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Alitronika has all the answers |
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Q33- What are the differences between the Japanese and Brazilian ISDB-T standards?
A- The transmission system in Brazil is the same as Japanese system except
for transmission spectrum mask and receiver IF frequency.
Brazil adopts MPEG-4 as video coding system and GINGA, Brazilian data casting system, which has been developed by Brazil.
For handheld service named "One-seg", the field frequency is different. In addition, the SBR (Spectral Band Replication) is available for audio coding in Brazil.
Q32- What is the bit rate of ISDB-T for fixed and mobile/ handheld reception ?
A- In case of ISDB-T system, it is slightly complicate to calculate bit rate because hierarchical transmission is possible.
An example of bit rate for fixed reception and mobile/ handheld reception
HD fixed reception + One-seg service in one 6MHz bandwidth
(a) HD service for fixe reception: 12segment, 64QAM, r=3/4, bitrate=16.85 Mbps
(b) One-seg service for portable reception: 1 segment, QPSK, r=2/3, bitrate=416 kbps
Q31- What is the time interleaving and how does it work for portability and mobile?
A- In general digital communication system
adopts error correction system with interleave technology. The error
correction system shows best performance in case of random error
pattern. Time interleave technology is adopted to randomize many degradation
factors, such as man-made noise, multi-path fading, interference to get
best error correction process. In this respect, time interleave technology is very effective to improve
receiving performance and it much contribute to the realization for
mobile/ portable reception and indoor fixed reception.
Q30- Is SFN, used by ISDB-T, possible for ATSC and DVB-T?
A- Because ATSC adopts single carrier system, it is quite difficult for ATSC to work in SFN. On the other hand, ISDB-T and DVB-T adopt multi-carrier system, named
OFDM, therefore, basically both systems can work in SFN. DVB-T does not adopt a time interleave technology, therefore, mobile/indoor reception performance of DVB-T is inferior to that of ISDB-T in
SFN, hence the introduction of DVB-T2 which does support interleaving.
Q29- Do all the segments have the same number of carriers? ( Including the
"One-seg" segment )
A- Yes, each segment composing ISDB-T signal has same
band-width/number of carrier/carrier spacing.
The number of carrier/channel spacing is different, depending on "mode", but these parameters of each segment are same.
Q28- How is multi-lingual services implemented in ISDB-T system?
A- Japan adopts MPEG2-AAC and Brazil adopts MPEG4-AAC for audio coding system respectively. These coding systems support monaural,
stereo, multi-channel stereo, dual and multi-audio service.
Q27- What kinds of video/audio format are used?
A- Both Japan and Brazil digital broadcasting system support both
HD and Multi-SD service. If ISDB-T based on Japan/Brazil
system is adopted, users can select any of HD,
Multi-SD or compound service of HD/SD. In case of DVB-T system, many countries adopt Multi-SD service only.
Q26- How many programs can be broadcast at the same time?
A- ISDB-T adopts MPEG-2 systems for service
multiplexing system. The number of service in a channel should be
decided as a operational guideline considering a trade off of service
request and service quality. In Japan, broadcasting companies usually provide One HD program and
sometimes up to 3 SD programs.
Q25- How the AT2780PCI be up-graded to support DVB-T2 modulation & what are the differences between DVB-T2 & DVB-T?
A- Please refer to " How does the support for DVB-T2 modulation by AT2780PCI all work? "
document.
The goal of DVB-T2 is to improve on a ten-year old standard
and put terrestrial broadcasters in the 21st
century. It is the second generation digital
terrestrial transmission (DTT) standard,
succeeding DVB-T, which was developed in
1995 and is used by most of the DTT
implementations around the world. DVB-T2
promises at least a 30% improvement in capacity. Simulations have shown that up to 60%
capacity improvement is attainable, although
exact performance gains depend on the
parameters that are chosen. Significant
innovations of the new specification
compared to DVB-T include new forward
error protection, high-order modulation modes, variable modulation and coding of
services and increase in the number of
OFDM carriers.
Principally, the increase in data
throughput is achieved by employing
enhanced forward error correction (FEC)
schemes, such as LDPC schemes, as
opposed to just BCH convolution used in
DVB-T. It is essentially the same LDPC that
DVB-S2 introduced to improve DVB-S. This
suggests around a 2dB improvement, which
can be converted to capacity either through
using less error correction or moving to a
higher order constellation, such as
256QAM (DVB-T allows up to a 64-QAM
constellation per carrier).
Significantly, there is a 32k carrier mode,
in addition to 2k and 8k for DVB-T. The benefits this option brings is the
ability to use single frequency networks
(SFN) and increased robustness to impulse
interference. This makes the 32k mode
extremely important as part of the DVB-T2
spec. TFS,Time Frequency Slicing, is a technique that allows services to
be spread over more than one multiplex,
maximising the benefits of statistically
multiplexing more services, a harder issue
when moving from SD to HD. As with MIMO, the concept of TFS is extremely
compelling, but it looks like it has not made
its ways into the original specification given
its broader complexity from a chipset point
of view. The compromise decision in the
DVB-T2 is to have the TFS as an
optional part of the spec.
|
DVB-T |
DVB-T2 |
Error
Correction |
BCH |
LDPC |
Modulation |
QPSK,
16QAM, 64QAM |
Addition of
256QAM |
FET |
2k, 8k |
Addition of
32k |
Bandwidth |
5,6,7 &
8MHz |
5,6,7 &
8MHz |
TS rate (
RF ) |
24 to 32
Mbps |
44Mbps + |
Physical
layer |
Mpeg-2 |
Mpeg2 &
IP Basband |
Codecs |
Mpeg2,
Mpeg4, AVC, VC1 |
Mpeg2,
Mpeg4, AVC, VC1 |
Q24- How can I up-grade
AT2780PCI /USB to support ATSC-8VSB & the AT2900PCI/USB to
support DSNG ?
A- It has always been Alitronika's policy to offer the best value for our customers. We are pleased to announce
the addition of full ATSC-8VSB modulation support ( compliant with
ATSC A/53 8-VSB ) to our AT2780PCI /USB, Muti-Standard
DVB-T/H/C modulator devices. The DVB-S2/S modulator devices, AT2900PCI/USB,
now have support for DSNG. All these function are available to all
users at NO EXTRA COST. In order to use this new functions
just download and install the latest version of our application
software, DVSStation3 from our website. The rest is done
automatically for you.Q23- What is DSNG ?
A- Satellite news
gathering (SNG) is the use of mobile communications equipment for
the purpose of worldwide newscasting. Mobile units are usually vans
equipped with advanced, two-way audio and video transmitters and
receivers, using dish antennas that can be aimed geo-stationary satellites.
The earliest SNG equipment used analog modulation similar to conventional television and radio.
During the 1990s, digital modulation supplanted analog modulation, giving rise to the newer technology of
digital satellite news gathering (DSNG). A modern DSNG van is a sophisticated affair, capable of deployment
practically anywhere in the world. Signals are beamed between a
geo-stationary satellite and the van, and between the satellite and a
control room run by a broadcast station or network. In the most
advanced systems, Internet Protocol, IP, is used.
Broadcast engineers are currently working on designs remotely
controlled, robotic
DSNG vehicles that can be tele-operated in hostile environments such as battle zones, deep space missions, and
under sea explorations
without endangering the lives of human operators.
Q22- When using DVB-T/H/C
modulator devices the application software sometimes gives high
bitrate error message. How do I set the correct parameters for bit
error free modulation?
A-
These parameters are specified in the DVB-T, DVB-C standards. Please refer
relevant DVB documents for full information and explanation, click on
the link blow to see a summery of these settings for modulation parameters.
Click here to see Bitrate Tables
Q21- We have bought a PCI based DVB-T from another supplier, the application
places a significant load on the CPU. For OFDM/8MHz/8K/64QAM/(7/8)/Gaurd(1/4) it has the CPU occupancy of more than
33% on a D840EE computer with 1GB RAM. Considering the price of the modulator and the application software,
this is rather a large load. What is the CPU occupancy of AT2800USB and AT2800PCI DVB-T/H modulator devices?
A- Using a similar PC as you are using, we measured the CPU load of Alitronika's DVB-T modulators as follows:
- When the TS is from an external source, via the DVB-ASI or DVB-SPI input => CPU occupancy = 0%
- When the TS is played from the harddisk on the same PC => CPU occupancy =
2% or less.
Click here to see CPU Usage Report
Q20- We would like to use the 70MHz IF output of the
AT2800USB/PCI with our up-converter, is it possible to see some test
result for the modulator devices?
A- Yes
we have an extensive test report.Click here to see
the test report
Q19- We need to buy DVB-T/H
& DVB-C modulators, when is the
AT2800/AT2700 are ready for delivery ? A- The
AT2800USB, AT2800PCI, AT2700USB, AT2700PCI
and the AT2780USB, AT2780PCI are now in full production.
Q18- Is your application
software FREE or do I have to pay for it ? A-
Our application software, DVSStation2, is FREE
with all our products and you can always download the latest version
from our website. In fact you can download it even if you do not
have any of our products in which case it enters into the demo mode
and you can try it out. You can transmit and receive any Transport
Stream
EXpress
to/from any device.
Q17- Do you have TS
Analyser Software ? A- The
latest version of our application software, DVSStation2, has an
integrated Real Time TS Analyser function.
And it is all FREE with every Alitronika's product.
Why pay for the same functions ( OK, with addition of some fancy GUI
! ) when you can get it for free from us.
Q16- Does DVSStation2
support all your products or do we have to buy different
software for each product ? A-
The DVSStation2 is an integrated Transport Stream Player, Recorder,
Monitor and Real Time Quick TS Analyser. It Supports all our
products. You do not need anything else. It has all the functions
for capturing full transport Streams on your harddisk and playing
any TS from your harddisk. It also allows you to select the
Tuner and LNB settings for DVB-S, DVB-T and DVB-C. In addition it
allows you to analyse the TS files during play or record.
