Analysis on the Development of IPTV Terminals and Widespread Application of Set-top Box Technology

The development of broadband networks and access technologies has expanded the application scope of broadband services. TV programs that are familiar to the public can not only be transmitted to TV via Cable, but also can be watched on PC, mobile phone or set-top box + TV using broadband IP network. This is the power of IPTV. The emergence of the IPTV concept has caused strong controversy in the two major industries of television and telecommunications. The television industry believes that IPTV is a supplement to digital television and should be implemented with IP over DVB technology, while the telecommunications industry believes that IPTV is a value-added service on the IP network and is implemented using TV over IP. Due to the different technologies used by various industries to implement IPTV, the user terminals that present the services are also very different. Digital television transmits television signals via Cable and satellite, and the user terminal is STB-C + TV or STB-S + TV; there are three main types of IPTV terminals for telecommunications users: personal computer + software player, TV + set-top box, and multimedia mobile phone for mobile streaming media platform. This article mainly introduces IPTV terminals and set-top box technologies used on IP networks.

1. IPTV terminal types

1. PC-based terminal system

The PC-based terminal system is an application form of Internet video, using network streaming technology to transmit a certain format of data streams. Users can use the corresponding player on the computer to decompress the compressed audio and video streaming files and play them. This form of terminal hardware is relatively simple. It only requires a PC with an Ethernet card to install the corresponding player application software to play audio and video programs and browse the Internet. Currently, the most commonly used player software includes Microsoft's Windows Media Player, Apple's QuickTime and RealNetworks' Real Player.

The advantages of the PC-based terminal system are simplicity, low investment, and convenient Internet access. The disadvantages are that each player software is limited to the manufacturer's proprietary file format and has poor versatility. The second is that watching TV programs on a PC monitor is smaller than watching on a TV and is less comfortable. The third is that people who cannot use a computer cannot enjoy this service at all.

Therefore, in view of the above analysis, the use of PC as an IPTV terminal system can only be used temporarily or in places where it is not suitable to place a TV, and is not suitable for large-scale promotion.

2. STB-based terminal system

The terminal system based on STB combines the functions of PC and TV, and has both the processing power of PC and the viewing effect of TV. At the same time, STB is very likely to appear as a home network/media center in the next generation of home network. Therefore, IPTV terminals are more optimistic about the TV + set-top box mode, which will become the mainstream of IPTV service terminals.

The STB-based terminal system uses a TV as a display and utilizes a dedicated IP-STB to receive and decompress network audio and video media data, converting it into a TV signal format for transmission to the TV for playback.

The functions that STB should have as a user terminal device include the following:

Supports video on demand, multicast, Internet browsing, short messages, video services and online games;

Supports multiple broadband access methods such as LAN, xDSL or WLAN, which are widely used at present, supports TCP/UDP/IP protocol suite, completes network transmission of interoperable information, and receives and processes IP data and video streaming data;

Supports multimedia code stream decoding, TV screen display and digital rights management;

Supports content caching, interaction control, access authentication, and business and network management functions.

3. Mobile terminal system

When it comes to mobile terminal systems for IPTV, people naturally think of 3G mobile phones, which can process multimedia such as images, music, and video streams, and use the combination of wireless communication networks and the Internet to provide a variety of media services such as Internet TV, video calls, web browsing, video conferencing, and e-commerce.

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There are still many problems to be solved in the application of IPTV mobile terminals. First of all, in terms of viewing effect, no matter what technology is used to play the image, its speed will be restricted by the network speed, and it is difficult to achieve the smooth effect of real-time transmission like TV. Although the effect of watching online videos on mobile phones is not bad at present, this is because mobile video services are still limited to a small number of high-end users. With the development and popularization of IPTV services and the increase in the number of users, network bandwidth and mobile phone processing capabilities may become a bottleneck. In addition, the current mobile phone power supply technology cannot match the powerful functions of IPTV mobile terminals. The standby time of mobile phones is too short, and the IPTV service has a minimum of 90 minutes of a movie, which consumes a lot of power. It is okay to watch a short program, but if you want to watch a full movie, you need to constantly replace the battery, which is undoubtedly a big obstacle for IPTV services.

4. STB+TV will become the mainstream terminal for IPTV services

IPTV services can be implemented by various types of terminals, but the most practical and acceptable combination for consumers should be a set-top box + TV. First of all, this method maintains the user's leisure habits. From the perspective of human biology, the most comfortable viewing posture is to lean back 30 degrees, and the posture for operating a computer is to lean forward 30 degrees. Traditional Internet video users use PCs as display terminals and need to lean forward when operating a computer. Therefore, long-term computer operation will make them very tired and prone to diseases such as cervical spondylosis and periarthritis of the shoulder. Secondly, the STB + TV method can not only keep TV programs, but also move Internet content from the study to the living room, so that people who cannot operate a computer can also surf the Internet, send and receive emails, and chat on the Internet. It will expand broadband users from Internet users to non-Internet users, and extend the broadband entertainment market from more than 22 million broadband users and more than 87 million Internet users to more than one billion TV viewers.

