1. Maximizing Satellite Transmission Efficiency With DVB-S2
Gidi Raz

2. Agenda
The Challenge
What is DVB-S2
DVB-S2 New Tools & Technologies
DVB-S2 Business Model

3. Transmission costs (1.5-2M$ / 36 Mhz / Year)
The Challenge
Transmission costs (1.5-2M$ / 36 Mhz / Year)
Increasing number of channels
Moving to HD – High bandwidth consumer
Reduce OPEX / CAPEX
Limitations in current DVB-S and DVB-DSNG

4. So what do we need?
Increased data throughput in a given bandwidth, or
Use less satellite capacity and save money
Increased availability through improved link margin – More robust
Increased coverage area
Smaller dish
DVB-S2
Moving to S2 enables more content on the same spectrum
More robust in aspect of delivery quality
Increases foot print
Require smaller dishes

5. What is DVB-S2 ?
New DVB standard for digitial satellite communications
Up to 30% bandwidth saving
Up to 2.5 dB margin gain
Meant to replace DVB-S & DVB-DSNG
New features such as:
Support of multiple streams on a single carrier
Variable and Adaptive Coding and Modulation
Much better spectral efficiency
So close to the Shannon limit that it could be the last DVB-S standard!
Shannon's Law
Expresses the maximum possible data speed that can be obtained in a data channel.
Shannon's Law says that the highest obtainable error-free data speed, expressed in
bits per second (bps), is a function of the bandwidth and the signal-to-noise ratio

6. Short Example
Using 36Mhz transponder using different modulation and compression scheme
- Shannon limit - maximum possible data speed that can be obtained in a data channel

7. DVB-S2 Applications
Broadcast Services- digital multi-programme Television (TV) / High Definition Television (HDTV) broadcasting services to be used for primary and secondary distribution in Fixed Satellite Service (FSS) and Broadcast Satellite Service (BSS) bands. (Including compatibility to MPEG-4)
Digital TV Contribution and Satellite News Gathering (DTVC/DSNG)
Interactive Services- Interactive data services including Internet access (only the forward broadband channel)
Data content distribution/trunking and other professional applications (only the forward broadband channel)

8. DVB-S2 Why the new system?
2.5dB = 33% more useful data rate, or 2.5m Vs. 4.5m antenna
Shannon limit
DVB-S2
DVB-S & DSNG
- Shannon limit - maximum possible data speed that can be obtained in a data channel
2.5 dB margin gain
signal-to-noise ratio

9. DVB-S2 and Broadcast applications (DTH)
Typical 36MHz transponder usage with DVB-S and DVB-S2:
SATELLITE EIRP 51 dBW
SATELLITE EIRP 53.7 dBW
DVB-S
DVB-S2
DVB-S
DVB-S2
Symbol Rate
Roll-Off factor
27.5 Mbauds
(ROF 0.35)
30.9 Mbauds
(ROF 0.20)
27.5 Mbauds
(ROF 0.35)
29.7 Mbauds
(ROF 0.25)
Modulation
QPSK 2/3
QPSK 3/4
QPSK 7/8
8PSK 23
Bit rate
33.8 Mbps
46 Mbps (+36%)
44.4 Mbps
58.8 Mbps (+32%)
Number of SD channels
7 SDTV MPEG2
15 SDTV h.264
10 SDTV MPEG2
21 SDTV h.264
10 SDTV MPEG2
20 SDTV h.264
13 SDTV MPEG2
26 SDTV h.264
Example for utilization of S Vs. S2 modulation on 36 MHz transponders
Number of HD channels
1 HD MPEG2
3 HD h.264
2 HD MPEG2
5 HD h.264
2 HD MPEG2
5 HD h.264
3 HD MPEG2
6 HD h.264

10. DVB-S2 SYSTEM Tools
Powerful FEC system based on LDPC (Low-Density Parity Check) codes
Wide range of code rates (from 1/4 up to 9/10)
New Modulation schemes ranging from 2 to 5 bit/second/Hz spectrum efficiency - QPSK, 8PSK, 16APSK, 32APSK
Set of three spectrum shapes with roll-off factors 0.35, 0.25 and 0.20
Flexible stream adapter, suitable to operate with single and multiple TS on the same carrier with different modulation and FEC
Variable & Adaptive Coding and Modulation (VCM/ACM) functionality, allowing to optimise channel coding and modulation on a frame-by-frame basis.
The LDPC replaces the traditional Viterbi & Reed Solomon
Instead of limited code rates ½, 2/3, ¾ - enables more flexibility regarding the overhead required for FEC in very good condition you could use 1/9 FEC meaning adding one packet on each 9 packet for recovery, in bad conditions (storm) you could select ½ rate more meaning on each packet another packet for recovery.
three spectrum shapes – enable better utilization of the signal
Flexible stream adapter – enables different TS on the same carrier with different modulation scheam, different FEC

11. Three Spectrum Shapes 20%
three spectrum shapes – enable better utilization of the signal

12. DVB-S2 Modes and Options
3 standards in one:
Non Backward Compatible Broadcast
Backward Compatible Mode
Adaptive Coding and Modulation Option
Non Backwards – only IRD’s supporting S2 will work
Adaptive Coding – Enabling different coding & modulation on the same carrier
Backwards – Can support both S and S2

