Date post: | 16-Jul-2015 |
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IN THIS PRESENTATION
• BROADCASTING
• DVB
• DVB-STANDARDS
• FREQUENCY BANDS
• BLOCK DIAGRAM OF DIGITAL NETWORK
• INTRODUCTION TO DVB-S, C, T
• DIFFERENT DEVICES USED IN DIGITAL
NETWORK
Broadcasting:
• In Telecommunication, broadcasting refers to a method of transferring a message to all recipients simultaneously
Digital Video Broadcasting (DVB)
• DVB is a set of standards that define digital broadcasting using existing satellite, cable, and terrestrial infrastructures.
• The term digital television is sometimes used as a synonym for DVB
DVB Standards
• DVB-S
• DVB-C
• DVB-T
• DVB-S2
• DVB-C2
• DVB-T2
Satellite Frequency Bands
• C-Band(4 to 8GHz)
• KU-Band(11 to 17GHz)
• KA-Band(20 t0 30GHz)
Receiver MUX
CombinerOptical TX
Free To Air Digital Channel Block ROSA SYSTEM
QAM
Receiver MUX
QAMCombinerOptical TX
Descrambler
Paid Channel Digital Block Diagram ROSA SYSTEM
Receiver Multiplexer QAM
IF Modulator
AudioVideo
IF outUp Converter
ASI OUT
ASI OUT
ASI =Asynchronous Serial Interface
Rf Combiner1550nm optical TX
More than one Channels with single receiver on Digital network
Dish
Single channel with single receiver on analog network
RF
RF
RF
To co-locations
QAM=Quadrature amplitude modulation
DVB-S
• DVB-S is an abbreviation for "Digital Video Broadcasting —Satellite“.
• It is the original Digital Video Broadcasting Forward error correction and demodulation standard for Satellite Television.
• Dates from 1995, in its first release, while development lasted from 1993 to 1997.
Frequency in Use by Nayatel
• Frequency range being used by Nayatel for receiving channels is 10.3GHz to 12.3GHz.
• Note: Communication spectrum for military can use upto 18GHz frequency.
DVB-S2Digital Video Broadcasting - Satellite - Second
Generation
• designed as a successor for the popular DVB-S system.
• Developed in 2003
• Impact2 and Impact4 Encoding Schemes are used to lessen the Bandwidth
• The development of DVB-S2 coincided with the introduction of HDTV and H.264 (MPEG-4 AVC)
Difference Between DVB-S, DVB-S2
• DVBS is basically SD (NOT HD) and DVBS2 is HD
• DVBS sends in MPEG2 (like what you find in DVD`s) and DVBS2 sends in MPEG4 which is a better compression algorithm
• DVB-S use QPSK as Modulation Mode while DVB-S2 uses QPSK, 8PSK, 16PSK modulation modes.
Improvements:
• In March 2014, DVB-S2X specification has been published by DVB Project
DVB-C(Digital Video Broadcasting –Cable)
• DVB European consortium standard for the broadcast transmission of digital television over cable.
• first published by the ETSI in 1994
• DVB-C (VHF/UHF) uses QAM: 16-QAM, 32-QAM, 64-QAM, 128-QAM or 256-QAM.
• transmits an MPEG-2 or MPEG-4 family digital audio/digital video stream
DVB-C2• Development announced in 2008
• The final DVB-C2 specification was approved by the DVB Steering Board in April 2009.
• DVB-C2 allows bitrates up to 83.1 Mbit/s on a 8 MHz channel bandwidth when using 4096-QAM
modulation.
• Future extensions will allow up to 97 Mbit/s and 110.8 Mbit/s per channel using 16384-QAM and
65536-AQAM modulation
• Muliplets Multiple Streams into Single Transport Stream.
• Only Lies for UHF
Being Used in Nayatel
• Nayatel is using 64QAM with 8MHz gap, using which total of 38.2Mbps of data can be streamed.
