Www.symmetricom.com QoE Division Yves Cognet CTO Quality of Experience metrics for IPTV.
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Transcript of Www.symmetricom.com QoE Division Yves Cognet CTO Quality of Experience metrics for IPTV.
www.symmetricom.com QoE DivisionYves Cognet
CTO
Quality of Experience metrics for IPTV
QoS as perceived by an end-user is called QoE (Quality of Experience)
QoE can be measured and benchmarked
QoE relates how an application is perceived by an end-user.
QoE metrics are content dependant and are impacted by network impairments as well as
content impairments
QoS versus QoE (highlight)
Quality of ExperienceQuality of Service Describes how IP can be used for offering Differentiated Services
Describes how Differentiated Services can improve Quality of Services (aka for offering Class Of Services)
QoS describes how a network is performing for a specific Class Of Service. QoS metrics are network centric metrics.
“Operators want to know the video performance as perceived by the customer through the IP TV network….”.
Key Challenges to solve
Assure service delivery (end2end monitoring)
Monitor service quality (Quality of Experience)
Reduce time to fix (identify the problem and diagnose the source)
Speed up deployment
Deliver what the customer is paying for
Reduce customer churns
Reduce cost of support
Secure revenue streams (competition)
What was missing
QoS for IPTV is well known but QoE for IPTV is in its infancy. The V-Factor™ patented technology is recognized as the “critical missing link” between IPTV QoE and IPTV QoS.
V-Factor technology takes into account Network impairments (delay, jitter, loss, miss ordering,..) as defined
by ITU Y1540/41and IETF RFC2330 Transport impairments (MPEG2 TS streamer jitter) as defined by
ETSI TR 101290 Content impairments (is codec dependant and measure the
quantization, size of macroblocks, …),
The V-Factor provides a score that measures the impact of losses/jitter on I, B or P frames/slices by simulating the Human Vision System.
IPTV QoE methodologies
Subjective QoE testing
Average opinion of many people concerning
quality of Video
Not scalable
Objective QoE testing
Score delivered by a system that rate the
quality of the video as perceived by a user
Human Human Vision Vision
System System ModelModel
Human Human Vision Vision
System System ModelModel
Video Quality Measurement Full Reference (FR)
Full Reference
Processor Processor
Original Video Received Video
Original Video
Transmitted Video Signal
ITU-T J.144
Video Quality Measurement Reduced Reference (RR)
Reduced-Reference •Spatial (Pixel) and Temporal (Motion) Information
Reduced-Reference Signal
Processor Processor
Transmitted Video Received Video
ITU-T J.143
Video Quality Measurement No-Reference (NR)
Processor Processor
Transmitted Video Received Video
V-Factor™
No-Reference• V-Factor – Moving Picture Quality Metrics (MPQM) based on the Human Vision System
What is V-Factor?
Based on MPQM (Moving Picture Quality Metrics) Considers both Network based metrics and Content based metrics
Measures Perceived Video and Audio Quality over time
What the V-Factor does 1/2
Transmitted Video Received Video
Multiplexer/streamer STB
MPEG PES packet analysisI,B,P frames and slices analysisAudio PESVideo PES : Slices, Macro block, Block, Quantizer
V-Factor analyses all PES video and audio packets in real time and collect statistics about I,B,P frames and slices. PES packets analysis is codec dependant (MPEG2, H264,..).
What the V-Factor does 2/2
Transmitted Video Received Video
IP/RTP/Transport Stream header inspectionPCR (jitter)Packet lossBandwidth
Multiplexer/streamer STB
V-Factor collects network statistics from IP header or RTP MPEG2TS header, Network packets analysis is transport dependant (RTP only, MPEG2TS over UDP, MPEG2TS over RTP over UDP, ..).
IP packets (6 to 7 PES)
The MPQM model is fed from network impairments at the IP level (as defined by ITU U1540/41 and RFC2330) and also information collected from the content of the compressed video layer (GOP, Quantizer,..)The PLR is computed from network impairments, the Program Clock Reference (PCR) Jitter and Network Jitter.
