How many ways to provide Internet service now?

With the rapid development of network technology, Internet access has become increasingly diversified. Below, introduce several ways to surf the Internet:

I. Modems There are many kinds of dial-up Internet modems, among which the cheapest and most common one is the audio modem using telephone lines as transmission media.

Second, the cable modem is also called the cable modem. With it, you can use cable TV network for data transmission and access the Internet at high speed through cable TV.

Three. ISDN access is an integrated services digital network. Users only need a communication line, an ISDN number and a terminal adapter with ISDN standard interface to realize high-speed and high-quality Internet access.

4.ADSL private line access is asymmetric digital subscriber private line access. So you don't have to pay the phone bill, and you can be online 24 hours a day. It is a special way of surfing the Internet and has no influence on answering and making calls.

At present, ADSL is the fastest, but the equipment cost is the highest; ISDN is faster, and the cost of access equipment is cheaper than ADSL; Cable modem has high hardware investment and cost, and is easy to install and use; Dial-up Internet access is simple, but the speed is slow.

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Service providers provide services.

1, dial-up Internet access

163 required equipment and access mode.

Required equipment

Have a 586 computer, related software, a modem and a telephone line, and then register an account in the local telecommunications department-your "network ID card" with valid documents that can prove your identity. After the account is opened, you will become an official "netizen" and start your "online life". Good luck!

What are the ways to visit CHINANET?

1, ordinary telephone dial-up network.

2, through ISDN, surfing the Internet through ISDN, you will feel like a dedicated line;

3. 163 dedicated telephone dial-up network. 163 dedicated telephone will save a lot of telephone charges for netizens. Dialing service number: 163.

4. For enterprise users, you can access the local area network to CHINANET through DDN special line, so that your enterprise can obtain information efficiently and release it to the world, and create unlimited business opportunities for your enterprise to go global!

Dial-up internet account opening fee

(Yuan) Basic fee, network usage fee and communication fee

China public computer internet

( 163) CHINFO

( 169)

Class A dial-up registration 100 0 3 yuan/hour 1.8 yuan/hour per minute.

0.02 yuan at a time

Class b business 0 50 yuan/month 2.5 yuan/hour 1.5 yuan/hour.

100 yuan/month 2 yuan/hour 1 yuan/hour.

network card

(stored value card) 0,000.05 yuan/minute 0.03 yuan/minute

Domestic roaming service 0 0 3 yuan/hour 3 yuan/hour

For dial-up registered users of Class A, Class B and network card services, the network usage fee will be halved from 0: 00 to 24: 00 (all day) on legal holidays and rest days, and halved from 23: 00 to 8:00 the next day on non-holidays. There is no preferential period for domestic roaming service.

2、ISDN

business introduction

"One-line communication" service, also known as narrowband integrated services digital network service (N-ISDN), is an integrated service integrating voice, data and image communication on the existing telephone network. "Single-wire communication" users can obtain integrated telecommunication services by using a pair of ordinary telephone lines: they can connect up to 8 different terminals and allow two terminals to communicate at the same time. It is more convenient and faster to surf the Internet through ISDN, and you can also make phone calls while surfing the Internet.

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Commercial advantage

(1) Compared with the traditional MODEM, ISDN is much faster than MODEM. The lowest speed of ISDN line is 64KB/S, and the highest speed can reach128 KB/s/s. ..

(2) All-digital line, short call setup time, good quality and high stability. Digital transmission of ISDN can effectively reduce noise and crosstalk, and make data communication more secure and reliable.

(3) The line efficiency is high. There are many machines in one line, and the two machines can communicate at the same time without interfering with each other.

(4) It can meet various business needs of users: computer networking, remote communication, image transmission, etc.

(5) Multimedia communication such as voice, video and data can be realized by using existing analog devices such as ordinary telephones, fax machines and computers, and high-speed Internet access can be realized by only adding an ISDN TA adapter.

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ISDN application

The line bandwidth of (1) 128K solves the problem of users' internet access speed.

(2) Similar to the speed of private line, the charge is equivalent to ordinary telephone.

