The directional structure of data transmission is "can be transmitted in both directions simultaneously". Full-duplex communication is also called two-way simultaneous communication, which allows data to be transmitted in two directions at the same time; full-duplex communication is a combination of two simplex communication methods, requiring both the sender and the receiver to have independent receiving and sending capabilities, that is, communication An information interaction method in which both parties can send and receive information at the same time.
The operating environment of this tutorial: Windows 7 system, Dell G3 computer.
Adopts full-duplex communication mode, and the directional structure of data transmission is "can be transmitted in two directions simultaneously".
Full-duplex communication is also called two-way simultaneous communication, that is, an information interaction method in which both parties to the communication can send and receive information at the same time.
Three communication methods of data
Data is usually transmitted between two stations (point-to-point), according to the direction of the data flow It can be divided into three transmission modes: simplex, half-duplex, and full-duplex.
1. Simplex communication (simplex)
Simplex communication only supports signal transmission in one direction (forward or Reverse), the signal transmission direction cannot be changed at any time.
In order to ensure the correct transmission of data signals, the receiving end must verify the received data. If there is an error in the verification, a signal requesting retransmission will be sent through the monitoring channel.
This method is suitable for data collection systems, such as meteorological data collection, centralized calculation of telephone bills, etc.
For example, the communication between the computer and the printer is simplex mode, because only the computer transmits data to the printer, and there is no data transmission in the opposite direction. There are also some communication channels, such as simplex wireless transmission.
2. Half-duplex communication (half-duplex)
Half-duplex communication allows signals to be transmitted in both directions, but only allows signals to be transmitted in both directions at a certain time. One-way transmission on a channel.
Therefore, half-duplex communication is actually a simplex communication with switchable direction.
This method is suitable for data communication systems such as inquiry, retrieval, and scientific computing;
Traditional walkie-talkies use half-duplex communication. Since walkie-talkies use the same frequency for transmission and reception, simultaneous transmission is not allowed. Therefore, after one party finishes speaking, he or she needs to try to inform the other party that the speech is over (for example, adding 'OVER' after finishing speaking), so that the other party knows that it can start speaking.
3. Full-duplex communication (full-duplex)
Full-duplex communication allows data to be transmitted in two directions at the same time, that is, there are two channels, so Simultaneous bidirectional transmission is allowed.
Full-duplex communication is a combination of two simplex communication methods, which requires both the sender and the receiver to have independent receiving and sending capabilities.
Full-duplex communication has high efficiency and simple control, but the cost is high.
The communication between computers is full-duplex. General telephones and mobile phones are also full-duplex systems, because you can hear the other party's voice when speaking.
Summary
Usually four-wire lines realize full-duplex data transmission, and two-wire lines realize simplex or half-duplex data transmission. When using the frequency division method, time compression method, and echo cancellation technology, the second-line line can also achieve full-duplex data transmission.
For more related knowledge, please visit theFAQcolumn!
The above is the detailed content of Using full-duplex communication, what is the directional structure of data transmission?. For more information, please follow other related articles on the PHP Chinese website!