Common Hardware glossary! Absolutely authoritative! (Go !) V. Modem Glossary

V. Modem Glossary
　　
At command (atcommands): a modem command language invented by Hayes, which is now a de facto standard and used by all modem manufacturers. The name of each command starts with the letter ". At is followed by letters and numbers to indicate specific functions. For example, "atdt" is a dialing command, other Commands include "initialize the modem", "control the speaker volume", "specify the number of calls for the modem to initiate a response", and "select the error correction format, the AT commands for modem of different grades are different. Please read the modem user manual carefully to use at commands correctly.
　　
Baud Rate (baudrate): the rate of analog line signals, also known as the modulation rate, measured by the number of vibrations per second in the waveform. If the data is not compressed, the baud rate is equal to the number of data transmitted per second. If the data is compressed, the number of data transmitted per second is usually greater than the modulation rate, in this way, the exchange between port and bit/s occasionally produces errors.
　　
DCE: the acronyms of "datacommunicationequipment (data communication device. DCE provides the function of establishing, maintaining, and terminating connections. A modem is a DCE.
　　
DTE: the acronyms of dataterminalequipment. DTE provides or receives data. A computer connected to a modem is a DTE.
　　
Modem: the abbreviation of modulator/demodulator. It is a device that converts a digital signal to a analog signal through modulation at the sending end, and then the analog signal to a digital signal through demodulation at the receiving end.
　　
Line rate (linerate): Also known as DTE rate. Unit: bit/s (BPS ). It refers to the data transmission rate on the telephone line (or leased line) connecting two modem. Common rates include 28800bps, 19200bps, 14400bps, 9600bps, and 2400bps.
　　
Port rate (portrate): Also known as DCE rate or maximum throughput. The transmission rate from the computer serial port to the modem. Today, almost all modem supports v.42bis and mnp5 compression standards at this rate (the compression ratio is), so this rate is generally much higher than the line rate.
　　
Leased Line/dial-up leased line: refers to two common passive (or active) wires. There is no dialing sound for dialing on the leased line, so dedicated hardware support is required. A dial-up line is a common telephone line, which is called by the telephone system. Common modems support dial-up lines rather than leased lines.
　　
RomoteSetup: After the local modem is connected to the remote modem, remote users can set the parameters of the local modem.
　　
He's compatibility: The AT command invented by Hayes has been widely used. Most other modem manufacturers use the AT command of Hayes to control the modem, which is compatible with heshi.
　　
Rate: the amount of data that the modem can transmit per second. In the modem industry, Kbps is generally used as the unit. 56 Kbps means that the number of binary data records that can be transferred per second is 56,000.
　　
Asynchronous: a communication method that provides simple device requirements. The standard communication interfaces provided by our PC are asynchronous.
　　
Synchronization: a communication method that has complex requirements on devices, but has high communication quality.
　　
Data bit: when data is transmitted through the modem online, each group of data transmitted must contain corresponding control data, including starting to send data and ending data, the most important part of this set of data is the data bit. In different communication environments, the number of data bit and second bit is generally specified.
　　
Traffic control: used to control the data flow between the modem and the computer, to prevent data loss caused by mismatch of the communication processing speed between the computer and the modem. Generally, there are hardware traffic control (RTS/CTS) and software traffic control (XON/XOFF.
　　
Terminal simulation: early computers used a host and many character terminals to work together. Today, PCs can imitate various terminals and connect to other computers through a modem. Computer software that imitates a terminal is called terminal simulation.
　　
Carrier: since only sound signals can be transmitted over a common telephone line, the modem must convert the digital signals on the computer into sound signals and transmit them over a telephone line. A carrier is actually a sound signal that carries digital information on a computer. The modem requires the carrier signal to communicate with each other. Therefore, only when the carrier signal is established between the two modem, the modem is called a connection.
　　
Terminal speed: the connection speed between the modem and the computer's communication port. This speed should be greater than the carrier speed.
　　
Carrier rate: the data transmission speed that the modem can achieve through telephone lines. The modem speed usually refers to the carrier rate.
　　
Automatic response: When a ringing signal is received, the modem automatically starts to answer the call from the other party and establishes a connection for computer communication.