Tag: Digital TV Mobile TV DMB
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1. What is digital TV?
Today, digital TV is one of the most talked about topics. Because digital TV is a new thing, some related reports and philosophical concepts appear in the introduction of articles, such as "digital TV", "all-digital TV", "all-media TV", "multimedia TV", etc., causing confusion to the public. Overwhelmed. In fact, the meaning of "digital television" does not refer to the television set in our general family, but to the television system or television equipment that uses digital signals in the processing, transmission, transmission and reception of television signals. The specific transmission process is: the image and sound signals sent by the TV station are digitally compressed and digitally modulated to form a digital television signal, which is transmitted via satellite, terrestrial radio or cable, etc., after being received by the digital television, through digital solution. Harmonic digital video and audio decoding processing restores the original image and accompanying sound. Because the whole process is processed by digital technology, the signal loss is small and the receiving effect is good.
2. Use of digital television
In digital TV, the two-way information transmission technology is adopted, which increases the interactive ability and gives the TV many new functions, so that people can obtain various network services according to their own needs, including video on demand, online shopping, distance learning, telemedicine. Waiting for new business, making TV a veritable information appliance.
The most important service provided by digital TV is Video on Demand (VOD). VOD is a brand new way of TV viewing. Unlike traditional TV, users can only passively watch programs broadcast on TV stations. It provides greater freedom, more choice, and more interactive capabilities. The user's needs, look at the user's point, effectively improve the program's participation, interactivity, and pertinence. Therefore, it can be foreseen that the future development direction of television is to develop in the direction of the on-demand mode. Digital TV also provides other services, including data transmission, graphic broadcasting, and Internet services. Users can use TV real stock trading, information inquiry, web surfing, etc., to make the TV a new use, expand the function of the TV, and turn the TV from a closed window into a communication window.
The basic principles of digital television
After digitizing the video and audio signals of the TV, the amount of data is very large, which is very unfavorable for transmission, so data compression technology becomes the key. There are two ways to implement data compression: one is to compress in the source encoding process, the IEEE MPEG expert group has developed the ISO/IEC13818 (MPEG-2) international standard, and MPEG-2 uses different layers and levels. It can meet the requirements of different quality from home quality to broadcast quality and high definition TV to be broadcast. It has a wide range of applications. It supports standard resolution 16:9 widescreen and high definition TV. This standard is adopted for DVD-to-satellite and radio and television microwave transmissions that enter the home. The second is to improve channel coding, develop new digital modulation techniques, and increase the data transmission rate per unit bandwidth. For example, in the European DVB digital television system, the digital satellite television system (DVB-S) uses quadrature phase shift keying modulation (OPSK); the digital cable television system (DVB-C) uses quadrature amplitude modulation (QAM); The terrestrial open circuit television system (DVB-T) uses more complex coded Orthogonal Frequency Division Multiplexing (COFDM) modulation.
The characteristics of digital TV
Compared with analog TV, digital TV has several advantages:
1, the viewing effect is good, the image clarity is high, the audio quality is high, to meet the needs of people's senses.
2. Strong anti-interference ability. Digital TV is not easily interfered by the boundaries, avoiding the effects of stringing, crosstalk, and noise.
3. High transmission efficiency. 8-10 sets of standard definition digital TV programs can be transmitted using the analog channels in the cable television network.
4. Compatible with existing analog TV sets. Digital TV programs can be viewed by installing a digital set-top box in front of a regular TV set.
5. Provide a brand new business. With the two-way network, digital TV can not only realize user-on-demand programs, freely select various information on the Internet, but also provide various data value-added services.
V. Introduction to Digital Mobile TV
Digital mobile TV is an internationally recognized emerging media and is known as the "Fifth Media." It is supported by digital technology and plays and receives TV programs through wireless digital signal transmission and terrestrial digital reception. Its biggest feature is to keep the TV signal stable and clear on the moving state, the speed of 120 kilometers per hour, so that the viewer can easily watch the TV program in the mobile state.
