11
Broadcast Day SSPI - 2007Broadcast Day SSPI - 2007
Carlos CapellãoCarlos Capellão
22
Linha de Produtos PHASELinha de Produtos PHASE
IP as Connectivity – Is IP Replacing ASI?
www.tandbergtv.com
Introduction
• We will discuss ASI versus IP for digital video
connectivity.
• For IP, we will really c...
www.tandbergtv.com
ASI Versus Gigabit Ethernet Physical
Parameter ASI Gigabit Ethernet
Line Bit Rate 270 Mb/s 1.25 Gb/s
Li...
www.tandbergtv.com
Physical Layer Notes
• Gigabit Ethernet is always switched
– No contention
– Always full-duplex
• ASI i...
www.tandbergtv.com
Timing Recovery
Buffer
Modulation
Clock
Recovery
RF
Clock
Time stamps
Buffer Fullness
Transport
Packets...
www.tandbergtv.com
Decoder Playback Process (ASI)
Buffer
Level
Time
VBV
T=0, decoder
starts receiving data
Decoder starts ...
www.tandbergtv.com
Decoder Playback Process (Ethernet)
T=0, decoder
starts receiving data
Decoder starts playing
Buffer
Le...
www.tandbergtv.com
Conclusions so far…
• From a physical layer point of view, ASI and
Ethernet are very similar
– Point-to...
www.tandbergtv.com
The Packet Loss “Issue”
• Let’s look first at a point-to-point connection with
a crossover cable.
• The...
www.tandbergtv.com
Ethernet Switches
• All modern switches are non-blocking and can
operate at line rate.
• Transmit and r...
www.tandbergtv.com
Where is the Packet Loss, then?
• Packet loss happens when a link is
oversubscribed – more traffic than...
www.tandbergtv.com
Packet Loss Notes
• Packet loss happens when there is congestion in
the network.
• Short-term congestio...
www.tandbergtv.com
Dealing with Occasional Packet Loss
• Occasional packet loss, for whatever reason, can
be handled by FE...
www.tandbergtv.com
IP Advantages over ASI
• We have seen that, from a transport point of
view, IP and ASI are fairly equiv...
www.tandbergtv.com
ASI Interconnect
Video
Source
ASI Modulator
Decoder
ASI
Video
Source
ASI
Video
Source
ASI
Modulator
Dec...
www.tandbergtv.com
IP Interconnect
Video
Source
Ethernet Modulator
Decoder
Ethernet
Video
Source
Ethernet
Video
Source
Eth...
IP Technology – Bits and Pieces
www.tandbergtv.com
Ingress: Encoders
• All Tandberg Encoders either have IP output built
in (iPlex, Mediaplex) or offered ...
www.tandbergtv.com
Encoders at a Glance
• EN Series (single channel) SDTV/HDTV – MPEG2/MPEG4
– EN5710/5720: MPEG-2 Standar...
www.tandbergtv.com
Network Interfaces and Protocols
• Interfaces:
– EN Series:
• Dual copper Gigabit Ethernet Interfaces
–...
www.tandbergtv.com
Receivers at a Glance
• All Tandberg Receivers include a Professional Decoder
• Receivers have a variet...
www.tandbergtv.com
Process: Multiplexers and Demultiplexers
• Capable of multiplexing
and demultiplexing IP
flows.
• Exten...
www.tandbergtv.com
Process: Rate Shaping
• Rate Shaping: Converting a service
from one bit rate to another
– To fit in a b...
www.tandbergtv.com
Process: MPEG-2 to H.264 Conversion
• Most existing content from
broadcasters comes in as MPEG-2.
• In ...
www.tandbergtv.com
Conclusions
• There are devices available for the entire digital
video processing chain that can use an...
www.tandbergtv.com
Obrigado!
Carlos Capellão
capellao@phase.com.br
Tel. 21.2493.0125
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Broadcast day-2007-tandberg-ipxasi

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Broadcast day-2007-tandberg-ipxasi

  1. 1. 11 Broadcast Day SSPI - 2007Broadcast Day SSPI - 2007 Carlos CapellãoCarlos Capellão
  2. 2. 22 Linha de Produtos PHASELinha de Produtos PHASE
  3. 3. IP as Connectivity – Is IP Replacing ASI?
  4. 4. www.tandbergtv.com Introduction • We will discuss ASI versus IP for digital video connectivity. • For IP, we will really concentrate on Gigabit Ethernet. • We will discuss: – Physical layer implementation – Timing features – Packet loss issues – Routing of traffic • And we will conclude that IP is a good replacement for ASI!
