Broadcast Day SSPI - 2007

1. Broadcast Day SSPI - 2007 Carlos Capellão

2. Linha de Produtos PHASE

3. IP as Connectivity – Is IP Replacing ASI?

4. 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. ASI Versus Gigabit Ethernet Physical

6. 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. Buffer RF Transport Packets ASI Clock More Complex Algorithm Clock Recovery Larger Buffer Required Time stamps Buffer Fullness Buffer RF Transport Packets Ethernet Modulation Modulation Clock Clock Recovery Time stamps Buffer Fullness Timing Recovery

8. Buffer Level Decoder starts playing VBV Time I B B P B B P B B P B B P T=0, decoder starts receiving data Decoder Playback Process (ASI)

9. Buffer Level Decoder starts playing VBV Time I B B P B B P B B P B B P Packet Reception Times T=0, decoder starts receiving data Decoder Playback Process (Ethernet)

10. 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. 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. Ethernet Port Ethernet Port Ethernet Port Ethernet Port Non-Blocking Switch Fabric 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.

13. Switch 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!! 6 Mb/s Data Source Link Capacity: 10 Mb/s Data Source 6 Mb/s 2 Mb/s Packet Loss

14. 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. 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. 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. ASI ASI ASI ASI ASI ASI Video Source Video Source Video Source ASI Switch $$$$$ Modulator Decoder Modulator Decoder Modulator Decoder Required since Transport packets do not carry addresses Control Terminal ASI Interconnect

18. Ethernet Ethernet Ethernet Ethernet Ethernet Ethernet Video Source Video Source Video Source Ethernet Switch cheap Modulator Decoder Modulator Decoder Modulator Decoder Control is not required since each packet contains an address!! IP Interconnect

19. IP Technology – Bits and Pieces

20. 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. 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. 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. 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. TT1260: MPEG-2 SD 4:2:2 TT1222: MPEG-2 SD 4:2:0 TT1280/2: MPEG-2 HD RX1290: Everything

24. MX8400 Mediaplex iPlex Process: Multiplexers and Demultiplexers • Capable of multiplexing and demultiplexing IP flows. • Extensive set of (P)SI table generation options • Functions also available on ASI. • High-end multiplexer, GE inputs and outputs • Scrambling also available

25. Mediaplex iPlex 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

26. Mediaplex iPlex 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.

27. 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. Obrigado! Carlos Capellão capellao@phase.com.br Tel. 21.2493.0125