Uplink Receiver Encoder Multiplex Local DPI Edge Device STB August 25-27, 2009 San Juan, PR Director Technical Sales (954) 427-5711 (954) 605-5094 Page 1
Digitalization Drivers (Why go Digital) Competition DTH Operators (DirecTV, Sky, Dish) Telcos (IPTV) Other CATV operators Piracy Most Analog CATV systems have piracy of 30% or more After going Digital (encrypted) systems may loose some basic subscribers However, within a year most (~70%) pirate subs come back as paying customers Expand offering Not enough BW to add more services (HSD, PPV, Premium Channels) Can compress an average of 6 programs @ 64 QAM and 9 programs @ 256 QAM into a 6 MHz BW channel. Improve Service Quality DVD quality Video Dolby 5.1 Audio (Home Theater) Page 2
Digital Television (Basic Terms) DTV (Digital Television) [Standard & High Definition] DTV uses digital encoding schemes and digital compression to reduce the required data rate for delivering the images. Except for compression artifacts, DTV is more immune to image degradation than analog TV, delivering higher quality of Audio & Video, up to the limits of signal reception. SDTV (Standard Definition Television) [Analog & Digital] NTSC (National Television Systems Committee) The NTSC system delivers 525V (vertical) lines @ 60 interlaced fields/second (30 frames/sec) TV Screen Resolution (effective): 480V x 640H lines HDTV (High Definition Television) Has approximately twice the Horizontal and Vertical resolution in both directions compared to SDTV Page 3
Pixels, Lines, Fields and Frames Progressive Scan (60 Frames/sec) RGB Additive Color Mixing Horizontal Resolution Vertical lines of pixels Left to Right Typically pixel shapes Vertical Resolution Horizontal lines of pixels Top to Bottom Field 1 = Half Frame Field 2 = Half Frame Interlaced Scan (30 Frames/sec) Field 1 = Half Frame Field 2 = Half Frame Page 4
Common Video Resolutions 1080p 1080i Page 5
HDTV (Line Resolution Comparison) Vertical Resolution (Scan H-Lines) (Rows) (Top to Bottom) Horizontal Resolution (Scan V-Lines) (Columns or pixels) (Left to Right) Aspect Ratio (Width : Height) Display Rate (Frames or fields per second) p = Progressive scan i = Interlaced scan ATSC Digital TV Format 1080 1920 16:9 (30)i, (30)p, (24)p HDTV 720 1280 16:9 (60)p, (30)p, (24)p HDTV 480 704 16:9 or 4:3 (30)i, (60)p, (30)p, (24)p SDTV 480 640 4:3 (30)i, (60)p, (30)p, (24)p SDTV Page 6
HDTV (720p vs 1080i) 720p60 Primarily used in the USA Presents a complete Frame 60 times a second Highest temporal (motion) Resolution in action video Spatial Resolution (Sharpness) is close to 1080i ABC, ESPN, Fox 1080i30 Used worldwide Presents a complete Frame 30 times a second Presents one of two (interlaced) field 60 times a second Highest detail in still or slow moving pictures May need to use filtering to prevent flicker CBS, NBC, HBO, Showtime, PBS, CW, My33 Page 7
Interlaced vs. Progressive The original image is a vertical line panning across the screen in less than a second (shown here in slow motion) Progressive Scan draws continuous dots from top left corner to bottom right corner Interlaced Scan draws two sets of dots: the first skips every other line, the second set fills in the lines skipped on the first Page 8
Digital Modulation (QPSK - Satellite) 11 @315 00 @45 45 135 225 315 Constant Amplitude 10 @225 01 @135 11 10 00 01 Constellation Chart (w/ Grey Coding) Waveforms 20MS/s (20 mega-symbols) = 40Mb/s (40 mega-bits per second) QPSK modulates phase only, not amplitude or frequency Four phase states or symbols, each with two data bits Offset QPSK and p/4 QPSK enhance efficiency Double the data of AM or FM techniques Used primarily in Satellite transponders (MPEG-2) Emerging schemes: 8-PSK, 16APSK, 32APSK Change in Phase 8PSK Constellation Chart Page 9