Q15- Have you got a
Visual mpeg analyser or could you recommend a suitable one ? A-
There are a few Visual mpeg analysers around, this is one reason why
we
do not have one of our own. You could try the VISUALmpeg. It is not hardware dependent, so it works
with devices from all
vendors, and it is probably better and is more cost effective than
some others which only work with the hardware from the same vendor,
so you end up buying their hardware as well. This is how they
describe it on their website : " VISUALmpeg
is a software tool the user can analyze MPEG Video streams with. It
is a program for windows and needs no special hardware. The
MPEG-Streams have to be on the harddisk. Live-input streams cannot
be analyzed. The user can choose the different information he wants
to get from the MPEG-Video stream. This homepage shows a few
pictures, analyzed by the program."
To get more information just click
on the logo below, or go to:www.mpeg-analzer.com
Q14- We have a
supplier who charges us too much and has not got most of the
products we need. We would like to change our current supplier
and we see Alitronika has all the products we need. How can we
become your distributor ? A-
You are very much welcome to join us as so many others have already
done. We offer you the best terms and conditions. Our prices are
already much lower and with free application software included with
every products, you have no problems finding buyers. Extra discounts
are considered for support and promotion of our products. Above all
we reward your contribution towards making sure our customers are
fully supported.
Q13- Is there any Decoder function
on your DVB-T/S/C devices? A- No,
there are no decoders on board these devices.
Q12- Can I store Full
Transport Stream, including the Null packets, on my Harddisk
using Alitronika's DVB-T, DVB-S or DVB-C devices? A- Yes.
Q11- Can the recorded
Transport Streams be played by other supplier's players like
Tek, Actern, R&S ..... ? A-
Yes, the recorded file can be played by other TS players.
Q10- Can your
transport stream player playback TS files recorded by
other supplier's devices? What if the TS has errors or does not
start with a 47H ? A-
Yes, the DVSStation can playback all recorded TS
files, even if there are corrupted packets or they do not start
with a 47H.

Q9- In the
datasheets the clock accuracy of 25ppm is stated. Is there an option
for a more accurate clock ? A-
Yes you can have a clock as accurate as 1ppm if you
like.
Q8- We buy our
boards from another supplier, but it has not got all the function we
need, the firmware does not allow customisation. Can your boards be
customised ? A- Yes,
the firmware on our products are not programmed at factory. They are
loaded every time you start your PC. So we can make different
firmware with the functionality you need for you.
Q7- I have some old
equipments which have ECL input & output rather than LVDS. Is
there an option for ECL input and output ? A- Yes,
you could select the LVDS or ECL options for the parallel
inputs & outputs.
Q6- Has your system got
the capability of adding Time Stamp to each MPEGII packets ?
A- Yes, you can
select " Time Stamping" as an option while recording a
Transport Stream in which case the hardware inserts four bytes of
"time stamp" at the start of each packets. These time
stamp bytes are taken when the byte 11 of the TS arrives at the
receiver input.
Q5- We are looking for a
DVB card to use with Microsoft DirectShow API, does any of you cards
support this API ? A- Yes,
we have a BDA driver which works with DirectShow.
Q4- We are using the
AT600USB, DVB-S, device to capture the received transport
streams from the Ku band signal, does this device also
work with C band? A- The
support for C band depends on the dish, the LNB, the
transmission and so on. If the incoming signal ( 4-6 GHz for C band
) is converted to the 950-2150 MHz range of AT600USB and it is DVB
compatible ( and not DSS ) then there is no reason why it does not
work with AT600USB device.

Q3- We are using
AT20USB device together with our MPEG Encoder to provide a function
for recording TS files into the harddisk . Everything
works well. But is there a way to start and stop the recording
without using the start & stop buttons on DVSStaion? A- Yes,
the DVSStaion automatically stops recording when there is no
incoming data ( Transport Streams ) and starts again when there
is data. So if your encoder is not sending any Transport stream out
the recording stops. Please remember for the recording option select
"Mbytes" rather than the recording time.
Q2- Do your DVB-T devices have capability
of receiving the 7MHz bandwidth Digital RF signal in Australia ?
A- Yes,
AT800PCI, AT800USB and AT80USB all support 7MHz and 8MHz
bandwidth.
Q1- Could
you outline some of the functions of AT400PCI device ? - Record Transport streams from any DVB-ASI or
DVB-SPI on your harddisk. - Play any transport stream files from your
harddisk via DVB-ASI / DVB-SPI. - Record SMPTE ( SDI ) or Play SMPTE
( SDI ) signals. - Using Loopthrough & passthrough functions, use
it as 1 to 3 signal router. - Convert Serial ( ASI ) into Parallel (
SPI ) - Convert Parallel ( SPI ) into ( ASI ) - Convert LVDS/ECL level
signals into LVTTL/LVCMOS levels -Convert LVTTL/LVCMOS
level signals into LVDS/ECL levels

 |
Definition
of Terms from Wikipedia, the free encyclopaedia. |
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- The
following articles are licensed under the
GNU
Free Documentation License.
DVB short
for Digital Video Broadcasting, is a suite of
internationally accepted, open
standards for digital
television maintained by the DVB Project, an
industry consortium with more than 270 members, and published
by a Joint Technical Committee (JTC) of European
Telecommunications Standards Institute (ETSI), European
Committee for Electrotechnical Standardization (CENELEC)
and European
Broadcasting Union (EBU). The standards can be obtained
for free at the ETSI
website after registration.
How the several DVB sub-standards
interact is described in the DVB Cookbook (DVB-Cook).
DVB-S
is the Digital
Video Broadcasting standard for satellite
television. It is used through all of Europe
and most of the rest of the world. This is even true in North
America, where it pre-dates the use of ATSC
by several years. DVB-S is used in both SCPC
and MCPC
modes for broadcast
network feeds,
as well as for direct
broadcast satellite services like Astra
in Europe, Dish
Network in the U.S.,
and Bell
ExpressVu in Canada.
While the transport
stream is essentially the same as other forms of DVB, it
uses QPSK
modulation
instead.
DVB-S2
is a newer specification of the DVB-S standard, ratified by ETSI
in March
2005. The main use for this is HDTV,
while the original standard was mainly for SDTV.
DVB-S2 is tightly tied with the introduction of HDTV and H.264
(MPEG-4)
video
codecs.
The authors claim that DVB-S2
performance gain over DVB-S is around 30%, in addition to
improvements in the video
compression.
DVB-S2 is being introduced now in
Europe. Since November
2005, two transponders on Astra at 19.2°E send in DVB-S2.
DirecTV
is also introducing it in the U.S., although its original
system was Digital
Satellite System (DSS), which uses MPEG-2
but with a different transport stream.
DVB-C stands for Digital Video Broadcasting - Cable
and it is the DVB
European consortium standard for the broadcast transmission of
digital
television over cable.
This system transmits an MPEG-2
family digital audio/video stream, using a QAM
modulation with channel
coding.
DVB-T stands for Digital Video Broadcasting -
Terrestrial and it is the DVB
European consortium standard for the broadcast transmission of
digital
terrestrial television. This system transmits a compressed
digital audio/video stream, using OFDM
modulation with concatenated channel
coding (i.e. COFDM). The adopted source coding methods are
MPEG-2
and, more recently, H.264.
DVB-T2
is an abbreviation for Digital Video Broadcasting – Second Generation
Terrestrial; it is the extension of the television standard DVB-T, issued
by the consortium DVB, devised for the broadcast transmission of Digital Terrestrial
TV. This system transmits compressed digital audio, video, and other data in
"physical layer pipes" (PLPs), using OFDM modulation with
concatenated channel coding and interleaving. It is currently broadcasting in
parts of the UK under the brand name Freeview HD.
The following characteristics have been devised for the T2 standard:
-
COFDM modulation with QPSK, 16-QAM, 64-QAM, or 256-QAM (but not 128-QAM)
constellations.
-
OFDM modes are 1k, 2k, 4k, 8k, 16k, and 32k. The symbol length for 32k mode is
about 4 ms.
-
Guard intervals are 1/128, 1/32, 1/16, 19/256, 1/8, 19/128, and 1/4. (For 32k
mode, the maximum is 1/8.)
-
FEC is LDPC and BCH (as in DVB-S2), with rates 1/2, 3/5, 2/3, 3/4, 4/5, and
5/6.
-
There are fewer pilots, in 8 different pilot-patterns, and equalization can be
based also on the RAI CD3 system.
-
In the 32k mode, a larger part of the standard 8 MHz channel can be used,
adding about 2% extra capacity.
-
DVB-T2 is specified for 1.7, 5, 6, 7, 8, and 10 MHz channel bandwidth.
-
MISO (Multiple-Input Single-Output) may be used (Siavash
Alamouti scheme), but MIMO will not be used. Diversity receivers can be
used (as they are with DVB-T).
-
Bundling of more channels into a SuperMUX (called TFS) is not in the standard,
but may be added later.
Comparison of available modes in DVB-T and DVB-T2:
|
DVB-T
|
DVB-T2
|
FEC
|
Convolutional Coding + Reed Solomon 1/2, 2/3, 3/4, 5/6, 7/8
|
LDPC + BCH 1/2, 3/5, 2/3, 3/4, 4/5, 5/6
|
Modes
|
QPSK, 16QAM, 64QAM
|
QPSK, 16QAM, 64QAM, 256QAM
|
Guard Interval
|
1/4, 1/8, 1/16, 1/32
|
1/4, 19/256, 1/8, 19/128, 1/16, 1/32, 1/128
|
FFT size
|
2k, 8k
|
1k, 2k, 4k, 8k,
16k, 32k |
Scattered Pilots
|
8% of total
|
1%, 2%, 4%,
8% of total |
Continual Pilots
|
2.6% of total
|
0.35%
of total
|
For instance, a UK MFN DVB-T profile (64-QAM, 2k mode, coding rate 2/3, guard
interval 1/32) and a DVB-T2 equivalent (256-QAM, 32k, coding rate 3/5, guard
interval 1/128) allows for an increase in bit rate from 24.13 Mbit/s to 35.4
Mbit/s (+46.5%). Another example, for an Italian SFN DVB-T profile (64-QAM, 8k,
coding rate 2/3, guard interval 1/4) and a DVB-T2 equivalent (256-QAM, 32k,
coding rate 3/5, guard interval 1/16), achieves an increase in bit rate from
19.91 Mbit/s to 33.3 Mbit/s (+67%).
Status of the DVB-T2 specification
The DVB-T2
draft standard ratified by the DVB Steering Board on June 26,
2008, and
published on the DVB homepage as DVB-T2 standard BlueBook,
has been handed over to the European Telecommunications
Standards Institute by DVB.ORG on June 20, 2008. The ETSI
process resulted in the DVB-T2 standard being adopted on
September 9th, 2009.. The ETSI process had several phases, but
the only changes were text clarifications.DVB-T2 modulators
are on the market and receiver chips are under development.
