Triple-Play Service Deployment

Chapter 7: Troubleshooting Video Service in the Field
The following diagram depicts how objectively measurable
metrics can be mapped to subjective QoE issues, and organizes
these issues into four quality parts: content quality, video stream
quality, transport quality, and transaction quality.
Quality Layers Video QoS Parameters
Video QoE Indicators
Content
Video Stream
Transport
Transaction
V-MOS
Error Indicator Count
Continuity Error
PCR Jitter
PSI Table Data (Error)
IP Packet Loss, Jitter
RTP Packet Loss
RTP Packet Jitter
TCP Re-transmissions
Packet Loss
Service Provisioning
IGMP Latency (BC-TV)
RTSP Latency (VoD)
Figure 7.1 QoS and QoE Mapping for Video Services
Picture: blurring, edge distortion
visual noise
Pixelation, tiling, frame freezes,
Blue screen
Service accessibility,
Channel Change latency
Pause, Play latency
Content quality
The quality of the content is the starting point. Decisions made in
the video headend, where the content is acquired, determine the
variations in quality. The initial quality of the video stream is
established by decisions including which content sources are used,
which compression algorithms are implemented, which encoders
are employed, and by the source quality monitoring system. The
data output of the encoders starts the video packet flow.
There is one critical source quality parameter that can be measured
in MPEG-2 transport stream video flows at the customer premises
and in the last-mile access network: the video transport packet
error indicator count. Figure 7.2 shows a schematic diagram of the
transport stream packet header. The components of the transport
stream packet header are defined in ISO/IEC 13818.
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