Mobile TV, like broadcast, uses wireless signal transmission and terrestrial reception. As long as there is a digital TV (receiving) machine, just like having a radio, you can receive signals on the move wherever the field strength is.
Digital mobile TV features
1. Digitalization of technology: The digital technology adopted by digital mobile TV has high technology content and strong technological innovation. The program receives clear, the picture and sound effects are good when the vehicle speed is 120 kilometers per hour.
2. Instant communication: The emergence of digital mobile TV allows mobile people to watch TV anytime and anywhere, and obtain more updated information, which greatly satisfies the demand for information in fast-paced society and enriches the cultural life of citizens. Passengers can eliminate troubles by watching clear and interesting TV shows even when they are in traffic jams.
3. Monopolistic communication: In traditional TV communication, the audience has relative initiative - he can choose when to watch, see what, and change channels at any time, which is not ideal for advertising. The audience in the mobile TV communication environment is in a relatively passive position, and has the necessary visuality for a certain pre-existing content of communication - unless you close your eyes and do not look at it. The monopolistic spread of mobile TV deprives viewers of the "remote control" and the right to change channels at any time, which is conducive to cultivating the consciousness of the public to watch the same program in groups. This is for some preset content (such as advertising). In terms of communication, the effect is better.
4. Accessibility of content: The digital mobile TV system is jointly invested and constructed by the media company and the transportation system. The audience does not need to increase personal investment and consumption costs, and only pays “attention resourcesâ€, which is easy for the audience to accept. From this point of view, the popularity of digital mobile TV is a business that is both profitable and socially philanthropic.
5. Maximizing the use of information: How to make existing information serve the most people and generate the greatest economic and social benefits has always been a concern and consideration of media people. The use of information and information by traditional TV media is far from exerting its due value. With the development of mobile TV, the investment builder can be a traditional TV media. He can make full use of his existing manpower and program resources to create greater benefits, which will save a lot of cost; on the other hand, it can also set up a special The mobile TV channel integrates the news and information resources of each station, and serves the broader audience through the mobile TV system, maximizing the use of information and maximizing profit generation.
Market prospects
The first application of digital mobile TV was in Singapore, where eight digital TV transmission stations were built. In February 2001, mobile TV equipment was installed on 1,500 buses to provide mobile TV services to 1.5 million passengers.
In-Stat/MDR, a high-tech market research company, pointed out in a report that the global mobile TV market will usher in a period of rapid growth from 2004 to 2008. In 2006, a large number of terminals supporting mobile TV will be available. In 2009, mobile TV services will create a value of $5.4 billion per year.
In mainland China, more than ten cities including Shanghai, Beijing, Guangzhou, Wuhan, Changchun and Nanjing have begun to broadcast mobile TV on buses. Shanghai Wenguang Group took the lead in launching mobile TV business in China, and has completed the installation of display screens on more than 4,000 buses; Beijing Beiguang Media Mobile TV Company piloted mobile TV programs in April this year, and the number of TV installations for buses at the end of the year is planned to reach 4000 vehicles; Hubei Province will set up a special digital mobile TV station to launch mobile TV and related services with public transportation vehicles as the main carrier in Wuhan.
The target customer groups of digital mobile TV are firstly passengers on subways and buses; secondly taxis, official cars and private cars; third are trains, coaches, planes and ships.
1) Great advertising potential: Digital mobile TV digs a large audience from the “blind zone†of traditional TV, which is the root of advertising potential. The capacity of the public transport system in major cities across the country is huge. In 2003, Beijing had 776 bus lines, 9019 buses of various types, more than 5,000 vehicles within the Fourth Ring Road, and an annual passenger volume of 4.3 billion passengers; Beijing Metro The daily traffic is also as high as 1.3 million. Shanghai has more than 900 bus lines, more than 9,000 buses, and two subway lines... 2000-5000 vehicles in each large and medium-sized city, and two digital mobile TVs installed in each vehicle. Each monthly income is 1000. Far calculation, a city's mobile TV advertising revenue of less than 70 million yuan a year, and similar cities in the country no less than 100, if fully utilized, its considerable profit will reach 7 billion, equivalent to CCTV 2003 full year advertising The amount of income is enough to make all the capitals red. National trains carry 1.3 billion passengers per year (2003 data), and with the city's subway, taxis and private cars, its commercial value is more than "massive", and the prospects for digital mobile TV are extremely optimistic.
