Ensuring High-quality IPTV Services Part 1. Ensuring High Quality IPTV Services Why offer IPTV? Economical solution that offers new business opportunities.

Ensuring High-quality

IPTV ServicesPart 1

““Ensuring High Quality IPTV ServicesEnsuring High Quality IPTV Services””

Why offer IPTV?Why offer IPTV?

• Economical solution that offers new business opportunities (revenue) for service providers.

• New rates make it possible to easily integrate voice, video and data services over a phone line.

• Simultaneously provide multiple standard and high definition television channels SDTV and HDTV to residences.

• Provide specialized programming such as special events, movies, concerts only when requested by the user. (VoD)


IPTV Delivery– What’s the big IPTV Delivery– What’s the big deal?deal?

• Why can’t I just connect a 13” TV?Why can’t I just connect a 13” TV?

• What’s so different from my old CATV?What’s so different from my old CATV?

• Why can’t I just monitor dropped packets and Why can’t I just monitor dropped packets and % utilization?% utilization?


TV – Traditional vs. IPTVTV – Traditional vs. IPTV

Traditional TV• All channels delivered to subscribers all the time

IPTV• Delivers a small number of channels to each subscriber

• When a subscriber changes channels, a request is sent to an upstream server to:

- activate and deliver the new channels (Join)

- deactivate and stop delivering the old channels (Leave)

• Subscriber can’t tell that all available channels are not present.


IPTV Delivery – Efficient yet FragileIPTV Delivery – Efficient yet Fragile

Efficient • High speed

• Low cost

• Low latency

Fragile• Typically delivered over User Data Protocol (UDP)

• depends on IP network bandwidth

• depends on network components

• depends on configuration


Picture• Black

• Frozen

• Tiling or Blocking

• Better picture quality

• Distortion or pixelization

• Loss of Resolution during motion

Audio• Dropout

• Lip sync

• Varying volume levels

Excessive time to change channel

Customer ObjectionsCustomer Objections


• Video service providers code and compress the video signal,

• Create MPEG-2, MPEG-4 or WM9/VC-1 frames

• Video frames are typically carried by streaming IP Packets using User Datagram Protocol (UDP) for its low latency.

• At Subscriber’s house, the video stream is decoded by a set-top box (STB) and plays on the TV.

IPTV General DeliveryIPTV General Delivery


UDP – Delivering on hopeUDP – Delivering on hope

A good IPTV analyzer needs to provide statistics for dropped packets.

“Dropped packets are preferable to delayed packets”


• Relies on the eye's inability to resolve high frequency color changes

• Relies on the fact that there’s a lot of redundancy with and between frames.

• Predicts the value of pixels in a frame, from the information in adjacent frames. (motion)

• Relies on the fact that, high power tones tend to blot out lower power adjacent tones. So if you can't hear it, don't transmit it.

• Same principal as a *.zip file

MPEG CompressionMPEG Compression

A good IPTV analyzer needs to detect and indicate the compression type – MPEG-2, MPEG4, H.264 etc. Increasing compression decreases the bandwidth but also decreases the quality of the video.


Introducing I, P and B FramesIntroducing I, P and B Frames

Compressing Video Frames• Start with complete still image (I Frame)• Partial frames (P and B Frames) set brightness, color,

motion vectors etc and are much smaller than I Frames.

• P Frames are forward predictors and are partially compressed.

• B Frames are both forward and backward predictors and are heavily compressed.

• Less data is sent using this method


Group of Pictures (GOP) – Sequence of frames• Successive pictures within a coded video stream• Defines how many I, P and B frames in each GOP • M=3, N=12, GOP structure is IBBPBBPBBPBBI• Less data is sent using GOP

MPEG-2: Group of PicturesMPEG-2: Group of Pictures

Only need to update the macro blocks that change or move

A good IPTV analyzer needs to identify the GOP type, structure and min/avg/max length. This defines the time to recover from errors.


MPEG-2 Error RecoveryMPEG-2 Error Recovery

• I Frames are typically once every 15 frames (1/2 second), then the next GOP starts.

• Higher levels of compression may cause errors to last longer• Quantization and motion estimation ensure that errors propagate quickly

A good IPTV analyzer needs to keep statistics for I,P and B frames received vs. packets that are lost, discarded or impaired.


Packet and Frame LossPacket and Frame Loss

Blurred MotionBlurred MotionSingle B-frame lostSingle B-frame lost

1 frame affected1 frame affected

Tiling or Tiling or BlockingBlocking

Single I-frame lostSingle I-frame lost

14 frames affected14 frames affectedA good IPTV analyzer needs to detect excessive problems like blurring and tiling and report the degradation factors contributing to the root cause.