Prototype receivers were shown in September IBC 2008 and more
recent version at the IBC 2009 in Amsterdam. A number of other
manufacturers are demonstrating DVB-T2 at IBC 2009 including
Albis Technologies, Arqiva, Enensys, Harris, Pace, Rohde &
Schwarz, Tandberg, and TeamCast according to
BroadbandTVNews.com. It reports that other manufacturers
planning DVB-T2 equipment launches include Alitronika,
CellMetric, Cisco, Digital TV Labs, Humax, NXP Semiconductors,
Panasonic, ProTelevision Technologies, Screen Service, SIDSA,
Sony, ST Microelectronics and T-VIPS.
Since the DVB-T2 physical layer specification is complete, and there will be no
further technical enhancements, receiver VLSI chip design has been started with
confidence in stability of specification. A draft PSI/SI (program and system
information) specification document has been agreed with the DVB-TM-GBS group.
DVB-H stands for Digital
Video Broadcasting - Handheld.
DVB-H is a technical specification for bringing broadcast
services to handheld receivers and was formally adopted as ETSI
standard EN 302 304 in November 2004. The DVB-H specification
(EN 302 304) can be downloaded from the DVB-H Online website.
The major competitor of this technology is DMB.
MPEG-2 is the designation for a group of coding and compression
standards for Audio and Video (AV), agreed upon by MPEG
(Moving Picture Experts Group), and published as the ISO/IEC
13818 international standard. MPEG-2 is typically used to
encode audio and video for broadcast signals, including direct
broadcast satellite and Cable
TV. MPEG-2, with some modifications, is also the coding format
used by standard commercial DVD
movies. Using MPEG2 requires paying licensing fees to the
patent holders via the MPEG Licensing Association.
MPEG-2 includes a Systems part (part 1) that defines two
distinct (but related) container formats. One is Transport
Stream, which is designed to carry digital video and audio
over somewhat-unreliable media. MPEG-2 Transport Stream is
commonly used in broadcast applications, such as ATSC
and DVB.
MPEG-2 Systems also defines Program Stream, a container format
that is designed for reasonably reliable media such as disks.
MPEG-2 Program Stream is used in the DVD
and SVCD
standards.
The Video part (part 2) of MPEG-2 is similar to MPEG-1,
but also provides support for interlaced
video (the format used by analog broadcast TV systems). MPEG-2
video is not optimized for low bit-rates (less than 1 Mbit/s),
but outperforms MPEG-1 at 3 Mbit/s and above. All
standards-conforming MPEG-2 Video decoders are fully capable
of playing back MPEG-1 Video streams.
With some enhancements, MPEG-2 Video and Systems are also
used in most HDTV
transmission systems.
The MPEG-2 Audio part (defined in Part 3 of the standard),
enhances MPEG-1's audio by allowing the coding of audio
programs with more than two channels. Part 3 of the standard
allows this to be done in a backwards compatible way, allowing
MPEG-1 audio decoders to decode the two main stereo components
of the presentation.
Part 7 of the MPEG-2 standard specifies a rather different,
non-backwards-compatible audio format. Part 7 is referred to
as MPEG-2 AAC.
While AAC is more efficient than the previous MPEG audio
standards, it is much more complex to implement, and somewhat
more powerful hardware is needed for encoding and decoding.
SMPTE- The Society
of Motion Picture and Television Engineers (pronounced "simptee" or sometimes "sumptee")
is an international professional association, based in
the United
States of America, of engineers working in the motion
imaging industries. An internationally-recognized standards
developing organization, SMPTE has over 400 standards,
Recommended Practices and Engineering Guidelines for
television, motion pictures, digital cinema, audio and medical
imaging. In addition to development and publication of
standards documents, SMPTE publishes a journal, provides
assistance to members with employment, and performs other
industry-related functions.SMPTE standards documents are copyrighted and may be
purchased from the SMPTE website, or other distributors of
technical standards. Standard documents may be purchased by
the general public. Significant standards promulgated by SMPTE
include:
- All film and television transmission formats and media,
including digital.
- Physical interfaces for transmission of television
signals and related data (such as SMPTE
time code)
- The SMPTE
color bar test
pattern and other diagnostic tools
- The Material eXchange Format, or MXF
SDI- Serial Digital Interface,
standardized in ITU-R
BT.656 and SMPTE-259M,
is a digitized video
interface used for broadcast
grade video. A related standard, known as High Definition
Serial Digital Interface (HD-SDI) is standardized in
SMPTE-292M; this provides a nominal date rate of 1.485 Gbit/s.
An emerging interface, commonly known in the industry as dual
link and consisting essentially of a pair of SMPTE 292M
links, is standardized as SMPTE 372M; this provides a nominal
2.97 3 Gbit/s nominal interface used in applications (such as digital
cinema) which require greater fidelity and resolution than
standard HDTV can provide. A more recent interface, consisting
of a single 2.97 Gbit/s serial link, is standardized by SMPTE
424M,
These standards are used for transmission of uncompressed,
unencrypted digital television signals (optionally including
audio) within television facilities; they can also be used for
packetized data. They are designed for operation over short
distances; due to their high bitrates they are inappropriate
for long-distance transmission. SDI and HD-SDI are currently
only available in professional video equipment; various
licensing agreements, restricting the use of unencrypted
digital interfaces to professional equipment, prohibit their
use in consumer equipment. (There are various mod
kits for existing DVD
players and other devices, which allow a user to add a
serial digital interface to these devices).
PCI-
Peripheral Component Interconnect standard (in
practice almost always shortened to PCI) specifies a computer
bus for attaching peripheral
devices to a computer
motherboard.
These devices can take any one of the following forms:
The PCI bus is common in modern PCs,
where it has displaced ISA
and VESA
Local Bus as the standard expansion bus, but it also
appears in many other computer types. The bus will eventually
be succeeded by PCI
Express and other technologies, which have already started
to appear in new computers.
The PCI specification covers the physical size of the bus
(including wire spacing), electrical characteristics, bus
timing, and protocols. The specification can be purchased from
the PCI
Special Interest Group (PCISIG).
USB-
Universal Serial Bus is a serial
bus
standard to interface
devices. It was designed for computers
such as PCs
and the Apple
Macintosh,
but its popularity has prompted it to also become commonplace
on video
game consoles, PDAs,
cellphones;
and even devices such as televisions
and home stereo equipment (e.g., mp3
players), and portable
memory devices.
Transport stream (TS) is a format specified in MPEG-2
Part 1, Systems (ISO/IEC standard 13818-1). Its design goal is
to allow multiplexing of digital video and audio and to
synchronize the output. Transport stream offers features for
error correction for transportation over unreliable media, and
is used in broadcast applications such as DVB
and ATSC.
BDA- Broadcast Driver Architecture is a
Microsoft standard for digital
video capture on their Windows operating systems. It
encompasses the ATSC
and DVB
standards and gives developers a standardised method of
accessing the TV cards.
Applications using BDA drivers: Windows
XP Media Center Edition, MediaPortal,
GB-PVR
LVDS - Low voltage differential signaling, is an
electrical signaling system that can run at very high speeds
over cheap, twisted-pair
copper cables. It was introduced in 1994,
and has since become very popular. LVDS is a differential signaling system, which means that
it transmits two different voltages which are compared at the
receiver.
LVDS uses the difference in voltage between two wires to
signal information. The transmitter injects a small current,
nominally 3.5 milliamperes,
into one wire or the other, depending on the logic level to be
sent. The current passes through a resistor of about 100 to
120 ohms (matched to the characteristic
impedance of the cable) at the receiving end, then returns
in the opposite direction along the other wire. From Ohm's
law, the voltage difference across the resistor is
therefore about 350 millivolts.
The receiver senses the polarity of this voltage to determine
the logic level. (This is a type of current
loop signaling).
The small amplitude
of the signal and the tight electric- and magnetic-field
coupling between the two wires reduces the amount of radiated
electromagnetic noise.
The low common-mode voltage (the average of the voltages on
the two wires) of about 1.25 V allows LVDS to be used with a
wide range of integrated circuits with power supply voltages
down to 2.5 V or lower. The low differential voltage, about
350 mV as stated above, causes LVDS to consume very little
power compared to other systems. For example, the static power
dissipation in the LVDS load resistor is 1.2 mW, compared to
the 90 mW dissipated by the load resistor for an RS-422
signal. This power efficiency is maintained at high
frequencies because of the low voltage swing.
Bitrate- In telecommunications
and computing,
bitrate (sometimes written bit rate, or as a variable
Rbit) is the number of bits
that are conveyed or processed per unit of time. In digital multimedia,
bitrate is the number of bits used per unit of time to
represent a continuous medium such as audio
or video.
It is quantified using the bit per second (bit/s)
unit or some derivative such as Mbit/s.
While often referred to as "speed", bitrate does
not measure distance/time but quantity/time, and
thus should be distinguished from the "propagation
speed" (which depends on the transmission medium and
has the usual physical meaning).
Symbol rate- In
digital
communications, the symbol rate is the bit
rate divided by the number of bits transmitted in each symbol.
Symbol rate is measured in symbols-per-second, hertz
(Hz), or baud
(Bd).
The term baud
rate is synonymous with symbol rate, but is less
frequently used today as it has in the past been commonly
misused to mean bit
rate or data
rate.
COFDM- Orthogonal
frequency-division multiplexing, also
sometimes called discrete multitone modulation
(DMT), is a complex modulation
technique for transmission based upon the idea of frequency-division
multiplexing (FDM) where each frequency channel is
modulated with a simpler modulation.
In OFDM the frequencies and modulation of FDM are arranged to
be orthogonal
with each other which almost eliminates the interference
between channels. Although the principles and some of the
benefits have been known for 40 years, it is made popular
today by the lower cost and availability of digital
signal processing components.
