What is a modem used for? Can anyone tell me a little bit more detail? Thank you!

Internet access. Modem (i.e., modem) is a device for signal conversion between the computer and the first line, consisting of two parts: the modulator and the demodulator, the modulator is the digital signal of the computer (such as files, etc.) is modulated into a device that can transmit the sound signal on the first line, and at the receiving end, the demodulator converts the sound signal into a digital signal that the computer can receive. Data communication between computers can be realized through a modem and a ** line.

At present, there are two main types of modems: built-in and external.

The built-in modem is actually a computer's expansion card, which can be used by plugging into an expansion slot in the computer, and it does not occupy the computer's serial port. Its connection is quite simple, insert the ** cable connector into the "line" socket on the card, and the other interface "phone" on the card is connected to the ** machine, when the modem is not used at all, the ** machine is not affected at all.

The external modem is a cassette device placed outside the computer, it needs to occupy a serial port of the computer, and it also needs to be connected to a separate power supply to work, there are several status indicators on the external modem panel, which can be convenient for you to monitor the communication status of the modem, and the external modem is easy to install and disassemble, easy to set up and maintain, and easy to carry. The connection of the external modem is also very convenient, and the connection of the phone and line is the same as that of the built-in modem. However, an external modem must use a serial cable to connect one of the serial ports of the computer to the serial port of the modem, and this serial cable is usually shipped with the external modem.

An important performance parameter of the modem is the transmission rate, which is currently available in both 56k modems on the market, and 56k modems have become the mainstream products in the market. However, due to the limitation of domestic communication lines, as well as the fact that there are too many users and too few international exports, it is difficult to achieve the above rates in normal use, so if the transmission rate is only a few kilobytes per second or even lower when you use it, you don't need to wonder if there is something wrong with your computer or modem.

Modems often look like small, black, elongated square boxes. Typically, they have two to four antennas, but not every modem includes an external antenna.

Modem is an abbreviation of "modulator" and "demodulator", affectionately called "cat" according to the homonym of modem. It is a device that converts a digital signal into an analog signal through modulation at the transmitter end and then converts the analog signal into a digital signal through demodulation at the receiving end.

How does the modem work:

The information in the computer is composed of digital signals composed of "0" and "1", while the transmission on the ** line can only be analog electrical signals. If no measures are taken to use analog channels to transmit digital signals, there will inevitably be great errors (distortions), so to transmit data on an ordinary network, it is necessary to convert the digital signal into the audio spectrum required by the original design of the network (i.e., 300Hz 3400Hz).

Modulation is to use baseband pulses to control a certain parameter of the carrier waveform to form a signal suitable for line transmission.

Demodulation means that when the modulated signal reaches the receiving end, the analog signal converted by the modulator removes the carrier and returns to the original baseband digital signal.

The use of a modem can also convert audio signals to higher frequency signals and higher frequency signals to audio signals. Therefore, another purpose of modulation is to facilitate the reuse of lines, so as to improve the utilization rate of lines.

It is a type of computer hardware that translates a computer's digital signals into analog signals, which in turn can be picked up by another modem and translated into a language that the computer can understand. This process completes the communication between the two computers.

Definition of modem name: It is the abbreviation of modulator and demodulator, also known as "cat".

Modulation: that is, the digital signal is converted into an analog signal transmitted on the first line.

Demodulation: Converting an analog signal into a digital signal.

Category: Built-in modem, Advantages: No need for additional power supply and cable, **Cheap. Cons: cumbersome installation.

External modem, advantages: convenient and flexible, easy to install. Disadvantages: Requires additional power and cables.

PCMCIA plug-in card type, advantages: small size, mobile office. Cons: Limitations, mainly used for laptops.

Rack-mounted modem is mainly used in the central computer room of Internet intranet, telecommunications bureau, campus network, financial institution and other networks.

A modem is a kind of computer hardware, which can translate the computer's digital signals into pulse signals that can be transmitted along the ordinary ** line, and these pulse signals can be received by another modem at the other end of the line, and translated into a language that the computer can understand. This simple process completes the communication between the two computers.

1. Modem (modulator demodulator) modem refers to a device that uses carrier-coded digital signals in the transmission to copper wires or dial-up connections.

2. The modem can communicate in both directions, because each modem contains a circuit for output data encoding and input data decoding.

The English word for modem is: modem. It is designed for the long-distance transmission of digital signals of data communication on analog channels with limited bandwidth, and it is generally composed of baseband processing, modulation and demodulation, signal amplification and filtering, equalization and other parts.