  5. 5. www.tandbergtv.com ASI Versus Gigabit Ethernet Physical Parameter ASI Gigabit Ethernet Line Bit Rate 270 Mb/s 1.25 Gb/s Line Coding 8B/10B (based on Fiber Channel) 8B/10B (based on Fiber Channel) Information Bit Rate 216 Mb/s 1.0 Gb/s Link Type Unidirectional point-to-point Dual-Unidirectional point-to-point When to transmit? Whenever I want Whenever I want Byte Synchronization Sends sync pattern when idle Silence when idle, 8-byte sync before packet Frame check None (Reed- Solomon optional) CRC
  6. 6. www.tandbergtv.com Physical Layer Notes • Gigabit Ethernet is always switched – No contention – Always full-duplex • ASI interfaces typically transmit at a constant bit rate, hardware-metered • ASI interfaces are unidirectional • Gigabit Ethernet interfaces are always composed of two unidirectional interfaces, one on each direction
  7. 7. www.tandbergtv.com Timing Recovery Buffer Modulation Clock Recovery RF Clock Time stamps Buffer Fullness Transport Packets ASI Modulation Clock Recovery RF Clock Time stamps Buffer Fullness Transport Packets Ethernet Buffer Larger Buffer Required More Complex Algorithm
  8. 8. www.tandbergtv.com Decoder Playback Process (ASI) Buffer Level Time VBV T=0, decoder starts receiving data Decoder starts playing I B B P B B P B B P B B P
  9. 9. www.tandbergtv.com Decoder Playback Process (Ethernet) T=0, decoder starts receiving data Decoder starts playing Buffer Level VBV Time I B B P B B P B B P B B P Packet Reception Times
  10. 10. www.tandbergtv.com Conclusions so far… • From a physical layer point of view, ASI and Ethernet are very similar – Point-to-point packet transport mechanism • Ethernet always has a CRC so bit errors can be detected – With ASI, even if configured for 204-byte mode (Reed- Solomon), the great majority of the equipment does not generate or check it – that is done by modulators and demodulators. • Differences in packet timing are very manageable • But … what about packet loss???
  11. 11. www.tandbergtv.com The Packet Loss “Issue” • Let’s look first at a point-to-point connection with a crossover cable. • There is no contention, no buffering – it is almost the same as having two ASI connections, one in each direction. • The only way a packet can be dropped is if the receiver drops it – and that is not going to happen (by design)!
  12. 12. www.tandbergtv.com Ethernet Switches • All modern switches are non-blocking and can operate at line rate. • Transmit and receive channels are independent. • Switches also have a certain amount of buffering. Ethernet Port Ethernet Port Non-Blocking Switch Fabric Ethernet Port Ethernet Port
  13. 13. www.tandbergtv.com Where is the Packet Loss, then? • Packet loss happens when a link is oversubscribed – more traffic than its capacity. • Switch will buffer instantaneous bursts, but cannot buffer forever. • Solution: don’t do it!! Switch Data Source Data Source Link Capacity: 10 Mb/s 6 Mb/s 6 Mb/s 2 Mb/s Packet Loss
  14. 14. www.tandbergtv.com Packet Loss Notes • Packet loss happens when there is congestion in the network. • Short-term congestion introduces jitter (as packets are buffered); long-term congestion introduces packet loss. • Congestion is avoided by properly designing the network capacity for the traffic. • Good news is that, unlike data, digital video capacity requirements are well-known and easy to design for. • If you want to mix video and data in the same network, high-end routers and switches can be configured to give priority to video.
  15. 15. www.tandbergtv.com Dealing with Occasional Packet Loss • Occasional packet loss, for whatever reason, can be handled by FEC. – Slightly different from the traditional FEC – we rebuild “lost” bits instead of “correcting” wrong bits. • Standardized FEC options: – RFC 2733: “Row” FEC. – Pro-MPEG FEC: “Column” and “Row” FEC, can handle burst losses. • FEC is supported in most Tandberg equipment and interoperates with equivalent implementations from third-party vendors – Interop demonstrated in VSF meeting in Orlando last January.
  16. 16. www.tandbergtv.com IP Advantages over ASI • We have seen that, from a transport point of view, IP and ASI are fairly equivalent, with a small advantage in favor of IP (FEC). • As a system interconnect solution, IP has two major advantages over ASI: – IP has a network layer: IP packets contain routing information, indicating where they should go. That includes IP multicast – one-to-many delivery. – IP equipment is universal, and there are many vendors to choose from – high volume items, very cost- effective.