The main idea behind OFDM is that since low-rate
modulations (i.e modulations with relatively long symbols
compared to the channel time characteristics) are less
sensitive to multipath, it should be better to send a number
of low rate streams in parallel than sending one high rate
waveform. This is exactly what OFDM is doing. It divides the
frequency spectrum in subbands small enough so that the
channel effects are constant (flat) over a given subband. Then
a "classical" IQ modulation (BPSK, QPSK, M-QAM, etc)
is sent over the subband. If designed correctly, all the fast
changing effects of the channel (multipath) disappear as they
are now occurring during the transmission of a single symbol
and are thus treated as flat fading at the received.
Classical signal processing such as channel coding, power
allocation, adaptive modulation and coding can be applied for
a given subband or over the subbands. Multiuser allocation is
also possible, either using time, coding or frequency
separation of the users.
QAM- Quadrature amplitude modulation is a modulation
scheme which conveys data
by changing (modulating) the amplitude
of two carrier
waves. These two waves, usually sinusoids,
are out
of phase with each other by 90°
and are thus called quadrature
carriers — hence the name of the scheme.
As with all modulation
schemes, QAM conveys data
by changing some aspect of a carrier signal, or the carrier
wave, (usually a sinusoid)
in response to a data signal. In the case of QAM, the
amplitude of two quadrature waves is changed (modulated
or keyed) to represent the data signal.
Phase
modulation (analogue PM) and phase-shift
keying (digital PSK) can be regarded as a special case of
QAM, where the amplitude of the modulating signal is constant,
with only the phase varying. This can also be extended to frequency
modulation (FM) and frequency-shift
keying (FSK), as this can be regarded as a special case of
phase modulation.
Although analogue QAM is possible, this article focuses on
digital QAM. Analogue QAM is used in NTSC
and PAL
television systems, where the I- and Q-signals carry the
components of chroma (colour) information. "Compatible
QAM" or C-QUAM
is used in AM
stereo radio
to carry the stereo
difference information.
As for many digital modulation schemes, the constellation
diagram is a useful representation and is relied upon in
this article.
In QAM, the constellation points are usually arranged in a
square grid with equal vertical and horizontal spacing,
although other configurations are possible (see e.g. Cross-QAM).
Since in digital telecommunications
the data is usually binary,
the number of points in the grid is usually a power of 2
(2,4,8...). Since QAM is usually square, some of these are
rare — the most common forms are 16-QAM, 64-QAM, 128-QAM and
256-QAM. By moving to a higher-order constellation, it is
possible to transmit more bits
per symbol.
However, if the mean energy of the constellation is to remain
the same (by way of making a fair comparison), the points must
be closer together and are thus more susceptible to noise
and other corruption; this results in a higher bit
error rate and so higher-order QAM can deliver more data
less reliably than lower-order QAM.
If data-rates beyond those offered by 8-PSK
are required, it is more usual to move to QAM since it
achieves a greater distance between adjacent points in the I-Q
plane by distributing the points more evenly. The complicating
factor is that the points are no longer all the same amplitude
and so the demodulator
must now correctly detect both phase
and amplitude,
rather than just phase.
64-QAM and 256-QAM are often used in digital
cable television and cable
modem applications. In the US,
64-QAM and 256-QAM are the mandated modulation schemes for digital
cable, as standardised by the SCTE
in the standard ANSI/SCTE
07 2000. Note that many marketing people will refer to
these as QAM-64 and QAM-256. In the UK,
16-QAM and 64-QAM are currently used for digital
terrestrial television (Freeview
and Top
Up TV).
QPSK- Sometimes known as
quaternary or quadriphase PSK or 4-PSK, QPSK uses four points
on the constellation diagram, equispaced around a circle. With
four phases, QPSK can encode two bits per symbol, shown in the
diagram with Gray
coding to minimize the BER — twice the rate of BPSK.
Analysis shows that this may be used either to double the data
rate compared to a BPSK system while maintaining the bandwidth
of the signal or to maintain the data-rate of BPSK but halve
the bandwidth needed.
Although QPSK can be viewed as a quaternary modulation, it
is easier to see it as two independently modulated quadrature
carriers. With this interpretation, the even (or odd) bits are
used to modulate the in-phase component of the carrier, while
the odd (or even) bits are used to modulate the quadrature-phase
component of the carrier. BPSK is used on both carriers and
they can be independently demodulated.
PSK- Phase-shift keying is a digital
modulation
scheme that conveys data
by changing, or modulating, the phase
of a reference signal
(the carrier
wave).
Any digital modulation scheme uses a finite
number of distinct signals to represent digital data. In the
case of PSK, a finite number of phases are used. Each of these
phases is assigned a unique pattern of binary
bits.
Usually, each phase encodes an equal number of bits. Each
pattern of bits forms the symbol
that is represented by the particular phase. The demodulator,
which is designed specifically for the symbol-set used by the
modulator, determines the phase of the received signal and
maps it back to the symbol it represents, thus recovering the
original data. This requires the receiver to be able to
compare the phase of the received signal to a reference signal
— such a system is termed coherent.
Alternatively, instead of using the bit patterns to set
the phase of the wave, it can instead be used to change
it by a specified amount. The demodulator then determines the changes
in the phase of the received signal rather than the phase
itself. Since this scheme depends on the difference between
successive phases, it is termed differential phase-shift
keying (DPSK). DPSK can be significantly simpler to
implement than ordinary PSK since there is no need for the
demodulator to have a copy of the reference signal to
determine the exact phase of the received signal (it is a
non-coherent scheme). In exchange, it produces more erroneous
demodulations. The exact requirements of the particular
scenario under consideration determine which scheme is used.
ATSC-M/H
(Advanced Television Systems Committee - Mobile/Handheld)
is a standard in the USA for mobile
digital TV, that allows TV broadcasts to be received by mobile
devices.
Its official appellation is A/153. Just as the DVB-H
and 1seg are mobile
TV extensions to the DVB-T
and ISDB-T
terrestrial digital TV standards respectively, ATSC-M/H is a suggested extension
to the available digital TV broadcasting standard ATSC
A/53. ATSC is optimized for a fixed reception in the typical North American
environment and uses 8VSB
modulation.
The ATSC transmission scheme is not robust enough against doppler
shift and multipath
radio
interference in mobile environments, and is designed for highly directional
fixed antennas. To overcome these issues, additional channel coding mechanisms
are introduced in ATSC-M/H to protect the signal.
Evolution of
mobile TV standard
Requirements
Several requirements of the new standard were fixed right from the beginning:
- Completely backward compatible to ATSC (A/53),
- Broadcaster can use their available license without additional
restrictions and
- Available legacy ATSC receivers can be used to receive the ATSC (A/53)
standard without any modification.
Proposals
Ten systems from different companies were proposed, and two remaining systems
were presented with transmitter and receiver prototypes:
To find the best solution, the Advanced Television Systems Committee assigned
the Open Mobile Video Coalition (OMVC) to test both systems. The test report was
presented on May 15, 2008. As a result of this detailed work by the OMVC, a
final standard draft was designed by the Advanced Television Systems Committee,
specialist group S-4. ATSC-M/H will be a hybrid. Basically the following
components of the proposed systems are used:
- RF-Layer from the MPH
standard
- Deterministic frame structure from A-VSB
- Signaling of service designed on the base of the established mobile
standards
Candidate standard
On December 1, 2008, the Advanced Television Systems Committee elevated its
specification for Mobile Digital Television to Candidate Standard status. In the
following six months, the industry will test the standard with their potential
customers and start first product developments. Before it becomes an official
standard, additional improvements will be proposed. ATSC members approved the
ratified A/153 standard in October 2009.
8VSB is the 8-level vestigial
sideband modulation method adopted for terrestrial
broadcast of the ATSC
digital
television standard in the United
States and Canada.In
the 6MHz (megahertz)
channel used for broadcast ATSC, 8VSB carries 19.39Mb (megabits)
of usable data per second, although the actual transmitted bit
rate is significantly higher due to the addition of forward
error correction codes. The eight signal levels are
selected with the use of a trellis
encoder. There are also the similar modulations 2VSB,
4VSB,
and 16VSB.
16VSB was notably intended to be used for ATSC digital
cable, but quadrature
amplitude modulation (QAM) has become the industry
standard instead.
PES- Defined
by MPEG
communication protocol. An Elementary
stream is packetized by adding a packet header. The output
of a video encoder is an elementary stream which is then
packetized. Packet protocol allows:
1-
Multiplexing
of the data and to minimize the size of buffers (reduce cost) in receivers.
2-
Error detection and control.
An elementary stream contains
only one kind of data, for example audio or video. The output
of a video encoder is an elementary stream. The output of an
audio encoder is also an elementary stream. Sometimes referred
to as "elementary", "data",
"audio", or "video" bitstreams
or streams. The format of the elementary stream depends upon
the codec or data carried in the stream.
Integrated
Services Digital Broadcasting (ISDB)
is the digital
television (DTV)
and digital audio broadcasting (DAB)
format that Japan
has created to allow radio
and television
stations there to convert to digital.
ISDB is
maintained by the Japanese organisation ARIB.
The standards
can be obtained for free at the Japanese organization DiBEG
website and at ARIB.
The core
standards of ISDB are ISDB-S
(satellite television), ISDB-T(terrestrial),
ISDB-C
(cable) and 2.6GHz
band mobile broadcasting which are all based on MPEG-2
video and audio coding as well as the transport stream
described by the MPEG-2 standard, and are capable of high
definition television (HDTV).
ISDB-T
and ISDB-Tsb
are for mobile reception in TV bands. 1seg
is the name of an ISDB-T service for reception on cell
phones, laptop
computers and vehicles.
The concept was
named for its similarity to ISDN,
because both allow multiple channels of data to be transmitted
together (a process called multiplexing). This is also much
like another digital
radio system, Eureka
147, which calls each group of stations on a transmitter
an ensemble;
this is very much like the multi-channel digital TV standard DVB-T.
ISDB-T operates on unused TV channels, an approach taken by
other countries for TV but never before for radio.
Video and audio
compression
ISDB has adopted
the MPEG-2
video and audio compression system. ATSC and DVB also adopted
the same system. DVB and ISDB also provide for other video
compression methods to be used, including JPEG
and MPEG-4,
although JPEG is only a required part of the MHEG
standard.