(3) The best choice for data circuit backup in financial and securities industry.

(4) An ideal way to connect the office and school LAN to the Internet.

(5) Local telephone users have a new installation choice. At the same time, they can make phone calls or send and receive faxes while surfing the Internet and enjoy various telecommunication services.

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Commercial tariff

(1) initial installation fee: type A116 yuan, type B 12 16 yuan, modified 3 16 yuan.

(2) Monthly rental fee: 65438+ 0.5 times of fixed telephone.

(3) Call charges: It shall be implemented according to the standard of ordinary fixed telephone. When dual-channel (2B) is used, it shall be calculated as two telephones talking at the same time.

(4) new service usage fee: the same as ordinary fixed telephone.

3、ADSL

What is super one-line communication?

Super One Line is a broadband integrated services digital network (B-ISDN) with ATM broadband technology as its core, which provides users with high-speed and real-time data, voice, image and video. It adopts asymmetric digital signal transmission technology (ADSL), and makes full use of existing telephone lines to realize high-speed user access of uplink 1mbit/s and downlink 7M bit/s, which can simultaneously make telephone calls and transmit high-speed multimedia data on one telephone line.

Super one-stop service function

* Telemedicine broadband network provides high-definition medical information transmission, remote consultation and exchange, remote scheme formulation and collaborative surgical treatment, so that you can enjoy the most modern medical security without going far away.

* Conference TV real-time information exchange, clear video guarantee. The application of broadband interactive conference TV system makes the traditional large-scale conference no longer need centralized arrangement, which can not only ensure the effect, but also save expenses and improve efficiency.

* Long-distance teacher guidance, interactive teaching, broadband network to provide you with famous teachers from all over the world, provide lively multimedia teaching, take you into the online school, and realize your learning dream.

* The broadband network of the virtual commercial building will take you into a realistic three-dimensional supermarket, and show you all aspects of the goods through three-dimensional paintings, providing all kinds of information about the goods, so that you can buy whatever you want. Let you enjoy the real fun of online shopping without leaving home.

The high bandwidth of VOD ensures that users can play high-quality videos in real time, and the large-capacity DVD warehouse allows you to order movies that suit your taste at will. Enter the broadband multimedia information network, and you will have your own online cinema!

Three-dimensional entertainment high-speed real-time broadband network will provide users with a variety of online entertainment projects, such as three-dimensional chat rooms, simulated field trips, online real-time games and live TV broadcasts, adding luster to your life.

* * ADSL access to the Internet can reach the downlink rate of 6-8 Mbps, which is more than 200 times faster than ordinary MODEM dial-in. At the same time, it can realize collective * * * enjoyment in the company LAN.

How to use super one-wire communication?

It is very convenient and quick to install ADSL. To install ADSL on the existing telephone line, you only need to install ADSL communication terminals (ADSL modems, etc.). ) on the user side without making any changes to the existing line. Users can enjoy high-speed access service by dialing, and can also make normal calls while surfing the Internet. There are two ways to access broadband network through ADSL:

1.ADSL modem mode. Users can realize high-speed communication by installing a network card (10M Ethernet card or ATM 25M network card) on a microcomputer or installing a STB (set-top box) on a TV, connecting with an ADSL modem through a network card or a set-top box, and accessing a local host through a telephone line.

2.PC network card mode. Install the PC network card on the user's host, connect the telephone line through the PC network card and access the local host, thus entering the broadband network and realizing high-speed communication.

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The most critical factor of surfing the Internet is bandwidth. At present, most people still use the traditional 56K modem to connect telephone lines, so they often need patience, because the slow Internet access is the biggest headache for many users. In order to solve this problem in many ways, the following schemes have been put forward in the network in recent years. You can compare them to see which is better and which is worse.