Don’t miss Don’t miss Ensuring High-Quality IPTV Services - Part 2Ensuring High-Quality IPTV Services - Part 2

Tel: 410-789-7890Tel: 410-789-7890Email: [email protected]: [email protected]: www.fetest.comWEB: www.fetest.com

Ensuring High-quality

IPTV ServicesPart 2


IPTV Protocol StackIPTV Protocol Stack

A good IPTV analyzer needs to provide performance statistics at all levels of the protocol stack to isolate a problem layer.


MPEG-2 Transport StreamMPEG-2 Transport Stream

• Fixed Length packets, multiplexes many PES packets.

• Program Identifier (PID) contains information to find, identify and reconstruct program contents

• Continuity Counter (CC) – 4 bit counter to detect loss or out of sequence packets

• Program Clock Reference (PCR) – clock reference to time sync the video and audio

• Sync byte set the start of a TS packet and allows synchronization

• Transport Error Indicator indicates a TS packet error

A good IPTV analyzer needs to detect Sync byte, PID and CC errors to determine the quality of a transport stream.


MPEG-2 MPEG-2 - Program Clock Reference- Program Clock Reference

• PCR – Clock recovery mechanism for MPEG

• 42 bits – 33 bits for 90Khz and 9 bits for 27MHz.

• Inserted in Transport Stream no less than every 100 msec

• Excessive PCR jitter can make it impossible to decode programs.

A good IPTV analyzer must measure PCR jitter.


PSI TablesPSI Tables

• PAT list all programs available in the transport stream with their program ID (PID).

• Each program has a PMT that lists the elementary streams for that program.

A good IPTV analyzer needs to detect PMT, PAT and CAT errors.


Key Factors affecting Zap Time

• Encoding

• Network

• Set top Box (leave and joins)

Zap Time Zap Time (channel change time)(channel change time)

A good IPTV analyzer needs to measure channel change latency (zap time).


User QoEUser QoE

A good IPTV analyzer needs to provide a video preview and a suite of QoE perceptual quality metrics including a MOS score so that the technician knows exactly what the subscriber can expect to see.


• Video Stream (coding, compression)

• IP Core network layer (bandwidth, congestion, integrity etc.)

• ATM payload (XDSL network)

• ADSL2+/VDSL2 (copper loop, modem, impulse noise, rates)

• Fiber (power level, modem, rates)

• Set-top Box (decoding, cable/connections)

• Interaction of layers (xDSL, ATM, IP and Video Transport)

Checkpoints Affecting IPTV QualityCheckpoints Affecting IPTV Quality

A good IPTV analyzer needs to measure IP bandwidth. Standard definition (SD) video typically uses 3-6 Mbps but high definition (HD) can use 8-10 Mbps.


Encoding and Compression• Trade off between quality and compression level• Determines information per IP packet• Affect error recovery time

Jitter• Short term variation in packet arrival time• May affect the transport stream carrying the PCR• Direct impact on the decoding process of the customer’s STB.

Limited Bandwidth• Ultimately determined by customer’s access rate (xDSL or Fiber)• Packet are discarded when maximum bandwidth is exceeded

Packet Loss• Bandwidth limitations, network congestion• Range from single, unnoticeable, missing point of video sequence to long periods of

degraded, pixilated or unavailable images.• Transmission Errors .Can’t recover packets sent with UDP• Lost I frame , there is a good chance of losing the video for a short period• Lost B/P/Si/Sp frames, impact less severe but could lead to poor image quality• Lost MPEG bytes (Sync Bite, PID, Continuity Counter, PSI Tables

Summary: Factors Affecting IPTV Summary: Factors Affecting IPTV QualityQuality


• Attractive price

• Automatically tests all channels with pass/fail results

• Complete Set Top Box (STB) emulation

• Full Motion Picture video preview

• Accurate audio and video MOS scores and QoE/QoS metrics

• Comprehensive Video and Transport Stream statistics

• Drill into detail to determine root cause of problems• Generate detailed and summary pdf reports• Detects degrading conditions that simple TV viewing would

fail to detect• Correlate dropped packets with other events to determine

root cause

Introducing Introducing

Turn your PC into a Powerful IPTV Analyzer


Call or email us to get a free demo and see the whole Call or email us to get a free demo and see the whole picture.picture.

Tel: 410-789-7890Tel: 410-789-7890Email: [email protected]: [email protected]: www.fetest.comWEB: www.fetest.com

Ensuring High-quality IPTV Services Part 1. Ensuring High Quality IPTV Services Why offer IPTV? Economical solution that offers new business opportunities.

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