Transmission
The various
flavors of ISDB differ mainly in the modulations used, due to
the requirements of different frequency bands. The 12 GHz band
ISDB-S uses PSK modulation, 2.6 GHz band digital sound
broadcasting uses CDM and ISDB-T (in VHF and/or UHF band) uses
COFDM with PSK/QAM.
Interaction
Besides audio
and video transmission, ISDB also defines data connections
(Data broadcasting) with the internet as a return channel over
several media (10Base-T/100Base-T, Telephone line modem,
Mobile phone, Wireless LAN (IEEE 802.11) etc.) and with
different protocols. This is used, for example, for
interactive interfaces like data broadcasting (ARIB STD B-24)
and electronic program guides (EPG).
Interfaces and
Encryption
ISDB describes a
lot of (network) interfaces, but most importantly the Common
Interface for Conditional Access (ARIB STD-B25) with the
Common Scrambling Algorithm (Multi-2) required for
(de-)scrambling TV.
The ISDB CAS
system is operated by a company named B-CAS in Japan; the CAS
card is called B-CAS card. The Japanese ISDB signal is
always encrypted by the B-CAS system even if it is a free TV
program. That is why it is commonly called "Pay per view
system without charge". An interface for mobile reception
is under consideration.
ISDB supports RMP
(Rights management and protection). Since all DTV systems
carry digital data content, a DVD
or HD recorder could easily copy content losslessly, so that a
great deal of pirated content could be circulating the market.
Hollywood
requested copy protection; this was the main reason for RMP.
The content has three modes: “Copy once”, “Copy free”
and “Copy never”. In “Copy once” mode a program can be
stored on a hard disc recorder, but cannot be copied.
Receiver
There are two
types of ISDB receiver: TV
and STB
(Set top box). The aspect ratio of ISDB television is 16:9;
televisions fulfilling these specs are called Hi-vision
TVs. There are three TV types: CRT
(Cathode ray tube), PDP
(Plasma display panel) and LCD
(Liquid crystal display), with LCD being the most popular
Hi-Vision format on the Japanese market right now.
LCD share as
measured by JEITA
in November 2004 was about 60%. While PDP set occupies the
high end market with units that are over 50 inches (1270 mm),
PDP and CRT set shares are about 20% each. CRT set are
considered low end for Hi-Vision.
STB is sometimes
referred to as digital tuner. High-end ISDB STB have several
interfaces:
-
B-CAS card
interface to de-scramble.
-
IR
interface jack
for controlling a VHS or DVD player.
Problems
Though ISDB is a
feature-rich system, many problems have surfaced recently.
Copy Protection
Technology
Almost every TV
broadcast (including free TV) are encrypted with
"Copy-Once", which allows users to record to a
digital media (D-VHS, DVD, HDD, etc) but does not allow
dubbing to another digital media. On the other hand, the
"Copy-Once" technology does not prohibit all types
of dubbing. It is possible to dub to an analog media (such as
standard VHS) and if recorded to an HDD, it will allow users
to "Move" the contents to a D-VHS, but not copy.
Many users are
also very worried about the recent news of severe protection
in the future. There are modes in ISDB to now allow the output
of signal from an Analog connector (D-connector, Component,
Composite, S-Video, etc). There are already plans to not allow
analog output for "Copyright Protection" reasons.
(Same as Blu-ray and HD-DVD) This will make all currently sold
STB Tuners, and the majority of LCD/Plasma TVs without HDMI
inputs unusable. Plus all analog VHS, D-VHS that can only
record via analog input, and all DVD players will also become
unusable. These more limiting copy protection technologies
will all start after analog broadcasting ends (when there
won't be any choice for viewers). Currently, no financial
assistance schemes have been announced, and viewers without
proper devices will be forced to buy a new compatible TV or
set top box in order to view ISDB broadcasts. Though not
clear, it is said that there are also plans to protect all
programs with "Copy-Never".
B-CAS Card
The B-CAS card
is required to decode all broadcasts. These cards are included
with every digital TV or Tuner at no charge. To use this card,
you must agree to the statement written on the registration
card. Despite the fact that the card must be inserted to watch
TV, if you don't agree to the statement, then the user cannot
watch digital broadcasts. Essentially, users are
"forced" to agree with the statement. Though
registration is not required, it is recommended to fully enjoy
interactive programs. However, many viewers worry about the
leaking of personal information, and the power/rights the TV
stations have to access personal information for almost every
citizen in Japan.
Services
-
One HDTV or up
to three SDTV services within one channel.
-
Provides Data
broadcasting.
-
Interactive
services via Telephone Line or 10Base-T Broadband Internet.
-
EPG
(Electronic
Program Guide)
-
Ability to send
firmware patches for the TV/tuner
ISDB-S
History
Japan started
digital broadcasting using the DVB-S standard by PerfecTV in
October/1996, and DirecTV in December/1997, with communication
satellites. Still, DVB-S did not satisfy the requirements of
Japanese broadcasters, such as NHK,
key commercial broadcasting stations like Nippon
Television, TBS,
Fuji
Television, tv
asahi, TV
Tokyo, and WOWOW
(Movie-only Pay-TV broadcasting). Consequently, ARIB
developed the ISDB-S standards. The requirements were HDTV
capability, interactive services, network access and effective
frequency utilization, and other technical requirements. The
DVB-S standard allows the transmission of a bit stream of
roughly 34 Mbit/s with a satellite transponder, which means
the transponder can send one HDTV channel. Unfortunately, the
NHK broadcasting satellite had only four vacant transponders,
which led ARIB and NHK to develop ISDB-S: The new standard
could transmit at 51 Mbit/s with a single transponder, which
means that ISDB-S is 1.5 times more efficient than DVB-S and
that one transponder can transmit two HDTV channels, along
with other independent audio and data. Digital satellite
broadcasting (BS digital) was started by NHK and followed
commercial broadcasting stations on 1
December 2000.
Today, SKY PerfecTV!, successor of Skyport TV, and Sky D, CS
burn, Platone, EP, DirecTV, J Sky B, and PerfecTV!, adopted
the ISDB-S system for use on the 110 degree (east longitude)
wide-band communication satellite.
Technical
specification
Summary of ISDB-S
(Satellite digital broadcasting)
Transmission
channel coding
|
Modulation
|
TC8PSK, QPSK,
BPSK
(Hierarchical transmission)
|
Error correction
coding
|
Inner
coding:Trellis [TC8PSK] and Convolution
Outer coding :RS(204,188);
TMCC:Convolution
coding+RS
|
Time domain
multiplexing
|
TMCC
|
Conditional
Access
|
Multi-2
|
Data
broadcasting
|
ARIB STD B-24 (BML,
ECMA script)
|
Service
information
|
ARIB STD B-10
|
Multiplexing
|
MPEG-2 Systems
|
Audio coding
|
MPEG-2 Audio(AAC)
|
Video coding
|
MPEG-2 Video
|
Channel
Frequency and
channel specification of Japanese Satellites using ISDB-S
Method
|
BS digital
broadcasting
|
Wide band CS
digital broadcasting
|
Frequency band
|
11.7 to 12.2 GHz
|
12.2 to 12.75
GHz
|
Transmission bit
rate
|
51 Mbit/s
(TC8PSK)
|
40 Mbit/s (QPSK)
|
Transmission
band width
|
34.5 MHz*
|
34.5 MHz
|
-
Compatible with
27 MHz band satellite transponder for analog FM broadcasting.
ISDB-T
History
HDTV was
invented at NHK
STRL.
The research of HDTV started as early as in the 1960s, though
only in 1973 a standard was proposed to the ITU-R (CCIR). In
the 1980's, the television camera, high definition cathode-ray
tube, video tape recorder and editing equipment among others
were developed. In 1982 NHK developed MUSE (Multiple sub-nyquist
sampling Encoding), the first HDTV video compression and
transmission system. MUSE
adopted digital video compression system, but for transmission
frequency
modulation had been adopted after a digital-to-analog
converter converted the digital signal. In 1987, NHK made
demonstration of MUSE in the Washington D.C and NAB. The
demonstration made great impression on the U.S. As a result of
this, the U.S. developed ATSC,
a terrestrial digital DTV system. Europe also developed their
own DTV system, DVB.
Although the DVB-T service started operating a few weeks later
than the ATSC system, it quickly outstripped ATSC in terms of
user base. Japan started R&D of a completely digital
system in the 1980s that led to ISDB. Japan started
terrestrial digital broadcasting using ISDB-T standard by NHK
and commercial broadcasting stations on the 1
December 2003.
Feature
ISDB-T is
characterized by the following features:
-
ISDB-T can
transmit a HDTV
channel and a mobile phone channel within the 6 MHz bandwidth
usually reserved for TV transmissions.
-
ISDB-T allows to
switch to two or three SDTV channels instead of one HDTV
channel (multiplexing SDTV channels).
-
The combination
of these services can be changed at anytime.
-
ISDB-T provides
interactive services with data broadcasting.
-
ISDB-T provides EPG
(Electronic Program Guides).
-
ISDB-T supports
internet access as a return channel that works to support the
data broadcasting. Internet access is also provided on mobile
phones.
-
ISDB-T provides SFN
(Single frequency Network) and on-channel
repeater technology. SFN makes efficient utilization of
the frequency resource (spectrum).
-
ISDB-T provides
robustness to multipath
interference ("ghosting").
-
ISDB-T provides
robustness to impulse
noises that come from motor vehicles and power lines in
urban environments.
-
ISDB-T allows
HDTV to be received on moving vehicles at over 100 km/h; DVB-T
can only receive SDTV
on moving vehicles, while ATSC
can not be received on moving vehicles at all.
-
1seg
is a mobile
terrestrial digital audio/video broadcasting service in Japan.
Adoption
ISDB-T was
adopted in commercial transmissions in Japan in December 2003.
It comprises a market of about 100 million television sets.
ISDB-T had 10 million subscribers by the end of April 2005.