1.ISDN scheme

The full name of ISDN is integrated services digital network, and the Chinese name is integrated services digital network. It is developed on the basis of integrated digital telephone network and can provide end-to-end digital connection. Ordinary analog telephone network becomes IDN after digital transmission and switching, but in IDN, analog transmission is still between user terminal and telephone exchange, and a modem is needed to transmit digital signals. ISDN digitizes all transmissions from one user terminal to another, including the user part, and handles all kinds of services in digital form, so that users can obtain excellent digital performance. However, the highest data transmission rate that ISDN can provide is 128kbps, which is still its best working frequency. Moreover, the ISDN used by users now is a narrow-band network, and the network has entered the bandwidth era, so the ISDN scheme still cannot meet the needs of Internet users.

2. Cable modem scheme

The cable modem is based on the original wired network. In the past, the cable TV industry only transmitted TV signals, but now it uses a set of closed cable transmission lines that have been established and transformed to realize Internet access and communication. Because CATV uses coaxial cable, the data capacity is quite large, and the download rate using coaxial cable can reach 30Mpbs. However, its problem is also obvious. Because the coaxial cable of cable TV is designed in one direction, only signals are allowed to be transmitted from cable TV station to users' homes, and signals are not allowed to be fed back from users' homes to cable TV stations. Internet networking is a two-way transmission mode, that is, users not only receive information on the Internet, but also transmit information to the Internet. It can be said that the solution of CATV is also to transform the basic line to make it reach the double transmission point of information. This may cost a lot of money for cable TV, and users must connect a high-speed cable modem to the computer to surf the Internet. In addition, Cable MODEM adopts HFC scheme and hierarchical digital structure, which simply connects several nodes together on digital nodes. So it is actually a rough bus network, which means that the bandwidth of users and neighbors is limited, so when a large number of people surf the Internet at the same time, the speed of cable TV will slow down. Due to the inherent unreliability of bus network, LAN technology began to replace bus structure with star structure a few years ago. Relevant information shows that, under the current circumstances, HFC scheme must take into account cable TV programs, and it is important that this cable TV solution is in the pilot stage.

3.DDN private line access scheme

DDN is the abbreviation of "Digital Data Network", and its Chinese name is Digital Data Network. It is a digital transmission network that mainly provides digital channels and data signal transmission with semi-permanent connection circuits. It will provide users with a rate of 64Kbps-2Mbps. However, its expensive access fee and monthly fee make ordinary users flinch. It can be said that DDN is more suitable for enterprise users, and it is an ideal choice to build a private communication network by using the services provided by DDN, but its high cost is unacceptable to ordinary supporters.

4.ADSL scheme

ADSL scheme does not need to transform the telephone signal transmission line, it only requires users to have a special modem, that is, ADSL modem. It is connected to the user's computer, and the other end is connected to the ADSL network of the telecommunications department. Ordinary telephone lines are still connected between users and telecommunications departments. Generally speaking, the transmission speed of ADSL scheme is about 50 times that of ISDN scheme, and there is no need to transform the broadband network of the line, so ADSL is a feasible scheme to accelerate Internet access at present.

Because of the high access cost of DDN, it is definitely not suitable for ordinary home users. At present, the application scope of cable modem is very small. So far, only a few communities in Shanghai are conducting pilot projects, and it is estimated that it will take a long time to launch. From the above introduction, we can see that ADSL scheme has very obvious advantages and will undoubtedly be a good choice for future families. Then let's introduce ADSL in detail:

First, the definition of ADSL

ADSL (Asymmetric Digital Subscriber Line), also known as Asymmetric Digital Subscriber Line, is a kind of xDSL. XDSL is the general name of DSL, which means digital subscriber line. XDSL is a combination of transmission technologies using copper telephone lines as transmission media, where "X" stands for different kinds of digital subscriber line technologies, including ADSL, HDSL, VDSL, SDSL and so on. The differences of various digital subscriber line technologies are mainly manifested in the transmission rate and distance of signals, as well as the differences of symmetry and asymmetry.

ADSL uses ordinary telephone lines as the transmission medium. Although the traditional modem also transmits by telephone line, it only uses the low frequency band of 0-4 kHz, and the telephone line theoretically has a bandwidth close to 2MHz. ADSL can only provide such a high speed by using high frequency after 26KHz. The specific workflow is as follows: the signal encoded by ADSL modem is transmitted to the telephone office through telephone line, and then passes through a signal identification/separator. If it is a voice signal, it is transmitted to a switch, and if it is a digital signal, it is connected to the Internet.

