Key take-aways
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Quality of Experience measureme Quality of Experience (QoE) measurements should always be completed as
the results are dependant on perceptions and expectations
Hence the measurement of QoE over LTE networks is the same as other ne
In practice, expectations of quality would likely have a big impact on QoE r
the impact of using LTE network instead of 2G/3G networks on:
− Data services
• File Transfer
• Social Media
• Web Browsing
• Audio/Video Streaming
− Voice services
• VoLTE
• CSFB
− In short: How (and how much) have the services improved in the LTE
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Quality of Service measurements Quality of Service (QoS) measurements of typical Over The Top (OTT) inte
services are described in Omnitele’s Session 6 presentation “Network Perfo
vs. App Testing; Findings and Considerations” QoS measurements of VoLTE can be done either in the handset or the netw
with its advantages and disadvantages. There are known solutions to carry
QoS measurements already on the market
For VoLTE QoS measurements made on the handset, the concepts used ar
similar/same as legacy voice QoS measurements – each handset/terminal
the relevant KPIs and incoming stream quality
VoLTE QoS measurements made on the network are done somewhat differ
legacy voice due to the different architecture, but still allows:
− QoS measurements to be made on a large number of users
− Streams in both directions to be measured
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VoLTE interfaces for QoS measuremeKey interfaces for QoS measurements for network based capture probe measu
interfaces will depend on desired KPIs, network design and tool capability.
eNodeB S-GW P-GWS1-U S5/S8 SGiLTE-Uu
MGW
MME HSS
S 1 1
S6a
S v
MSC/S
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VoLTE QoS related KPIs KPIs/KQIs associated with VoLTE QoS are typical to voice services:
− Voice Quality (eg. POLQA algorithms, for wideband or narrowband code
− Call success rate− Call setup success rate
− Call drop rate
− Call setup time
Other KPIs relevant to VoLTE are:
− SRVCC (Single Radio Voice Call Continuity) handover success rate− SRVCC handover voice interruption time
− RTP packet loss
− RTP jitter
− IMS KPIs (e.g. Initial Registration Success Rate)
− EPC KPIs (e.g. Bearer Establishment Success Rate)
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QoS measurement issuesKey issues faced in LTE QoS measurements (some not specific to LTE/VoLTE):
Deciding where to measure and how to measure
(defined by what the measurements are targeted to do)
Real network is not just LTE, but also 3G and 2G
(take into account legacy network & architecture)
Sheer volume of traffic
(effective filtering required)
Relatively low amount of VoLTE traffic(effective filtering required)
Correlating the QoS results to ensure the final results
provide an accurate representation of the actual network
performance
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a g e n d
a
1. Omnitele Introduction
2. Background: LTE Interfaces and VoLTE
3. QoE & QoS measurements for LTE networks
4. Key take-aways
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Summary and Conclusion
QoE for LTE and VoLTE would be measured in same
way as for legacy networks
QoS for LTE best-effort data services would be measured
in similar way as legacy mobile data services
QoS for VoLTE service should be carefully measured, in pa
take into account the difference in network architecture co
legacy voice/circuit-switched network.
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thank you for your attention!
Questions?
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Contact details Omnitele Ltd
Name Phone +358 9 695 991
Title Email [email protected]
Phone Website www.omnitele.com
Email Address Omnitele Ltd. Mäkitorpantie 3B P.O. Box 96
We answer
Henry Kwong
Senior Consultant
+358 440 432 900
mailto:[email protected]://www.omnitele.com/http://www.omnitele.com/mailto:[email protected]
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maximised customer experienceminimised network cost
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