What is the function of modem

The function of modem is: 1. It can successfully convert the data signal sent by the signal source into an analog signal suitable for analog signal transmission; 2. When the data is being transmitted, the information will continue to be synchronized. Receiving end; 3. Use error correction protocol to detect whether there are errors in the received data packets. Once an error is found, it will try to regain the correct data packets or use algorithms to try to repair damaged data packets; 4. Use various encodings And modulation method to achieve channel multiplexing; 5. Direct connection.

#The operating environment of this article: Windows 7 system, Dell G3 computer.

Modem (English name Modem), commonly known as "cat", is a kind of computer hardware. It translates the computer's digital signals into analog signals that can be sent along ordinary telephone lines. These analog signals can then be received by another modem at the other end of the line and translated into a language that the computer can understand.

The function of modem is:

1. Signal conversion: It can successfully convert the data signal sent by the signal source into an analog signal suitable for analog signal transmission. At one end of the data, it will well complete the conversion to the opposite side of the source, and can also process noise and distorted waveforms.

2. Synchronous transmission: When data is being transmitted, the information will continue to be synchronized at the receiving end. It will extract the synchronized information sent and have synchronous phase locking, and then use the generated data to be in the same phase as the source. The carrier wave is used for sampling and information sink generation timing, so as to ensure that the information sink and information source are synchronized.

3. Data error correction: During network communication, data is sent in the form of data packets. Due to signal attenuation, poor line quality, or interference, data packets are often lost during transmission. or damaged. The modem uses an error correction protocol to detect whether there are errors in the received data packets. Once an error is found, it will try to regain the correct data packets or use algorithms to try to repair the damaged data packets.

4. Multiplexing: Hard drives can also take advantage of the orthogonality of slot numbers and use various coding and modulation methods to achieve channel multiplexing. At the same time, it can also compensate for the interference damage caused by harmful factors to the signal.

5. Direct connection: For example, many users can directly connect the modem's telephone line without acoustic coupling facilities. Or the user can send sequence information to the modem through some communication links, perfectly converting it into a response to the starting user. The number dialed by the modem can also be stored through the software access function of the PC keyboard, thus establishing communication with the host. System carrier signal connection.

If you want to know more about programming learning, please pay attention to the php training column!

The above is the detailed content of What is the function of modem. For more information, please follow other related articles on the PHP Chinese website!