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.




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? 
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?
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.
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:

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).

For More information on PCI and PCIe, refer to the following articles on www.pcgearlab.com

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


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.


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.


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.


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.


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.


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.


  1. One HDTV or up to three SDTV services within one channel.
  2. Provides Data broadcasting.
  3. Interactive services via Telephone Line or 10Base-T Broadband Internet.
  4. EPG (Electronic Program Guide)
  5. Ability to send firmware patches for the TV/tuner



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)

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 AudioAAC
Video coding MPEG-2 Video


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.



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.


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.


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

channel coding
Modulation 64QAM-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.


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 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 is cable digital broadcasting specification. The technical specification is developed by JCTEA.


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


Terrestrial television digital broadcasting Satellite Sound digital broadcasting Terrestrial Sound digital broadcasting Cable


digital broadcasting
Nick name - ISDB-S ISDB-T 2.6 GHz mobile broadcasting ISDB-Tsb 64QAM,


Transmission DVB-S ARIB


ITU-R BO.1408


ITU-R BT.1306-1
ARIB STD-B41 ARIB STD-B29, ITU-R BS.1114 ITU-T J.83 Annex C, J.183
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
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
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.

ARIB Standards for Digital Terrestrial TV Broadcasting

For the details of structure of technical standard and relationship between each standards, see "Structure of Japan's digital broadcasting"



 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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