Digital Modulation (QAM) Quadrature Amplitude Modulation (QAM) Preferred modulation method in Digital CATV QAM modulates the phase and amplitude of the carrier signal 64-QAM has 64 symbols each with 6 bits 256-QAM has 256 symbols each with 8 bits CMTS Returns also use: 16-QAM (DOCSIS 1.1), 32 and 128-QAM (DOCSIS 2.0) 6 MHz 256-QAM channel can has the same data capacity as a 27 MHz QPSK Satellite transponder channel. 25 channels in cable system could easily carry 125, high quality video and audio programs (with 5:1 compression) Page 10
Binary vs Decimal Decimal Base 10 0,1,2,3,4,5,6,7,8,9 Numbers have to reach 9 before rolling over to the next magnitude Binary Base 2 0,1 Numbers have to reach 1 before rolling over to the next magnitude Counts begin with 0 Counts begin with 0 Magnitude of digit 10 2 10 1 10 0 2 4 2 3 2 2 2 1 2 0 100 10 1 16 8 4 2 1 0 01 01234567890123456 01 10 1010 10101010 1010101010101010 Number of states available 1000 100 10 32 16 8 4 2 Base 10: ten different numbers or states (0 9) can be represented by each digit Base 2: two different numbers or states (0 & 1) can be represented by each digit (also called a bit) Eight (8) bits are also called a Byte Page 11
Digital Modulation (QAM Constellation Diagrams) Constellation Chart 16-QAM Constellation Chart 64-QAM States are closer together in 64-QAM it is more sensitive to noise Page 12
QAM Analysis (Tips) Tight clusters: Good Clean (Low Noise) transmission Large Open clusters: Additive Gaussian Noise Random Noise in transmission path Circular or Oval clusters: Phase Errors Discrete interference CTB or CSO Concentric Arc clusters: Phase Noise or Jitter Frequency and Phase variations on Recovered Carriers Transponders present in signal path Page 13
QAM Spectrum Management 35 30 25 20 15 10 5 0 QPSK Recommended (unequalized) MER for Digitally Modulated Carriers 8-PSK 16 QAM 32 QAM C/N figures are typically 6dB higher than UnEQ MER 64 QAM 128 QAM 256 QAM VoIP service considerations DOCSIS 2.0 has up to 128 QAM Clean node of 500 HP has 43 dbc C/N Combine 4 nodes or less (37 dbc C/N) Link availability critical Data service considerations Typically max @ 16 QAM, 3.2 MHz CH Used with both DOCSIS 2.0 & 1.1 BW allocated to customers dictates how many nodes are combined (64 max) Link availability Very important Telemetry applications Relegate them to the 5 to 14 MHz spectrum Typically operate in QPSK (more robust) Link availability important Future MER/CNR requirements 512 QAM will need 36/42 dbc 1024 QAM will need 39/45 dbc. Just at the limit of Video channels running at full power Page 14
Digital Off-Air Modulation (8-VSB) The world is switching to Digital Off-Air Broadcasts 2006: Luxembourg, The Netherlands 2007: Findland, Andorra, Sweeden, Norway, Switzerland 2008: Belgium, Germany 2009: USA 2011: Japan, Canada 8-level Vestigial SideBand Modulation Used in US terrestrial Digital TV ATSC transmission AM transmission (amplitude) with phase information in one of the sidebands. 8 phases with 3 bits/phase Reduced to 2 bits in the receiver Other sideband is suppressed and a pilot carrier is inserted to help receivers acquire the signal. Digital Modulation Format comparison: 8-VSB information exists in Amplitude only, fixed Phase slots (Off-Air) QAM information exists in both Amplitude & Phase variations (Cable) Page 15