2) Industry chain effect: The digital mobile TV industry chain can be divided into four links, equipment manufacturers (transmitting, receiving, display equipment), content providers, channel operators and content consumers. Digital mobile TV has opened up a new economic growth point, not only because he has brought the equipment manufacturers and the media industry to life, but also because it will drive the growth of the corresponding industries. Haier, Konka, Skyworth, TCL, Changhong, Xoceco and other major TV giants have been keeping a close eye on the enticing "cake" of digital TV. 8000 Haier V6 digital LCD TVs have won the bid for the first batch of terrestrial wireless digital mobile TV projects in Beijing, and they were installed and put into use in Beijing in April. It is reported that. The “Zhongshi Guangyuan Media Network†with CCTV background has begun to install and open mobile TV channels on 34 train lines across the country. More than 4 15-inch LCD TVs are installed in each car, which is another fierce market.
3) Combined with mobile communication and computer: At present, Nokia and other mobile phone manufacturers are developing new products with mobile TV reception. Samsung Electronics has developed the world's first core for terrestrial digital multimedia television broadcasting (DMB). The chip combines a multimedia chip that processes video with a chip that can watch broadcast television programs. These products do not rely on mobile communication networks. Digital mobile TV can also be viewed on mobile phones before 3G is launched. Once the mobile digital TV technology matures, the mobile phone market will also set off a “mobile TV†boom, which will also drive the development of related mobile communication terminal (mobile phone) manufacturers. In the future, you can also watch TV with handheld devices. For example, you can use your mobile phone to watch morning news, watch sports on your laptop, or use your handheld to watch those TV shows we like.
A. What is digital TV?
Digital television refers to television systems or television equipment that use digital signals in the processing, transmission, transmission and reception of television signals. The specific transmission process is: the image and sound signals sent by the TV station are digitally compressed and digitally modulated to form a digital television signal, which is transmitted via satellite, terrestrial radio or cable, etc., after being received by the digital television, through digital solution. Harmonic digital video and audio decoding processing restores the original image and accompanying sound.
B. What is mobile TVmobile TV?
Mobile TV is commonly known as mobile TV. Supported by digital technology, it broadcasts and receives TV programs through terrestrial or satellite TV signal broadcasting and ground equipment reception. Currently, TV signals are received through terminal devices such as mobile phones, multimedia players, vehicles, and USB receivers. Its biggest feature is to keep the TV signal stable and clear on the moving vehicle.
C. What is CMMB?
CMMB is the abbreviation of China Mobile Multimedia Broadcasting. It is the first self-developed system for a variety of mobile terminals. It uses S-band satellite signals to achieve "world-wide" integrated coverage, national roaming, support 25 sets of TV programs and 30 sets of broadcast programs, and transmission technology using STiMi technology.
D. What is mobile TV?
The mobile TV service is a business that uses a smartphone with an operating system and video functions to watch TV. A mobile TV terminal refers to a mobile phone with mobile TV reception capability.
E. What is DMB-TH?
DMB-TH is a digital TV terrestrial transmission standard for China's independent intellectual property rights. The core of DMB-TH technology uses mQAM/QPSK time domain synchronous orthogonal frequency division multiplexing (TDS-OFDM) modulation technology, using the latest LDPC forward error correction coding technology, which can be applied to fixed and mobile digital TV reception. system.
F. What is DVB-H?
DVB-H is a transmission standard for providing multimedia services to handheld terminals over terrestrial digital broadcasting networks.