DVB-C DVB-C2
Input InterfaceSingle Transport Stream(TS)
Multiple Transport Stream and Generic Stream Encapsulation(GSE)
ModesConstant Coding &Modulation
Variable Coding & Modulation and Adaptive Coding & Modulation
FECReed Solomon (RS)
LDPC + BCH 1/2, 2/3, 3/4, 4/5, 5/6, 8/9, 9/10[4]
ModulationSingle Carrier QAM
absolute OFDM[5]
Modulation Schemes
16- to 256-QAM 16- to 4096-QAM
Guard Interval Not Applicable 1/64 or 1/128
Inverse Fast Fourier transform (IFFT) size
Not Applicable 4k[6]
Interleaving Bit-Interleaving Bit- Time- and Frequency-Interleaving
Pilots Not Applicable Scattered and Continual Pilots
DVB-T
• DVB-T offers three different modulation schemes (QPSK, 16QAM, 64QAM)
• A terrestrial (over-the-air) transmission carries 19.39 megabits of data per second
DVB-H
• Sub-standard of DVB-T, introduced for Hand Held devices like Mobile
• Was not successful.
• Transmission made through DVB is not only Video, but Data as well
• It contains:
• Network Information Table(NIT)
• Transport Stream ID (TS-ID)
• Service Description Table (SDT)
The IRD is the interface between a receiving satellite dish and a broadcasting facility video/audio infrastructure.
Integrated receiver decoder
INPUT RF OUTPUT ASI/AV
CAPABLE TO DESECRAMBLE PAID CHANNELS
IRD
Advantages:
• DVB
• - High bandwidth outbound or broadcast
• - Designed and built for Video Broadcast
• - Lower Cost of Remote Terminals
Disadvantages:
• - Generally Power-Limited satellite requirement
• - Very inefficient when use of transponder capacity
• - Not designed for TCP/IP traffic. IP is encapsulated within MPEG
• - Very high Hub equipment cost
1. Used for re-multiplexing of digital channels 2. 8 ASI Inputs, 2 ASI Outputs 3. Web Based Management/Server ROSA
Management 4. Input stream has multiple channels and we select
only which we need 5. We are using 4 Muxes 9600
Multiplexer 9600(SA)
1. Output of Mux 9600 is given to QAM Modulator2. Used for QAM (Quadrature Amplitude Modulation) at Digital Frequencies3. We use 64 QAM (other types are 32, 128, 256)4. ASI Input, RF Output5. Limitation of Maximum 38.2 Mbps per QAM 6. One QAM, One Digital Frequency
QAM Modulator (SA)
1. Used to open complete stream of scrambled
channels2. ASI In, ASI Out3. Web Based Management4. Work with Sharing Card
Descrambler (SA)
1. Enhanced Multimedia Router (EMR) by Sumavision
2.Major Purpose is to add AV channels in Digital
3.6 cards per chassis
4.5 Analog MPEG2 AV Input cards, 2 AV inputs per card
5.1 Output Card, 2 ASI In, 2 ASI Out
6.Total Inputs: 10 AV and 2 ASI
7.Total Outputs: 2 ASI
8.Management through Application ‘Netmanager’
9.Other cards are ASI Combiners, HDMI Input, Satellite Tuner, IP Output
EMR
1. Multiplexer for Digital and IP TV
2. 16 ASI inputs
3. IP output
4.Supports Multicast, Unicast and all types of QAM streams
5. Management through application ‘Cherrypicker’
6.Number of RF Muxes depends upon APEX QAM cards
Mix DM6400
1. QAM Modulator for Mux DM 6400
2. Coverts IP to RF
3. Total 3 Cards
4. Each card has 2 ports
5. Each port support 2 digital frequencies
6. 4 frequencies per card
7. 12 frequencies for APEX
Apex 1000
MUX
QAMCombinerOptical TX
EMR
A/V Free And Paid Digital Channel Block ROSA SYSTEM
Receiver/Decoder
DM 6400
Apex CombinerOptical TX
A/V Free And Paid Digital Channel Block MOTOROLA SYSTEM
EMR Receiver/Decoder
Ethernet Switch
1. Used to share one Descrambling in multiple receivers and descramblers
2.Card is inserted in main device and sharing cards are connected with this main device
3.Other receivers/descramblers work with sharing cards
Sharing Devices
1. VOLT (Video Optical Line Terminal) by Scientific Atlanta2. Used in distribution of Fiber Network3. Chassis in Data Center converts RF network to Fiber (Optical
Network)4. Chassis in POPs used for distribution and amplification5. One chassis has 15 Slots6. First four slots are reserved for Power and last 15th slot is for
management card7. Rest of the slots are for Amplifiers
Prism Chassis