Loss Loss modelmodel
Mar
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del
sM
arko
v m
od
elsBursty
Loss Episode
Single Loss
MP
QM
mo
del
Packet Loss Rate (PLR) probability
Codec type , I/B/P/S, Quantizer information, bandwidth
V-Factor
Human Vision System (HVS)
En
tro
py
En
tro
py Γ
Patented
Au
dio
Au
dio Sound
MOS
TR 101 290
Co
nte
nt
Imp
air
me
nts
Co
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nt
Imp
air
me
ntsPLC (FEC)
De
Jit
ter
Bu
ffe
rD
e J
itte
r B
uff
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Network Jitter
Buffer size
Network impairments
Codec impairments
MPQM
V-Factor Measurements
Transport Stream analysis (PCR, Out
of sequence)
V-Factor Parameters
All parameters are “per sample” counters unless otherwise notedPlease see MPEG-2 System Specifications and ETSI TR101290 for more detailed explanations of these parameters
Network related parameters Jitter Discards – Number of frames discarded due to jitter Network Loss Probability – Statistically accurate predictive calculation of frame loss at the PES
level Out of Sequence – Number of miss-ordered frames delivered Max Loss Episode Length – Maximum number of lost frames per episode Max Loss Episodes – Cumulative count of loss episodes since first observation In Sequence – Number of properly ordered frames delivered PLC – packet loss concealment (such as FEC or other mechanisms) ETSI TR 101 290 group 1 and 2 – standard DVB parameters for MPEG2 TS
Content related parameters Program Rate – Transport stream rate in kilobits per second as observed Program Clock Rate Overall Jitter – Jitter of synchronization stream in microseconds (from the
streamer) I frame Count – Number of “I” (Intra) frames/slices for this sample period P frame Count – Number of “P” (Predictive) frames/slices for this sample period B frame Count – Number of “B” (Bi-directional) frames/slices for this sample period Compression Ratio – Ratio of I frames to I+P+B frames QUANT_SCALE – Worst case value of the QUANT_SCALE per reporting period V-Factor – QoSmetrics specific calculation of user perceived video quality, details elsewhere Sound codec Video codec (H264/CABAC – MPEG2 ,…) Multicast Join Time – Actual time the stream was joined in “epoch” seconds Multicast First Time – Actual time the first data arrived in “epoch” seconds
IP TV – QoE metric
Test 1 - 0% packet loss / 0% jitter / 0% dup Test 3 - 1% packet loss / higher jitter / 1% dup
Test 2 - 0,1% packet loss / some jitter / 0,1% dup
Test 1 Test 2 Test 3
Deploying the V-Factor
Secure revenues by keeping customer satisfaction
Integrate with NOC & customer support workflows
Accelerate and secure IPTV deployment during rollout Keep customer support costs under control
By deploying probes before and after encryption, the solution overcomes most situation when encryption is used for DRM purpose.
IPTV in Service Monitoring Measure Performance by Channel and by Geographic Region
"One of the major demands in the emerging IP video market was the need for a video scoring metric suitable for the IPTV market. With the announcement of V-Factor™, which is the first product suitable for large-scale deployment of IPTV, QoSmetrics eliminated one of the major stumbling blocks for successful deployment."
“QoSmetrics’ V-Factor™ is a sophisticated service analysis portfolio that maximizes video quality, giving service providers what they need to avoid network performance impairments – setting the company apart from its competitors,” said Brian Dolan, editor of Fierce-IPTV. “The company’s customer list is very impressive, and will only get better as U.S. deployments continue, making them a Fierce15 winner.”
Awards & Recognition
The NetAgent product has been named a Best of Interop Finalist for this week’s Networld+Interop exhibition held annually in Las Vegas.
Who is using V-Factor
ITPV Customers/Trials OEM/Distribution Partners
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