G. What is DMB?
"DMB is the acronym for Digital Multimedia Broadcasting. It is a new concept multimedia mobile broadcasting service that combines communication and broadcasting. In addition to supporting traditional audio broadcasting, this technology will also be able to pass MGEG-4 H.264 and MPEG-2. AAC+ and other methods to transmit a variety of multimedia information such as traffic information and news to the terminal, providing high-quality sound quality and diverse data services. It is especially suitable for mobile receiving environments and can better cope with mobile receiving environments. Multipath interference problems with degraded signal quality."
H. What is DAB?
DAB is short for Digital Audio Broadcasting, which is digital audio broadcasting. It is the third generation broadcast after AM and FM traditional analog broadcasting. In addition to all the advantages of digital signal transmission anti-noise, anti-interference, anti-wave propagation fading, etc., it can also provide CD stereo sound quality and digital information services. And within a certain range is not affected by multipath interference to ensure fixed and mobile reception quality. At present, the development of DAB systems in the world can be roughly divided into European regulations Eureka-147, American IBOC (In-Band On-Channel) and French DRM (Digital Radio Mondiale).
I. What is DVB-T?
DVB, the abbreviation for Digital Video Broadcasting, is a series of internationally recognized digital television public standards maintained by the DVB project. DVB-T (Digital Video Broadcasting-Terrestrial) is a terrestrial digital television broadcast that uses VHF and UHF carriers and uses COFDM modulation.
J. What is MPEG?
The full name of MPEG is the Moving Picture Experts Group, an organization that specializes in the development of international standards in the field of multimedia. The MPEG compression standard is designed for moving images, which can achieve compression between frames, a high compression ratio, a uniform format, and good compatibility. MPEG series standards include MPEG-1, MPEG-2, MPEG-4, MPEG-7, etc.
K. What is MPEG-2?
The MPEG organization introduced the MPEG-2 compression standard in 1994 to enable the possibility of interoperability between video/audio services and applications. The MPEG-2 standard is a detailed specification for the compression scheme and system layer of SD digital TV and HDTV in various applications. The code rate is from 3 megabits to 100 megabits per second. The standard formal specification is ISO/ In IEC13818. MPEG-2 is particularly suitable for the encoding and transmission of broadcast-grade digital televisions and is recognized as the encoding standard for SDTV and HDTV.
L. What is H.264?
H.264 is a new digital video coding standard developed by ITU-T's VCEG (Video Coding Experts Group) and ISO/IEC MPEG (Moving Video Coding Experts Group) Joint Video Team (JVT). It is both ITU-T H.264 (MPEG-4 Part 10) and ISO/IEC Part 10 of MPEG-4.
M.DTV digital TV terminology:
STB - Set-top Box set-top box
IRD - Integrated Receive Decoder Integrated Receiver Decoder
STM——Synchronous Transport Module Synchronous Transmission Module
GE - Giga Ethernet Gigabit Ethernet
ATM - Asynchronous Transfer Mode Asynchronous Transfer Mode
DAB - Digital Audio Broadcast Digital Audio Broadcasting
EPG - Electronic Program Guide
TS - Transport Stream transport stream
ASI - Actuator Sensor Interface adjusts sensor interface
MPEG - Motion Picture Exports Group Motion Picture Output Expert Group
PSIP - Program System Information Protocol
SI - Service Information Service Information
iTV - interactive TV interactive TV
STM——Synchronous Transfer Mode
XML - Extensible Markup Language Extensible Markup Language
IP-TV - Internet Protocol TV
DSLAM - Digital Subscriber Line Access Multiplexer Digital Subscriber Line Data Multiplexer
DSL - Digital Subscriber Line Digital Subscriber Line
DMB - Digital Media Broadcasting Digital Media Broadcasting
DAB - Digital Audio Broadcasting Digital Audio Broadcasting
DMB-H——DMB-Handl handheld DMB
DMB-T - DMB-Terrestrial Digital Terrestrial DMB
MUSICAM - Masked Universal Subband Integrated Coding and Multiplexing (MP2)
VDSL - Video Digital Subscriber Loop Video Digital Communication Network
ADSL - Asymmetrical Digital Subscriber Loop Asymmetric Digital Subscriber Line
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