HDTV (8VSB vs. QAM) Page 16
Digital Headend Terminology ASI Asynchronous Serial Interface (SMPTE 310M) MPEG Transport Stream (one or several programs) 19.4 to 38.8 Mbps (Compressed) SDI Serial Digital Interface (SMPTE 259M) Transporting Raw Digital Video and Audio Data 270 Mbps (Uncompressed) PSIP Program and System Information Protocol Collection of tables within a Transport Stream (TS) Describe the information at the system and event levels for all virtual channels. IRT Integrated Receiver Transcoder Receives QPSK, outputs QAM IF Transrating The process of reducing the bit rate of a digital signal (MPEG) Multiplexer The device that combines several Transport Streams into one S/PDIF Sony/Phillips Digital InterFace Used for Digital Audio connectivity in Home Theaters YPbPr Also called Component Video or Yipper cables Derived from RGB (Red-Green-Blue) Y carries Luma (brightness) and sync information Pb is the difference between Blue and Luma (B Y) Pr is the difference between Red and Luma (R Y) HDMI High Definition Multi-media Interface Carries Digital Video and Audio between Hi-Fi components Equivalent of S/PDIF plus YPbPr in one cable Page 17
HDTV (Data Rates) HDTV 1080i60 Bit Rate 1080i x 1920 pixels = 2,073,600 pixels 3 colors x 8 bits each = 24 bits/pixel One Full Frame = 49,766,400 bits/frame 30 frames/second = 1,492,992,000 bps SMPTE 274M (1.5 Gbps) Uncompressed 19.4 Mbps HDTV (1080i60) Compressed HDTV 720p60 Bit Rate 720p x 1280 pixels = 921,600 pixels 3 colors x 8 bits each = 24 bits/pixel One Full Frame = 22,118,400 bits/frame 60 frames/second = 1,327,104,000 bps SMPTE 274M (1.5 Gbps) Uncompressed 17.6 Mbps HDTV (720p60) Compressed HDTV 720p30 Bit Rate 720p30 x 1280 = 663,552,000 bps SMPTE 296M Uncompressed 8.8 Mbps HDTV (720p30) Compressed Standard Definition 480i60 480 x 704 = 243,302,400 bps SDI SMPTE 259M(270 Mbps) Uncompressed 3.75 Mbps SDTV (480i) Compressed CATV Digital Broadcasts Compressed 64 QAM (25.9 Mbps) 1080i + 480i 64 QAM (25.9 Mbps) 720p + 2x480i 256 QAM (36.6 Mbps) 720p + 720p 256 QAM (36.6 Mbps) 1080i + 720p(tr) 256 QAM (36.6 Mbps) 1080i + 4x480i Page 18
Bit Rate Bits per second carried across a channel Symbol Rate / Bit Rate phone line, serial cable or satellite transponder, for example PC s Serial Ports are 115,200 bps Baud Rate Data (words) sent within the channel Rate of delivery mostly related to the clock Example: 1) A modem sends information at 50 baud using 2 states (1 & 0) One bit (state) at a time Baud Rate is 50 baud (1 state per second) Bit Rate is 50 bps 2) The same modem at 50 baud, but now using 4 states, in pairs (00, 01, 10 & 11) Two bits at a time (various combinations of the four states or symbols) Baud rate is 50 baud (50 state pairs per second) Bit rate is 100 bps Page 19
Digital TV (Transport Standards) SMPTE (Society of Motion Picture and Television Engineers) SMPTE 260: (Legacy) 1125 lines/frame, 1035 active 2:1 interlaced with a 30 Hz or (30/1.001) Hz Frame rate SMPTE 259M: (European) 1250 lines/frame, 1080 active 2:1 interlaced with a 25 Hz Frame rate SMPTE 274M: (Various) 1125 lines/frame, 1080 active, progressive and interlaced at a variety of rates SMPTE 296M: (North American) 750 lines/frame, 720 active progressive with a 60Hz or (60/1.001) Hz Frame rate SMPTE 310M: MPEG-2 TS (Transport Stream) Used for point-to-point transport @ 19.4 or 38.8 Mbps NTSC friendly rates: 30/1.001 = 29.97 & 60/1.001 = 59.94 Page 20