Along with the wide use of ISDB-T, the price of STB is getting
low. The price of ISDB-T STB in lower end of the market is ¥19800
that is worth $169 at 19 April 2006. (Japanese)
uniden
Brazil*,
which currently uses an analogue
TV system (PAL-M) that slightly differs from any other
country's, has chosen ISDB-T for its DTV
format, calling it SBTVD-T Sistema Brasileiro de Televisão
Digital- Terrestre. Other than that, there are no other countries
that are considering ISDB. Possibly because ISDB Tuners and TVs
are way too expensive compared to other formats. However, it does
seem to have an advantage over ATSC and DVB-T in reception tests.
The ABERT/SET group in Brazil did system comparison tests of DTV
under the supervision of the CPqD
foundation. The comparison tests were done under the direction of
a work group of SET
(the Brazilian Television Engineering Society) and ABERT
(the Brazilian Association of Radio and Television Broadcasters).
The ABERT/SET group selected ISDB-T as the best in the digital
broadcasting systems among ATSC, DVB-T and ISDB-T. ISDB-T was
pointed out as the most flexible of all for better answering the
necessities of mobility and portability. It is most efficient for
mobile and portable reception. In June 29, 2006, Brazil announced
ISDB as the chosen standard for Digital TV transmissions, to be
fully implemented until 2016. See SBTVD.
-
Argentina (and
other south-american countries) may adopt the Brazilian model
Technical
specification
Segment struture
ARIB has
developed the segment structure called OFDM
(see figure). ISDB-T divides the frequency band of one channel
into thirteen segments. Broadcaster can select the combination
of segments to use: this choice of segment structure allows
for flexibility of services. For example, ISDB-T can transmit
a LDTV
and a HDTV using one TV channel or change to 3 SDTV, a switch
that can be performed anytime. ISDB-T can also change the
modulation scheme at the same time.
s 13 |
s 11 |
s 9 |
s 7 |
s 5 |
s 3 |
s 1 |
s 2 |
s 4 |
s 6 |
s 8 |
s 10 |
s 12 |
-
-
-
-
-
-
FIGURE
Spectrum
segment structure of ISDB-T
Summary of ISDB-T
Transmission
channel coding
|
Modulation
|
64QAM-OFDM,
16QAM-OFDM,
QPSK-OFDM,
DQPSK-OFDM
(Hierarchical
transmission)
|
Error correction
coding
|
Inner coding,
Convolution
7/8,3/4,2/3,1/2
Outer coding :RS(204,188)
|
Guard interval
|
1/16,1/8,1/4
|
Interleaving
|
Time, Frequency,
bit, byte
|
Frequency domain
multiplexing
|
BST-OFDM
(Segmented structure OFDM)
|
Conditional
Access
|
Mutli-2
|
Data
broadcasting
|
ARIB STD B-24 (BML,
ECMA script)
|
Service
information
|
ARIB STD B-10
|
Multiplexing
|
MPEG-2 Systems
|
Audio coding
|
MPEG-2 Audio (AAC)
|
Video coding
|
MPEG-2 Video
|
MPEG-4 AVC
/H.264*
|
-
H.264 used in
one segment broadcasting for Mobile phone.
Channel
Specification of
Japanese terrestrial digital broadcasting using ISDB-T
Method
|
terrestrial
digital broadcasting
|
Frequency band
|
VHF/UHF, Super
high band
|
Transmission bit
rate
|
19 Mbit/s(64QAM)
|
Transmission
band width
|
5.6 MHz*
|
-
Compatible to 6
MHz band terrestrial analog TV broadcasting.
2.6 GHz Mobile
satellite digital audio/video broadcasting
MobaHo!
is the name of
the services that uses the Mobile satellite digital audio
broadcasting specifications. MobaHo!
started its service on 20th October, 2004.
ISDB-Tsb
ISDB-Tsb is the
terrestrial digital sound broadcasting specification. The
technical specification is the same as ISDB-T. ISDB-Tsb
supports the coded
transmission of OFDM siginals.
ISDB-C
ISDB-C is cable
digital broadcasting specification. The technical
specification is developed by JCTEA.
Standards
ARIB
and JCTEA
developed the following standards. Some part of standards are
located on the pages of ITU-R
and ITU-T.
Channel
|
Communication
Satellite television digital broadcasting
|
Broadcasting
/Communication
Satellite
television
digital
broadcasting
|
Terrestrial
television digital broadcasting
|
Satellite Sound
digital broadcasting
|
Terrestrial
Sound digital broadcasting
|
Cable
television
digital
broadcasting
|
Nick name
|
-
|
ISDB-S
|
ISDB-T
|
2.6 GHz mobile
broadcasting
|
ISDB-Tsb
|
64QAM,
Trans-modulation
(ISDB-C)
|
Transmission
|
DVB-S
|
ARIB
STD-B20,
ITU-R BO.1408
|
ARIB
STD-B31,
ITU-R BT.1306-1
|
ARIB STD-B41
|
ARIB STD-B29,
ITU-R BS.1114
|
ITU-T J.83 Annex
C, J.183
|
Receiver
|
ARIB STD-B16
|
ARIB STD-B21
|
ARIB STD-B42
|
ARIB STD-B30
|
JCTEA STD-004,
STD-007
|
Server type
broadcasting
|
-
|
ARIB STD-B38
|
-
|
Conditional
access
|
-
|
ARIB STD-B25
(Muti-2)
|
JCTEA STD-001
|
Service
information
|
-
|
ARIB STD-B10
|
JCTEA STD-003
|
Data
broadcasting
|
-
|
ARIB STD-B24 (BML),
ARIB STD-B23 (EE or MHP like)
|
-
|
Video/Audio
compression and multiplexing
|
MPEG-2
|
ARIB STD-B32
(MPEG)
|
-
|
Technical report
|
-
|
ARIB TR-B13
|
ARIB TR-B14
|
-
|
-
|
-
|
Table of
terrestrial HDTV transmission systems
Table 1: Main
characteristics of three DTTB systems
Systems
|
ATSC 8-VSB
|
DVB COFDM
|
ISDB BST-COFDM
|
Source coding
|
Video
|
Main profile
syntax of ISO/IEC 13818-2 (MPEG-2 - video)
|
Audio
|
ATSC Standard
A/52 (Dolby AC-3)
|
ISO/IEC 13818-2
(MPEG-2 – layer II audio) and Dolby AC-3
|
ISO/IEC 13818-7
(MPEG-2 – AAC audio)
|
Transmission
system
|
Channel coding
|
|
Outer coding
|
R-S (207, 187, t
= 10)
|
R-S (204, 188, t
= 8)
|
Outer
interleaver
|
52 R-S block
interleaver
|
12 R-S block
interleaver
|
Inner coding
|
Rate 2/3 trellis
code
|
Punctured
convolution code: Rate 1/2, 2/3,3/4, 5/6, 7/8 Constraint
length = 7, Polynomials (octal) = 171, 133
|
Inner
interleaver
|
12 to 1 trellis
code interleaver
|
Bit-wise
interleaving and frequency interleaving
|
Bit-wise
interleaving, frequency interleaving and selectable time
interleaving
|
Data
randomization
|
16-bit PRBS
|
16-bit PRBS
|
16-bit PRBS
|
Modulation
|
8-VSB and 16-VSB
|
COFDM
QPSK, 16QAM and 64QAM
Hierarchical modulation: multi-resolution constellation (16QAM
and 64 QAM)
Guard interval: 1/32, 1/16, 1/8 & 1/4 of OFDM symbol
2 modes: 2k and 8k FFT
|
BST-COFDM with
13 frequency segments
DQPSK, QPSK, 16QAM and 64QAM
Hierarchical modulation: choice of three different modulations
on each segment
Guard interval: 1/32, 1/16, 1/8 & 1/4 of OFDM symbol
3 modes: 2k, 4k and 8k FFT
|
|

ISDB-T System
- ISDB (Integrated
Digital Services Digital Broadcasting) is a new type of digital
broadcasting intended to provide audio, video, and multimedia services.
T is Terrestrial.
- ISDB-T system was developed by the Association of
Radio Industries and Businesses (ARIB)
in Japan.
- ISDB-T is one of ISDB family.
- ISDB-T uses a modulation method referred to as Band
Segmented Transmission (BST) OFDM
ARIB Technical Reports (published in June, 2007)
ISDB-T (Integrated Service Digital Broadcasting - Terrestrial) has been
developed and now on service in Japan, and adopted by Brazil.
ISDB-T proves best performances in Japanese DTTB service for more than 3
years.
Since Dec. 2003, start of Japanese DTTB service, DTTB service is rapidly
migrated because of its advantages, and new service, named
"One-seg", portable reception service in same channel, has been
started from April 2006.
But, because of late start of ISDB-T, ISDB-T is not so popular in the world,
so, we will submit this technical report to South America countries to
understand the ISDB-T system and its advantages on technical aspect.
Now, 3 major DTTB( Digital Terrestrial TV Broadcasting) systems exist.