Modulation is the combination of digital signals and audio carriers to produce audio signals (analog signals) suitable for transmission on the first line, and demodulation is to recover digital signals from audio signals.

There are generally three types of modems: external, internal, and PC card types. It can be serial interface with the computer through ** cable or special network cable, external modem; The built-in modem plugs directly into the computer expansion slot; The PC card type is used by notebook computers and plugs directly into the standard PCMCIA slot.

The performance and rate of the modem are directly related to the speed of transmitting information after networking, and the rate of the modem is 56K, etc., and 56K is commonly used at present. CCITT proposes a standard for modems, the biggest features of which are:"Adaptive rate transfer"In the transmission process, according to the quality of the local user line, the product has the function of automatically adjusting the transmission rate, so that the network users with poor lines in the area can also enjoy the connection effect of high-speed transmission. The standard has 9600 128000bps signal rate, four-wire full-duplex communication mode, synchronization, single sideband modulation mode and 60 108kHz base group circuit. The standard has a signal rate of 56000bps, full-duplex communication, synchronization, data compression and error control technology.

Modem is a kind of computer hardware, is the modulator (modulator) and demodulator (demodulator) abbreviation, Chinese called modem (Hong Kong and Taiwan called modem), according to the homonym of modem, affectionately called "cat". It can translate the computer's digital signals into analog signals that can be transmitted along ordinary ** lines, and these analog signals can be received by another modem at the other end of the line and translated into a language that the computer can understand. This simple process completes the communication between the two computers.

To put it simply, a modem is what is usually called a "cat".

The cats on the notebook are all 56K,Connect RJ11 port,Connect to the ** line and dial the public username and password to access the Internet。

The network card is a network adapter, connected to RJ45 port, which is connected to broadband cat Internet access, and most of the home is 1MB.

Modem, is the abbreviation of modulator and demodulator, is a kind of computer hardware, which can translate the computer's digital signals into analog signals that can be transmitted along the ordinary ** line, and these analog signals can be received by another modem at the other end of the line, and translated into a language that the computer can understand. This simple process completes the communication between the two computers.

Take the current broadband service of China Unicom as an example, the network data is transmitted by the first line, in order not to interfere with the normal use of the network, the data on the network needs to be processed in a certain form, this process is called adjustment, and the data needs to go through a certain form of reverse processing after the user is on the user's side, that is, the data is taken out from the first line, this process is demodulation, and the adjustment demodulator is to perform this task.

Cats, ADSL and the like all use cats, and some directly specify the IP address, which can be used directly with the router.

It is the small box machine that you set up a network cable, Netcom or a telecommunications company sent you, commonly known as it; Cat.

Modem: A type of computer hardware.

Summary. A modem is a device used to convert digital signals into analog signals, usually for connections to broadband networks. Modems enable Internet connectivity by converting data from transmission** (e.g., wired, wireless, fiber, etc.) into digital signals that can be easily processed by a computer.

What is a modem.

A modem is a device used to convert digital signals into analog signals, usually for connections to broadband networks. Modems enable Internet connectivity by converting data from transmission** (e.g., wired, wireless, fiber, etc.) into digital signals that can be easily processed by a computer.

Fellow, I really didn't understand, I can be more specific.

Hello dear! A modem is a device used to convert digital signals into analog signals, usually for connections to broadband networks. Modems enable Internet connectivity by converting data from transmission** (e.g., wired, wireless, fiber, etc.) into digital signals that can be easily processed by a computer.

Summary. Introduction to Modem The modem is composed of two parts: the modulator and the demodulator, in which the modulator modulates the data information into a signal suitable for transmission channel transmission, and the demodulator demodulates the received signal into data information, and the modem belongs to the data circuit equipment DCE in the data communication equipment.

Introduction to Modulator Modulator Demodulator is composed of two parts: modulator and demodulator, in which the modulator modulates the data information into a signal suitable for transmission on the bridge transmission channel, and the demodulator demodulates and restores the received signal into data information, and the modem belongs to the data circuit in the data communication equipment and sets up the DCE.

The principle modulation of the modulator is to use the baseband pulse to control a certain parameter of the carrier waveform to form a signal suitable for line transmission, demodulation is when the modulated signal arrives at the receiving end, the analog signal converted by the modulator is removed from the carrier and restored to the original base orange band digital signal, and the modem can also convert the audio signal into a signal with a higher frequency touch rate and a signal with a higher frequency into an audio signal, so another purpose of modulation is to facilitate line reuse. in order to improve line utilization.