  17. 17. www.tandbergtv.com ASI Interconnect Video Source ASI Modulator Decoder ASI Video Source ASI Video Source ASI Modulator Decoder ASI Modulator Decoder ASI ASI Switch $$$$$ Control Terminal Required since Transport packets do not carry addresses
  18. 18. www.tandbergtv.com IP Interconnect Video Source Ethernet Modulator Decoder Ethernet Video Source Ethernet Video Source Ethernet Modulator Decoder Ethernet Modulator Decoder Ethernet Ethernet Switch cheap Control is not required since each packet contains an address!!
  19. 19. IP Technology – Bits and Pieces
  20. 20. www.tandbergtv.com Ingress: Encoders • All Tandberg Encoders either have IP output built in (iPlex, Mediaplex) or offered as an option (EN series) EN Series iPlex Mediaplex
  21. 21. www.tandbergtv.com Encoders at a Glance • EN Series (single channel) SDTV/HDTV – MPEG2/MPEG4 – EN5710/5720: MPEG-2 Standard Definition – EN5770/5775: MPEG-2 Standard Definition Dual-Pass – EN5780/5782: MPEG-2 High Definition – EN5920: Windows Media/VC-1 Standard Definition – EN5930: H.264 Standard Definition – EN5980: Windows Media/VC-1 High Definition – EN5990: H.264 High Definition – EN8030: Second Generation H.264 Standard Definition – EN8090: Second Generation H.264 High Definition • Mediaplex, iPlex (multiple channel) – MPEG-2 Standard Definition Submodule (up to 48 in the Mediaplex, up to 8 in the iPlex) – H.264 Standard Definition (up to 48 in the Mediaplex, up to 8 in the iPlex) – H.264 Second Generation Standard Definition (up to 4 in the iPlex, Mediaplex support planned). – H.264 High Definition (up to 4 in the iPlex, Mediaplex support planned)
  22. 22. www.tandbergtv.com Network Interfaces and Protocols • Interfaces: – EN Series: • Dual copper Gigabit Ethernet Interfaces – iPlex: • Dual Gigabit Ethernet (SFP – fiber and copper available) – Mediaplex • Four Gigabit Ethernet Interfaces (multimode fiber) – Mediaplex/iPlex also support optional ATM OC-3, DS-3 and E-3 interfaces. • Protocols: – UDP – RTP – Forward Error Correction
  23. 23. www.tandbergtv.com Receivers at a Glance • All Tandberg Receivers include a Professional Decoder • Receivers have a variety of available input front-ends (including IP), optional descrambler, and an ASI output • The TT1222 includes an IP output option. TT1222: MPEG-2 SD 4:2:0 TT1260: MPEG-2 SD 4:2:2 TT1280/2: MPEG-2 HD RX1290: Everything
  24. 24. www.tandbergtv.com Process: Multiplexers and Demultiplexers • Capable of multiplexing and demultiplexing IP flows. • Extensive set of (P)SI table generation options • Functions also available on ASI. Mediaplex iPlex MX8400 • High-end multiplexer, GE inputs and outputs • Scrambling also available
  25. 25. www.tandbergtv.com Process: Rate Shaping • Rate Shaping: Converting a service from one bit rate to another – To fit in a bandwidth-limited channel – Convert to CBR for video servers • Function provided by the Media Processor submodule in iPlex/Mediaplex – Mediaplex: support for approximately 144 services. – iPlex: support for approximately 36 services. – Actual number depends on bit rate • Inputs and outputs can be IP streams Mediaplex iPlex
  26. 26. www.tandbergtv.com Process: MPEG-2 to H.264 Conversion • Most existing content from broadcasters comes in as MPEG-2. • In some installations, it may be desirable to convert it to H.264. • The Media Processor submodule in the iPlex/Mediaplex can provide this function. • Capacity: – Mediaplex: 48 services – iPlex: 8 services • Inputs and outputs can be IP streams. Mediaplex iPlex
  27. 27. www.tandbergtv.com Conclusions • There are devices available for the entire digital video processing chain that can use an IP network as the interconnection method. • This IP interconnect can be restricted to the head-end or can extend all the way to the consumer set-top box. • IP interconnects can be used in traditional digital video architectures (digital cable, satellite) inside the head-end, while maintaining the same egress method. • Tandberg Television has all the “bits and pieces” required to make this work!
  28. 28. www.tandbergtv.com Obrigado! Carlos Capellão capellao@phase.com.br Tel. 21.2493.0125

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