These are called:
|
1- ATSC: Advanced Television System Committee,
Developed in USA, and now used. |
|
2- DVB-T: Digital Video Broadcasting –
Terrestrial, developed in EU, and now used. |
|
1- ISDB-T: Integrated Service Digital
Broadcasting – Terrestrial, developed in Japan and now used in
Japan and Brazil. |
|
1-
structure of technical
standard for digital broadcasting |
Generally speaking, Digital broadcasting
system is composed by 3 functional blocks, (1)Source coding block,
(2)Multiplex block, and (3)transmission coding block. |
|
2-
About ISDB-T
transmission system |
Japanese digital terrestrial broadcasting
system adopts excellent technologies for transmission system. |
|
3-
Outline of
transmission parameter |
ISDB-T transmission system has a
flexibility for the purpose of broadcasting service. |

 |
DVB
Abbreviations |
 |
|
|
A/D - Analog/Digital
A/V - Audio/Video
AAC - Advanced Audio Coding
AAL - ATM Adapter Layer
ABR - Available Bit Rate
AC - Alternating Current
ADC- Analog to Digital Converter
ADD/DROP-MUX - Add and Drop Multiplexer
ADPCM - Adaptive Differential Pulse Code Modulation
ADR - Astra Digital Radio
ADSL - Asymmetric Digital Subscriber Line
AES - Audio Engineering Society
AF - Adaptation Field
AF - Audio Frequency
AFC - Automatic Frequency Control
AGC - Automatic Gain Control
AGDT - Additional Guide Data Table
AGL - Above Ground Level
AM - Amplitude Modulation
ANSI - American National Standards Institute
API - Application Programming Interface
APS - Antenna Positioning System
AR - Activity Ratio
ASCII - American Standard Code for Information Interchange
ASI - Asynchronous Serial Interface
ASIC - Application Specific Integrated Circuit
ASK - Amplitude Shift Keying
ATM - Asynchronous Transfer Mode
ATSC - Advanced Television Systems Committee
ATSC-MPG - ATSC-Master Guide Table
ATV - Advanced Television
B-frame - Bi-directional prediction frame
BAN - Broadband Access Network
BAP - Body Animation Parameters
BAT - Bouquet Association Table
BCD - Binary Coded Decimal
BDP - Body Definition Parameters
BER - Bit Error Rate
BERT - Bit Error Rate Test
BNC - Bayonet-Neill-Concelman (connector)
BOM - Begin of Message
BP - Band-Pass
BPSK - Binary Phase Shift Keying
BRA - Basic Rate Access
BRR - Bit Rate Reduction
BSAC - Bit-Sliced Arithmetic Coding
BTA - Broadcasting Technology Association
BW - Bandwidth
C/I - Carrier to Interference Ratio
C/N - Carrier to Noise Ratio
CA - Conditional Access
CAM - Conditional Access Module
CAS - Conditional Access System
CAT - Conditional Access Table
CATV - Community Antenna Television (Cable Television)
CCD - Charge Coupled Device
CCIR - Comité Consultatif International des Radiocommunications (French, since 1993: ITU-R)
CCIR - Consultative Committee for International Radiocommunications
CCITT - Comité Consultatif International Téléphonique et Télégraphique (French, since 1993: ITU-R)
CD - Compact Disc
CDA - Confidential Disclosure Agreement
CD-DA - Compact Disc - Digital Audio
CD-I - Compact Disc - Interactive
CDMA - Code Division Multiple Access
CD-ROM - Compact Disc - Read Only Memory
CE - Core Experiment
CEC - Commission of the European Community
CEI - Commission Electrotechnique Internationale
CELP - Code Excited Linear Prediction
CEMA - Consumer Electronics Manufacturers Association
CEN - Comité Européen de Normalisation
CENELEC - Comité Européen de Normalisation Electrotechnique
CEPT - Conférence Européenne des Administrations des Postes et des Télécommunications (French), European Conference of Postal and Telecommunications Administrations
CI - Common Interface
CIF - Common Intermediate Format
CIT - Channel Information Table
CLK - Clock
CLUT - Colour Look-Up Tables
CMIP - Common Management Information Protocol
CMOS - Complementary Metal Oxide Semiconductor
CNR - Carrier to Noise Ratio = C/N
CODEC -Coder-Decoder
COFDM - Coded Orthogonal Frequency Division Multiplexing
CPB - Constrained Parameter Bitstream
CPE - Customer Premises Equipment
CPS - Constrained Parameter Set
CPU - Central Processing Unit
CRC - Cyclic Redundance Check
CRT - Cathode Ray Tube
CSA - Common Scrambling Algorithm
CTB - Composite Triple Beat
CW - Control Word
D/I - Drop and Insert
DAB - Digital Audio Broadcasting
DAC - Digital to Analog Converter
DAI - DMIF-Application Interface
DAPSK - Differential Amplitude Phase Shift Keying
DAVIC - Digital Audio-Visual Council
dB - Decibel
DBS - Direct Broadcast Satellite
DC - Direct Current
DCC - Digital Communications Channel
DCC - Digital Compact Cassette
DCE - Data Communication Equipment
DCO - Digital Controlled Oscillator
DCT - Discrete Cosine Transform
DDR - Digital Disk Recorder
DDS - Digital Data Service
DECT - Digital Enhanced Cordless Telecommunications
DEMOD - Demodulator
DEMUX - Demultiplexer
DFD - Displayed Frame Difference
DIP - Descriptive Information Parcel
DIS - Draft International Standard
DIT - Discontinuity Information Table
DMA - Direct Memory Access
DMIF - Delivery Multimedia Integration Framework
DNI - DMIF Network Interface
DNS - Domain Name Server
DPCM - Differential Pulse Code Modulation
DPSK - Differential Phase Shift Keying
DRAM - Dynamic Random Access Memory
DRO - Dielectric Resonator Oscillator
DS - DMIF signalling
DSBSC - Double Sideband Suppressed Carrier
DSC - Digital Serial Components
DSM-CC - Digital Storage Media - Command and Control
DSNG - Digital Satellite News Gathering
DSP - Digital Signal Processor
DSR - Digital Satellite Radio
DSS - Digital Satellite System
DTA - Data Terminal Access
DTC - Data Transmission Code
DTE - Data Terminal Equipment
DTH - Direct to Home (Satellite reception)
DTS - Decoding Time Stamp
DTTB - Digital Terrestrial Television Broadcasting
DTTV - Digital Terrestrial Television
DTTV-SA - Digital Terrestrial Television - Systems Aspects
DTV - Digital Television
DVB - Digital Video Broadcasting
DVB-ASI - Digital Video Broadcasting - Asynchronous Serial Interface
DVB-C - DVB-Cable
DVB-CA - DVB-Conditional Access
DVB-CS - DVB-Cable Satellite Master Antenna Television Distribution System
DVB-Data - DVB-Data Broadcasting
DVB-LVDS - Digital Video Broadcasting - Low Voltage Differential Signalling
DVB-MC - DVB-Microwave Cable Based
DVB-MG - DVB-Measurement Group
DVB-MS - DVB-Microwave Satellite Based
DVB-PI - DVB-Physical Interface Group
DVB-RCC - DVB-Return Channel Cable
DVB-S - Digital Video Broadcasting - Satellite
DVB-SI - Digital Video Broadcasting - Service Information
DVB-T - Digital Video Broadcasting - Terrestrial
DVC - Digital Video Cassette
DVD - Digital Video Disc
DVI - Digital Video Interactive
EACEM - European Association of Consumer Electronics Manufacturers
EAV - End of Active Video
EBU - European Broadcasting Union(UER, French)
ECL - Emitter Coupled Logic
ECM - Entitlement Control Message
EDTV - Enhanced Definition Television
EEPROM - Electrically Erasable Programmable Read Only Memory
EHF - Extremely High Frequency
EIRP - Effective Isotropic Radiated Power
EIT - Event Information Table
EMM - Entitlements Management Message
EN - European Norms
EOM - End OF Message
EPG - Electronic Program Guide
ERC - European Regulatory Committee
ERO - European Radio Communications Office
ES - Elementary Stream
ESA - European Space Agency
ETR - ETSI Telecommunication Report
ETS - European Telecommunication Standard
ETSI - European Telecommunications Standards Institute
EVM - Error Vector Magnitude
EX-OR - Exclusive Order (XOR)
F/D - Focal Distance to Diameter Ratio
FAP - Facial Animation Parameters
FAQ - Frequently Asked Questions
FBA - Facial and Body Animation
FCAPS - Faults, Configuration, Accounting, Performance and Security management
FCC - Federal Communications Commission
FDDI - Fiber Distributed Data Interface
FDM - Frequency Division Multiplex
FDMA - Frequency Division Multiple Access
FDP - Facial Definition Parameters
FEC - Forward Error Correction
FFT - Fast Fourier Transform
FM - Frequency Modulation
FPGA - Field Programmable Gate Arrays
FSK - Frequency Shift Keying
FSS - Fixed Satellite Service
FTP - File Transfer Protocol
FTTB - Fibre To The Building
FTTC - Fibre To The Curb
FTTH - Fibre To The Home
G/T - Gain over Noise Temperature
Gb/s - Gigabits per Second
GDMO - Guidelines for the Definition of Managed Objects
GFC - Generic Flow Control
GHz - Gigahertz
GIF - Graphics Interchange Format
GMT - Greenwich Mean Time
GOP - Group of Pictures
GPS - Global Positioning System
GSM - Global System for Mobile Communications
GSO - Geo-Synchronous Orbit
GSTN - General Switched Telephone Network
HAN - Home Access Network
HDCL - High-speed Data link Channel
HDD - Hard Disk Drive
HD-MAC - High Definition Multiplexed Analogue Components
HDSL - High-speed Digital Subscriber Line
HDTV - High Definition Television
HEC - Headed Error Control
HEX - Hexadecimal
HFC - Hybrid Fibre Coax
HILN - Harmonic Individual Line and Noise
HLN - Home Local Network
HP - Horizontal Polarization
HPA - High Power Amplifier
HTML - HyperText Mark-up Language
HTTP - HyperText Transfer Protocol
HVXC - Harmonic Vector Excitation Coding
I-frame - Intra-coded frame
I/O - Input/Output
I/Q - In/Quadratur-Phase
IBO - Input Backoff
IC - Integrated Circuit
ICTSB - Information and Communication Technology Standards Board
ID - Identification, Identifier
IDCT - Inverse Discrete Cosine Transform
IDFT - Inverse Discrete Fourier Transform
IEC - International Electrotechnical Committee
IEEE - Institute of Electrical and Electronic Engineers
IETF - Internet Engineering Task Force
IF - Intermediate Frequency
IMUX - Input Multiplexer
IP - Internet Protocol
IPI - Intellectual Property Identification
IPP - Internet Presence Provider
IPPV - Impulse Pay per View
IPR - Intellectual Property Rights
IR - Infra Red
IRD - Integrated Receiver Decoder
IRE - Institute of Radio Engineers