MPEG (Compression) MPEG (Motion Picture Experts Group) International standard for compressing video MPEG-1: lower-resolution images ~ 1.5 Mbps Video-conferencing Desktop video applications mostly MPEG-2: Typically running 2.5 to 5 Mbps Television for home entertainment Officially adopted by ISO (ISO 13818-1) CATV delivery or IPTV delivery MPEG-4: based on MPEG-1, MPEG-2 & Apple QuickTime MPEG-4 files are smaller than JPEG or QuickTime files Uses narrower bandwidth (about 30% to 50% less than MPEG-2) MPEG-4: AVC (Advanced Video Coding), Part 10 (ISO/IEC 14496-10), and H.264 (ITU-T) are all essentially the same thing. MPEG-4 was standardized in October 1998 (ISO/IEC document 14496) Used in CATV or IPTV delivery Page 21
DVB vs ATSC Digital Video Broadcast Based upon MPEG-2 video and audio Covers satellite, cable and terrestrial broadcasts, system information, program guide, scrambling system Exceptions USA, Mexico, Canada, South Korea and Taiwan DVB-S (Satellite) DVB-S2 (2 nd Generation Satellite) DVB-C (Cable) DVB-T (Terrestrial) Supports HDTV Advanced Television Systems Committee Developed in the 1990 s by the Grand Alliance Replaced NTSC in USA (2009), next is Canada (2011), then Mexico (2021) DCII and ATSC use a modified version of the MPEG-2 video specification Claim better signal acquisition time. ATSC uses Dolby AC3 for audio AC3 and Musicam have the same BW for 5.1 audio, and perform about the same Supports HDTV Page 22
Digital Video Compression Digital Compression The picture (frame) is divided into blocks, and these blocks are evaluated for color variations & movement between frames. Using various calculations and algorithms, only the information that is different is sent forth between the full frame transmissions. Blocks that only have one color are mathematically reduced Blocks that do not move are mathematically reduced Blocks that move as they are to another location are mathematically reduced With MPEG-2 compression: a good quality picture (SD) can be achieved with the following data rates: For Action movies and Sport programs 5 Mbps is recommended Newscasts can be effectively transmitted with 2.5 to 3 Mbps More static programs use even less bandwidth Page 23
Digital Compression Frame Types: during digital encoding and compression different types of pictures are created: I-frames: contain only Intra macroblocks coded with information about the picture itself at that moment in time. must have at least one I-frame every 15 frames (or half a second) I-frames are used for synchronization in Ad Insertion, A/V alignment, etc. p-frames: contain predicted macroblocks made of either Intra or predicted material based on previous pictures. data is either image related, motion vector displacements or a combination of both. use less bits than I-pictures b-frames: contain bi-predictive pictures made of either Intra, predicted or bi-predicted macroblocks. uses other frames to average motion vectors of regions references frames cannot be other b-frames. use less bits than either I or p frames. Page 24
MPEG (Frame Types) b-frame p-frame I-frame 0 sec GOP Group Of Pictures 0.5 sec Page 25
Digital Compression (I-Frames) Macroblocks in the most of the sky around the Superhero do not change Macroblocks in the underside of the cape do not change Macroblocks in the body suit do not change Macroblocks in the face do not change Page 26
Digital Compression (p-frames) In this particular example only 13% of the information is being sent With Compression, the amount of information that needs to be sent to update the picture is greatly reduced. Page 27