2. Functions and standards of 2.ADSL

ADSL is designed for two purposes: high-speed data communication and interactive video. The function of high-speed data communication can bring convenience to Internet access, the management of company remote computers or the application of private networks. Interactive video, including video on demand, movies, games and so on, is realized on high-speed network. Undoubtedly, the wide application of interactive video will definitely bring more colors to our poor life.

There are three common standards for ADSL: QAM, CAP and DMT. Among them, DMT standard has been adopted by the national standard formulated by ANSI standardization group. CAP standard is developed on the basis of QAM standard, which can be said to be a variant of QAM standard. Although CAP is not a standard, it is made by AT&: the invention of Tparadyne has been widely used in communication. In addition to the above-mentioned standard dispute, the G.Lite standard, which has been talked about a lot recently, has also been favored by the industry recently. It is precisely because of the disunity of standards for a long time that ADSL has not been popularized. DMT and G.Lite have their own advantages and are suitable for different fields. DMT is a full-rate ADSL standard, which supports 8Mbps high-speed downlink and 1.5Mbps uplink. However, DMT requires users to install POTS separators, which is very complicated. For example, Ericsson ADSL modem supports DMT standard. Although the rate of G.Lite standard is low, that is, the downlink rate is 1.5Mbps and the uplink rate is 5 12Kbps, users can buy it directly from the store just like using an ordinary modem, and then simply install it themselves. In the application field, DMT is suitable for small or home offices, while G.Lite is used for ordinary home users.

3. The rate of 3.ADSL:

After adopting ADSL scheme, theoretically speaking, ADSL supports upload rate of 640Kbps- 1Mbps, download rate of 1Mbps-8Mbps, and effective transmission distance of 3-5 kilometers. But in practical application, it can also dynamically adjust the access speed of users according to the quality of twisted-pair copper wire and the transmission distance. The actual download rate we can enjoy is determined by various factors, such as the different modem models used, the distance from the user to the communication center, the cable size, interference, etc., ranging from 10 kbps to 640 kbps. The most direct benefit brought to users by the improvement of transmission rate is to save a lot of time and money.

In addition, ADSL uses advanced algorithms, uses its unique modem hardware to connect all endpoints of existing twisted-pair connections, and creates a pipeline with three channels. The pipeline has a downlink channel to users, a medium-speed duplex channel and a POTS channel. POTS channel is used to make voice communication work normally even if ADSL connection fails. Both high speed and medium speed channels can be multiplexed to create multiple low speed channels. In the practical use of high-speed and medium-speed channels, users can make voice calls or send faxes while downloading and sending data, which will not affect the call quality or reduce the speed of downloading Internet content, that is, ADSL uses frequencies other than telephone voice transmission to transmit data.

4.ADSL installation method

When installing ADSL, you don't need to change the telephone line, just load a multiplexing device on the original telephone line, and users don't need to add another telephone line. When using ADSL, users must use a special modem called endpoint. Immediately after this modem, the user's computer needs to install an ordinary network card to connect to this modem, so this modem is like being installed on the network side, and the built-in card does not need to be connected to the network card.

In addition, many ADSL modems have combined these two functions into an internal multi-function card. However, many traditional modem manufacturers, such as Hayes, 3Com, GlobalBilage, Parkin, etc. The terminal modem is produced.

Verb (abbreviation of verb) Disadvantages of ADSL

Of course, ADSL is not perfect, and it also has its own shortcomings. Firstly, the existing ADSL modems are expensive. Secondly, establishing a reasonable charging system is the most important problem that ADSL faces. Then there is ADSL, and the performance varies greatly for different quality lines. For example, on a poor quality line, its downlink rate may only reach 1Mbps.

Ok, ADSL is over. It should be noted that the opening scope of ADSL is still very small, basically limited to several big cities such as Shanghai and Shenzhen. It seems that it will take some time for everyone to enjoy the fast internet experience of ADSL.

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