IS - International Standard
ISA - Industry Standard Architecture
ISDB-T - Integrated Services Digital Broadcasting-Terrestrial
ISDN - Integrated Services Digital Network
ISI - Inter-Symbol Interference
ISL - Intersatellite Link
ISO - International Standards Organization
ISP - Internet Service Provider
ITFS - Instructional Television Fixed Service
ITU - International Telecommunications Union(UIT, French)
ITU-R - International Telecommunications Union -Radiocommunication
ITU-T - International Telecommunications Union -Telecommunication
ITU-TS - International Telecommunications Union-Telecommunication Standardisation Sector
JPEG - Joint Photographic Experts Group
JTC - Joint Technical Committee
kb/s - Kilobits per second
kHz - Kilohertz
KLT - Karhunen-Loeve Transform
LAN - Local Area Network
LAR - Logarithmic Area Ratio
LC - Low Complexity
LCD - Liquid Crystal Display
LDTV - Low Definition Television
LED - Light Emitting Diode
LMDS - Local Multipoint Distribution System
LNA - Low Noise Amplifier
LNB - Low Noise Block
LO - Local Oscillator
LOS - Line of Sight
LP - Low Power
LPC - Linear Predictive Coding
LSB - Least Significant Bit
LSP - Line Spectral Pairs
LTP - Long Term Prediction
LVDS - Low Voltage Differential Signaling
MAC - Media Access Control
MAC - Multiplexed Analog Components
MATV - Master Antenna Television
Mb/s - Megabits per second
MBPS - Megabits per second
MBU - Multiple Business Unit
MC - Multichannel (MPEG-2 Audio)
MCNS - Multimedia Cable Network Systems
MCPC - Multi Channel per Carrier
MCS - Multipoint Communications System
MCU - Multipoint Control Unit
MDCT - Modified Discrete Cosine Transform
MDS - Multipoint Distribution Service
MFN - Multiple Frequencies Network
MHEG - Multimedia and Hypermedia Expert Group
MHP - Multimedia Home Platform
MHz - Megahertz
MIB - Management Information Base
MIDI - Musical Instrument Digital Interface
MIME - Multipurpose Internet Mail Extensions
MIPS - Mega/Million Instructions Per Second
M-JPEG - Motion-JPEG (Joint Photographic Experts Group)
MMDS - Multichannel Microwave Distribution System
MMDS - Multichannel Multipoint Distribution System
MMI - Man-Machine-Interface
MODEM - Modulator/Demodulator
MOPS - Mega/Million Operations Per Second
MP@ML - Main Profile at Main Level
MPEG - Moving Picture Experts Group
MPEG-J - Framework for MPEG Java API’s
MPG - Master Guide Table
MPTS - Multiple Programs Transport Stream
MR - Multi-Resolution
MR-QAM - Multi-Resolution QAM
MSB - Most Significant Bit
MSDL - MPEG 4 Systems and Description Language
MSO - Multi-System Operator
MTBF - Mean Time Between Failures
MTS - Multiple Transport Stream
MUSE - Multiple-Subsampling-Encoding
MUSICAM - Masking Pattern Adapted Universal Subband Integrated Coding and Multiplexing
MUX - Multiplexer
MVDS - Multipoint Video Distribution System (40 GHz Band)
MVPD - Multichannel Video Programming Distributor
NA - Network Adapter
NAB - National Association of Broadcasters
NBC - Non-Backwards Compatible Audio (MPEG-2 Audio)
NHK - Nippon Hoso Kyokai, Japanese broadcaster
NIC - Network Information Centre
NIT - Network Information Table
NM - Network Management
NMF - Network Management Forum
NNI - Network Network Interface
NRZ - Non-Return-to-Zero
NTSC - National Television System Committee
NVOD - Near Video On Demand
OBO - Output Backoff
OCAM - Open Conditional Access Module
OD - Object descriptor
OFDM - Orthogonal Frequency Division Multiplex
OFS - Operational Fixed Service
OMT - Rumbaugh Object Modeling Technique
OMUX - Output Multiplexer
OSD - On Screen Display
OSI - Open Systems Interconnection
P-frame - Predicted frame
PAL - Phase Alternating Line
PALplus - Advanced PAL
PAT - Program Association Table
PC - Personal Computer
PCI - Program Controlled Interrupt
PCM - Pulse Code Modulation
PCMCIA - Personal Computer Memory Card International Association
PCR - Program Clock Reference
PD - Phase Discriminator
PDH - Plesiochronous Digital Hierarchy
PDM - Pulse Duration Modulation
PDU - Protocol Data Unit
PES - Packetized Elementary Stream
PH - PES Header
PI - Professional Interface
PID - Packet Identifier
PIN - Personal Identification Number
PIP - Privat Information Parcel
PL - Payload
PLL - Phase Locked Loop
PMT - Program Map Table
POP - Point of Presence
POTS - Plain Old Telephone Service
PPP - Point to Point Protocol
PPV - Pay per View
PRA - Primary Rate Access
PRBS - Pseudo-Random Binary Sequences
PS - Program Stream
PSD - Power Spectral Density
PSI - Program Specific Information
PSK - Phase Shift Keying
PSNR - Peak Signal to Noise Ratio
PSS - Procedures, Specifications, Standards
PSTN - Public Switched Telephone Network
PTI - Payload Type Indicator
PTS - Presentation Time Stamp
PTT - Post, Telegraph and Telephone
PVRG - Portable Video Research Group
QAM - Quadrature Amplitude Modulation
QCIF - Quarter Common source Intermediate Format
QEF - Quasi Error-Free
QOS - Quality of Service
QPSK - Quadrature Phase Shift Keying
RAID - Redundant Array of Independent Disks
RAM - Random Access Memory
RC - Remote Control
RES - Residential
RF - Radio Frequency
RFI - Radio Frequency Interference
RFP - Request for Proposal
RFP - Request for Proposal
RGB - Red Green Blue
RJ - Registered Jack (connector)
RLC - Run Length Coding
RMA - Random Multiple Access
ROM - Read Only Memory
RPC - Remote Procedure calls
RS - Reed-Solomon (-Code)
RSA - Response Service Area
RSH - Response Station Hub
RST - Running Status Table
RTSP - Real Time Streaming Protocol
RTTP - Real Time Transport Protocol
S/N - Signal to Noise Ratio
SAAL - Signaling ATM Adaption Layer
SAR - Successive Approximation Register
SAS - Subscriber Authorization System
SAV - Start of Active Video
SAW - Surface Acoustic Wave (Filter)
SB - Steering Board
SC - Subcommittee
SCPC - Single Channel per Carrier
SCR - System Clock Reference
SCSI - Small Computer Standard Interface
SDH - Synchronous Digital Hierarchy
SDI - Serial Digital Interface
SDS - Satellite Digital Systems
SDT - Service Description Table
SDTV - Standard Definition Television
SECAM - Séquentielle à Mémoire(French), Sequential with memory(television)
SER - Symbol Error Rate
SFN - Single Frequency Network
SGML - Standard Graphical Mark-up Language
SI - Service Information
SIF - Source Input Format
SIMD - Single Instruction Multiple Data
SIMS - Service Information Management System
SIT - Service Information Table
SL - Synchronization Layer
SLA - Service Level Agreement
SLM - Signal Level Meter
SMATV - Satellite Master Antenna Television
SMPTE - Society of Motion Picture and Television Engineers
SMS - Subscriber Management System
SNA - System Network Architecture
SNG - Satellite News Gathering
SNHC - Synthetic Natural Hybrid Coding
SNMP - Simple Network Management Protocol
SNR - Signal to Noise Ratio (= S/N)
SOD - Service on Demand
SOHO - Small Office, Home Office
SONET - Synchronous Optical Network
SPI - Synchronous Parallel Interface
SPTS - Single Program Transport Stream
SRAM - Static Read Access Memory
SS - Solid State
SSI - Synchronous Serial Interface
SSPA -Solid State Power Amplifier
ST - Stuffing Table
STB - Set Top Box
STC - System Time Clock
STL - Studio Transmitter Link
STM - Synchronous Transport Module
STP - Shielded Twisted Pair
SW - Short Wave
T/F coder - Time/Frequency Coder
TA - Terminal Adapter
TCP - Transmission Control Protocol
TCP/IP - Transmission Control Protocol / Internet Protocol
TDM - Time Division Multiplexing
TDMA - Time Division Multiple Access
TDT - Time Date Table
TI - Terrestrial Interference
TIFF - Tagged Image File Format
TM - Technical Module( within DVB-Project)
TMN - Telecommunications Management Network
TOT - Time Offset Table
TP - Transport Packet
TPO - Transmitter Power Output
TPS - Transmission Parameter Signaling
TS - Transport Stream
TSINP - Transport Stream Input
T-STD - Transport Stream System Target Decoder
TTL _ Transistor Transistor Logic
TTS - Text to Speech
TV - Television
TVRO - Television Receive Only
TWTA - Traveling Wave Tube Amplifier
TX - Transmitter
UDP - User Datagram Protocol
UER - Union Européenne de Radio-Télévision(French)
UHF - Ultra High Frequency, 470 - 862 MHz (Television)
UIT - Union Internationale des Télécommunications(French)
UMTS - Universal Mobile Telecommunication System
UPS - Uninterruptable Power Supply
URD - User Requirements Document
URL - Uniform Resource Locator
UTC - Universal Time, Coordinated
UTO - Unshielded Twisted Pair
VBI - Vertical Blank Interleave
VBR - Variable Bit Rate
VBV - Video Buffer Verifier (MPEG-2 Video)
VC - Virtual Channel
VCO - Voltage Controlled Oscillator
VCR - Video Cassette Recorder
VDSL - Very high-bit rate Digital Subscriber Line
VHF - Very High Frequency
VHS - Video Home System
VLBV - Very Low Bitrate Video
VLC - Variable Length Coding
VLD - Variable Length Decoder
VLSI - Very Large Scale Integration
VMS - Virtual Memory System
VOD - Video on Demand
VP - Vertical Polarization
VP - Virtual Path
VPI - Virtual Path Indicator
VRML - Virtual Reality Modeling Language
VSAT - Very Small Aperture Satellite Transmission
VSAT - Very Small Aperture Terminal
VSB-AM - Vestigial Sideband Amplitude Modulation
VS - Voltage Standing
WR - Wave Ratio
VTO - Voltage Tuned Oscillator
VTR - Video Tape Recorder
WAN - Wide Area Network
WCA - Wireless Cable Association International
WCS - Wireless Communication Service
WG - Working Group
WGDTB - Working Group on Digital Television Broadcasting
WLL - Wireless Local Loop
WMN - Wireless Multimedia Network
WPM - Wireless PC Modem
WWW - World Wide Web
WYSIWYG - What You See Is What You Get
Y - Luminance
|
 |
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Service |
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or come up with a solution for your application. Alitronika
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