Digital Compression 5 Mbps 2.5 Mbps 1.5 Mbps Page 28
Statistical Multiplexing Receiver Transcoder DHEI 26.97 Mbps Off-Air Rx: 8VSB ASI 9.39 Mbps Closed-Loop Statistical Multiplexing 50.0 45.0 Constant Bit-Rate Multiplexing 3.2 3.6 40.0 40.0 5.5 35.0 35.0 4.0 Sat Rx: MD ASI 38.8 Mbps Transrating-MUX Data Rate (Mbps) 30.0 25.0 20.0 15.0 10.0 Data Rate (Mbps) 30.0 25.0 20.0 15.0 10.0 4.1 5.0 5.3 4.0 5.7 5.0 5.0 9.2 0.0 1 2 3 4 5 6 7 8 9 10 Prog 1 Prog 2 Prog 3 Prog 4 Prog 5 Prog 6 Prog 7 Prog 8 Prog 9 Prog 10 0.0 1 2 3 4 5 6 7 8 9 10 Prog 1 Prog 2 Prog 3 Prog 4 Prog 5 Prog 6 Prog 7 Prog 8 Prog 9 Prog 10 Total bit rate using StatMUX 35 Mbps Total bit rate using peak CBR values 50 Mbps Page 29
Forward Error Correction Satellite transponders are noisy and subject to a large number of errors Transmitter sends error correction information along with actual signal, so receiver can re-generate the bit stream Two forms of error correction Convolutional Reed-Solomon code Interleaving Scrambling FEC Page 30
FEC (Types) Convolutional Coding with the Viterbi algorithm Code is quoted as a fraction, for example (2/3) means: (2/3) of symbol rate used for real data (1/3) remainder used for error correction purposes Reed-Solomon Used as an additional layer of error correction (besides Convolutional) 188 bytes out for every 204 bytes are data 16 bytes are parity bits to correct any remaining errors (about 7.84%) Page 31
FEC (Interleaving) Interleaving Original Message This is a sample message After interleaving ets haais mgi smeaesp l If an error occurs and wipes out the mgi part of the transmission; after de-interleaving we get: This *s a sa*ple messa*e Only single characters are missing (*) rather than an entire word, making the message easier to understand (recover) Page 32
FEC (Scrambling) Scrambling Final step of error correction scheme Ensures that long runs of the same symbol value do not occur Lack of change in phase of the carrier would lead to loss of clock QPSK Demodulator obtains its signal clock directly from the signal Large numbers of phase changes are needed in order to re-generate the clock This form of scrambling is not the same as scrambling used for Access Control purposes 0000000000000011111111111111110000000000000111111111110101010101010101010101 0000100001000001111011110111100000100001000101111011111101000101110101010111 Page 33
Cable Spectrum @ Head End Return Path Levels defined by band loading, type of lasers @ Nodes, and individual service BW Analog TV Typically 70 channels running at levels of +60 dbmv Digital TV 256 QAM running 10 db below Analog Digital TV 64 QAM running 6 db below Analog Data Services 64 or 256 QAM Levels determined by minimum requirement on CPE s AGC Pilot FM Band RET 5 40 ANALOG VIDEO DIGITAL VIDEO SD & HDTV INTERACTIVE 52 550 650 750 870 Page 34
CATV HE (Analog + Digital Video Simulcast) Sat Rx: P1 Sat Rx: P2 Encoder VBR 98x A/V Analog HE 98 NTSC Channels Sat Rx: P97 Sat Rx: P98 98x A/V DA Encoder VBR Encoder VBR Encoder VBR MPEGoIP (4 Mbps) 10/100 HFC Network MB Media Network Sat Rx: P99 ASI-SPTS x 24 Media Converter Gig-E QAM RF 12x STB Sat Rx: P123 Gig-E Sat Rx: MD P124-130 Sat Rx: MD P131-136 ASI-MPTS Transrating-MUX QAM RF 8x VPN Terminal Device Manager Subs Data Server Out of band Mod STB Data Network Encryption Key Gen Local Controller Interactive Apps Server Return Demod STB Page 35