13. Non Backward Compatible
NBC Mode – Taking advantage of all S2 Capabilities
Specifies QPSK, 8PSK, 16APSK and 32APSK constellations
Uses a LDPC Block code (64kbit block size)
16 kbit block size as an option – for low delay mode
Coding performance within 1dB of Shannon limit
Many code rates from ¼ to 9/10
This mode will be used only when all the receivers supports S2 (Scopus solution for DSNG)
Taking the advantage of all S2 capabilities – non hierarchy mode

14. BCM - Backwards Compatible Mode
Sending, on a single Satellite channel, two Transport Streams - Hierarchical QPSK
HP (High Priority) DVB-S (QPSK) – modulate for DVB-S
LP (Low Priority) DVB-S2 (BPSK) ) – modulate for DVB-S2
Example: At QPSK ¾ it can add up to 17Mbps for new programs in DVB-S2. (36Mhz TP)
In this mode the modulator build the signal hierarchically, high priority channel is modulate for dvb-s for all receivers and low priority channel on the dvb-s2 maximizing the bandwidth usage
Non-uniform 8PSK constellation
Hierarchical QPSK

15. Variable & Adaptive Coding/Modulation
Option within the standard – not implemented yet
For interactive and one-to-one applications making use of return channels to provide the exact channel protection
Coding and Modulation can change on an FEC block basis
Mode is signalled by a header added to the front of each FEC block
It’s only in the standard, no one did it yet. It requires system support

16. New Modulation Constellations
QPSK
2 bits/symbol
8PSK
3 bits/symbol
Graphic presentation of the spectrum utilization using different modulation schemes.
QPSK – 2 Bits
8PSK – 3 Bits
16APSK – 4 Bits
32APSK – 5 Bits
16APSK
4 bits/symbol
32APSK
5 bits/symbol

17. Comparison of DVB-S2 and DVB-S
Subject
DVB-S
DVB-DSNG
DVB-S2
FEC
Reed-Solomon & Viterbi
LDPC
FEC rates
0.46 – 0.81
FEC Performance
2-2.5 dB better
Modulation
BPSK, QPSK
QPSK,8PSK,16QAM
QPSK,8PSK,16APSK,32APSK
Max Spectral Efficiency
1.61
3.22
4.44
Block size
~ 32Kbit
64Kbit , 16Kbit
Roll-off
0.35
0.35, 0.25
0.35, 0.25, 0.20
CCM/VCM/ACM
CCM
VCM/ACM (for IP data)
Implementation Complexity
Low
Medium
Very High
Stream adaptation
MPEG
MPEG & programmable

18. Three Operation Mode CCM Constant Coding and Modulation
All frames use the same (fixed) parameters
VCM Variable Coding and Modulation
Different streams/services are coded with different (fixed) parameters on the same carrier
ACM Adaptive Coding and Modulation
Each frame is coded with its own set of parameters. Parameters are modified dynamically according to the reception conditions for each receiver
CCM – when a transport stream is sent with fixed parameters
VCM – sending 2 streams with different modulation parameters over the same transponder
ACM – Each frame is coded with its own set of parameters. Parameters are modified dynamically according to the reception conditions for each receiver

19. Distribution of multiple TS multiplexes
DTT Transmitters
(Multiple TS, Constant Code Modulator - CCM)
DVB-S2 Modulator
Mode adapter
QPSK
Rate 5/6
DTT
MUX 1 1 SD
MERGER
Transport Stream 1
Stream
Adapter
FEC
Coder
Mod SD
DTT
MUX 2 2
Transport Stream 2 SD
Constant Coding & Modulation SD

20. Distribution of multiple TS multiplexes
Perfect fit for DVB-T distribution
2 Transport streams of 24 Mbps on single carrier (36 Mhz)
Can carry more than 30 Mpeg4/SD channels or 6-8 HD Channels

21. Applications- SDTV and HDTV broadcasting
2. Differentiated channel protection
(Variable Code Modulation, Multiple TS - VCM)
DVB-S2 Modulator
Mode adapter
QPSK
Rate 3/4
MUX 1 1 SD
MERGER
Transport Stream 1
Stream
Adapter
FEC
Coder
Mod SD
Two different streams with different modulation parameters are sent over the same transponder
MUX 2 HD 2
Transport Stream 2
16 APSK
Rate 3/4 HD

22. Applications 3. DSNG Services using ACM
(Single Transport Stream, information rate varying in time)
Using the return channel to adapt modulation and FEC

23. No ACM /VCM

24. With ACM and VCM

25. Business Models
Using the return channel to adapt modulation and FEC

26. Two Examples Contribution Distribution
Delivering 5 Mbps from point to point
DBV-S: QPSK ¾ , with roll off factor of 0.35 requires 4.88 Mhz
DBV-S2: QPSK 9/10 , with roll off factor of 0.2 requires 3.37 Mhz
Total bandwidth saving of 30%
Total cost saving is $70,000 a year (ROI 5 Months)
Distribution
Distribution of 10 channels to 10 location (average 3.5 Mbps/Ch.)
DBV-S: QPSK ¾ , with roll off factor of 0.35 requires Mhz
DBV-S2: QPSK 9/10 , with roll off factor of 0.2 requires Mhz
Total cost saving is $620,000 a year (ROI 5 Months)
This mode will be used only when all the receivers supports S2 (Scopus solution for DSNG)
Taking the advantage of all S2 capabilities – non hierarchy mode

27. Business Model - Contribution

28. Business Model - Distribution

29. Take advantage of the new technology Mpeg4 / DVB-S2
Summary
Take advantage of the new technology Mpeg4 / DVB-S2
Save at least 30% bandwidth / Money

30. Thank You