In short, whether the IPTV terminal uses STB+TV or PC, it should have the following functions: communication interface, analog signal output, peripheral control capability, video decoding and embedded real-time operating system. Through the terminal device, users can make service requests, receive video/audio data and network services.

2. Set-top Box Overview

1. What is a set-top box?

As the name implies, a set-top box (STB) is a box placed on a TV set, which originated from digital TV. It is a conversion device that converts digital TV signals into analog signals. In digital TV applications, there are three types of digital TV set-top boxes, mainly based on different transmission networks: digital TV set-top boxes STB-C for cable TV networks, digital TV set-top boxes STB-S for satellite TV networks, and digital TV set-top boxes STB-T for terrestrial broadcasting networks, which meet the corresponding standards of digital TV DVB-C, DVB-S and DVB-T respectively. The emergence of set-top boxes based on Internet Protocol (IP) is a recent thing. With the development of IPTV, this product has gained great development momentum. Because IP set-top boxes can not only provide the same functions as most cable or satellite TV set-top boxes, but also use the current low-cost Internet and IP-based network facilities. In addition, based on the two-way IP network, it can also instinctively support a series of applications and interactive services.

2. Development history of set-top boxes

The set-top box STB (Set-Top-Box) originated in the early 1990s and was an important means of collecting cable TV fees in Europe and the United States.

Cable TV operators install a key box in front of each user's TV. Only users who have paid can decrypt the TV signal and watch TV normally. This is the original set-top box.

In the mid-1990s, the Internet was developing rapidly and gaining popularity around the world. People began to think about using their TVs to access the Internet, and so they began to research set-top boxes that could access the Internet. At the time, computer and network equipment manufacturers hoped that set-top boxes that could access the Internet could become new home appliances. However, due to the immaturity of various technologies, they ultimately failed to take off.

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At the end of the 20th century, after the trial broadcast of digital television (DTV) and high-definition digital television (HDTV) in Europe and the United States, the set-top box boom was once again launched. The main function of the set-top box at this time is to convert digital TV signals into analog signals to ensure that ordinary analog TV sets can watch digital TV or digital high-definition TV.

The emergence of IPTV has led to further development of set-top boxes. Set-top boxes are not only used for digital television, but also serve as a bridge between IP networks and televisions, allowing the rich and colorful program content on broadband networks to be displayed on televisions through set-top boxes, bringing a new digital life experience to ordinary TV viewers.

3. Functions of IP set-top box

The basic function of an IP set-top box is to receive digital TV programs. It also has all broadcast, on-demand and interactive multimedia application functions, and also includes the following functions.

(1) Electronic Program Guide (EPG): EPG provides users with a user-friendly, easy-to-use, and fast way to access programs. Through the EPG function, users can see the TV programs that will be broadcast on all channels in the near future and the index of program content that users can choose to watch on demand, and actively search for programs on demand.

(2) Interactive applications: Provide users with video on demand, multicast, and interactive games. Through the application of interactive functions, people can fast forward, rewind, and pause when on demand, just like operating a home DVD; when multicasting, they can quickly switch TV channels. Through the application of interactive functions, people can also play interactive games.

(3) Online software upgrade: The set-top box middleware plug-in can provide set-top box capability detection, online installation and update of set-top box application software. The set-top box can identify the version number of the software, receive the software when the version is different, and update the software stored in the memory.

(4) Internet browsing and email: Users can access the Internet and send emails through the built-in Internet browser of the set-top box.

4. Types of IP set-top boxes

At present, there are basically two types of set-top boxes used for IPTV services: ordinary and enhanced. The basic set-top box has service capabilities such as on-demand function, broadcasting function, EPG browsing, WEB browsing and small games; the enhanced set-top box adds personal video storage (PVR), online games, video communication, FLASH and other service capabilities on the basis of the basic type. The IPTV set-top box can access the broadband network by FTTB+LAN access, xDSL access, WLAN access and other broadband access methods. There are generally three ways to implement the IPTV set-top box hardware platform: STB based on dedicated chips, STB based on digital signal processors DSP, and STB based on central processing units CPU.

With the emergence of IPTV services, many set-top box manufacturers and telecommunication equipment manufacturers are actively researching set-top boxes for IPTV, but most of the products currently developed are only applicable to their own IPTV service systems. Such set-top boxes bound to the system have poor versatility and cannot communicate with other IPTV systems at all. As a result, service operators will be passive in equipment selection and cost control, which will hinder the development of IPTV in the long run. The solution to this problem is to formulate IPTV set-top box technical standards as soon as possible and formulate unified specifications in terms of service functions, performance and security.