CATV HE (Ad Insertion) Sat Rx: P1 Sat Rx: P2 Sat Rx: P97 DA Encoder VBR Encoder VBR Encoder VBR MPEGoIP (4 Mbps) 10/100 Ads Manager Traffic & Billing Sat Rx: P98 98x A/V Encoder VBR SCTE-35 Embedded in MPEG Encoder Ingest Media Network Sat Rx: P99 Gig-E ASI-SPTS x 24 Media Converter Sat Rx: P123 Ad Server 12x DTMF/GPI 12x SPTS (ads) Gig-E QAM RF 12x Sat Rx: MD P124-130 SCTE-30 Splicer Control Sat Rx: MD P131-136 ASI-MPTS Transrating-MUX SCTE-30 DPI Messages Data Network Page 36
CATV HE (VoD) Billing System VoD Server HFC Network MB Media Network Sat Rx: MD P124-130 VoD Satellite Feeds STB Transrating-MUX QAM RF 12x VPN Terminal Device Manager Subs Data Server Out of band Mod Data Network STB Encryption Key Gen Local Controller Interactive Apps Server Return Demod STB Page 37
CATV HE (Signal Types) L-band QPSK 8PSK 16/32APSK Satellite Receiver DigiCipher II, PowerVu, Irdeto, Director, Compel, CAS-5000, BISS, etc. A/V A/V Modulator NTSC Encoder A/V NTSC STB SDI Encoder SDI MPEGoIP ASI-SPTS ASI-MPTS Gig-E ASI-SPTS ASI-SPTS ASI-SPTS MPEGoIP Media Converter Gig-E Gig-E 256QAM STB Transrating-MUX QAM RF Modulator 64QAM STB Page 38
Digital Video Processing (Signal Chains) QAM/8VSB ATSC/QAM Transcoder QAM ASI 1 MUX QAM Modulator QAM ATSC/QAM Demodulator A/V ASI 2 Digital to Analog Processor NTSC-RF ASI Agile QAM Modulator QAM Digital to Analog Decoder A/V Modulator NTSC-RF HDMI HDMI to QAM Encoder QAM Multi-Processor ASI Gig-E NTSC w/ AFD Analog Audio BTSC 4.5 MHz Audio Carrier Page 39
Digital Video Processing (Legacy Signal Chains) L-Band Rx Decrypt- Extract Module Encrypt- Insert Module QAM-64/256 Upconvert IRT-2000 C8U L-Band Rx Decrypt- Extract Module Encrypt- Insert Module QAM-64/256 Upconvert IRT-2000 IRT-2000 + C8U: Decrypt 24 DigiCipher II (QPSK) / Encrypt 24 MediaCipher (QAM) [5RU] MPS-B4 + C8U: Decrypt 36 DigiCipher II (QPSK) / Encrypt 36 MediaCipher (QAM) [6RU] Page 40
Digital Video Processing (Digital Turnaround) Digital Turnaround: DSR-4400MD + SEMv8: Decrypt 48 DigiCipher II (QPSK) / Encrypt 48 MediaCipher (QAM) [3RU] Page 41
MPEG Processing (Transrating MUX) Network Multiplexer Set min/max bit rate & recoding priorities Digital ad insertion PID filtering/re-mapping PCR de-jitter/re-stamping PAT and PMT computation and insertion SI and PSI processing ATSC (PSIP) aggregation & StatMUX pools CBR to VBR and VBR to CBR conversion SD/HD rate shaping Page 42
Jitter Clean Eye Diagram Jitter The term used to describe the periodic or random deviations of digital signal transitions compared to a reference clock Closed Eye Diagram with severe Jitter Page 43
Time Servers (Product Comparison) Oscillator Holdover Drift TCXO 18 ms/day OCXO 1 ms/day Rubidium <.01 ms/day GPS Atomic Clock reference ± 10 ns Page 44
CATV Digital STB s Page 45
IPTV (STB Comparative Features Table) Page 46
IPTV (Hospitality Solutions) Time-Shifted TV Guest services e-commerce On-Demand Movies HDTV NPVR Games Page 47
Test Equipment (What do you test?) Triple-Play Voice Data Video What are your core service offerings? PSTN VoIP DATA (Internet Service) IP Video RF What infrastructure do you have to support? Access Network Fiber xdsl CABLE OLT PON Plant ONU (FFTx) VDSL ADSL2+ Coax CATV ONT (FFTP) ADSL2+ VDSL In-Home Distribution Networks What quality of service do you need to offer? What is your competition doing? Are there government regulations to meet? Do you have to provide regular POP reports? HPNA MoCA Ethernet Wireless Home Plug Page 48
감사하십시오 Merci Dank u Danke ありがとう Gracias Advanced Media Technologies Director Technical Sales (954) 427-5711 (954) 605-5094 Ευχαριστώ Спасибо Obrigado Grazie Thank you Page 49