Show Data Transmission mode defines the direction of the flow of information between two communication devices. It is also called Data Communication or Directional Mode. It specifies the direction of the flow of information from one place to another in a computer network. In the Open System Interconnection(OSI) Layer Model, the Physical Layer is dedicated to data transmission in the network. It mainly decides the direction of data in which the data needs to travel to reach the receiver system or node. So, in this blog, we will learn about different data transmission modes based on the direction of exchange, synchronization between the transmitter and receiver, and the number of bits sent simultaneously in a computer network. The data transmission modes can be characterized in the following three types based on the direction of exchange of information:
The data transmission modes can be characterized in the following two types based on the synchronization between the transmitter and the receiver:
The data transmission modes can be characterized in the following two types based on the number of bits sent simultaneously in the network:
Now, let us study these various data transmission modes in the computer network one by one. According to the Direction of Exchange of Information: 1. SimplexSimplex is the data transmission mode in which the data can flow only in one direction, i.e., the communication is unidirectional. In this mode, a sender can only send data but can not receive it. Similarly, a receiver can only receive data but can not send it. This transmission mode is not so popular because we cannot perform two-way communication between the sender and receiver in this mode. It is mainly used in the business field as in sales that do not require any corresponding reply. It is similar to a one-way street. For Example, Radio and TV transmission, keyboard, mouse, etc. Following are the advantages of using a Simplex transmission mode:
Following are the disadvantages of using a Simplex transmission mode:
2. Half-DuplexHalf-Duplex is the data transmission mode in which the data can flow in both directions but in one direction at a time. It is also referred to as Semi-Duplex. In other words, each station can both transmit and receive the data but not at the same time. When one device is sending the other can only receive and vice-versa. In this type of transmission mode, the entire capacity of the channel can be utilized for each direction. Transmission lines can carry data in both directions, but the data can be sent only in one direction at a time. This type of data transmission mode can be used in cases where there is no need for communication in both directions at the same time. It can be used for error detection when the sender does not send or the receiver does not receive the data properly. In such cases, the data needs to be transmitted again by the receiver. For Example, Walkie-Talkie, Internet Browsers, etc. Following are the advantages of using a half-duplex transmission mode:
Following are the disadvantages of using a half-duplex transmission mode:
3. Full-DuplexFull-Duplex is the data transmission mode in which the data can flow in both directions at the same time. It is bi-directional in nature. It is two-way communication in which both the stations can transmit and receive the data simultaneously. Full-Duplex mode has double bandwidth as compared to the half-duplex. The capacity of the channel is divided between the two directions of communication. This mode is used when communication in both directions is required simultaneously. For Example, a Telephone Network, in which both the persons can talk and listen to each other simultaneously. Following are the advantages of using a full-duplex transmission mode:
Following are the disadvantages of using a half-duplex transmission mode:
According to the synchronization between the transmitter and the receiver: 1. SynchronousThe Synchronous transmission mode is a mode of communication in which the bits are sent one after another without any start/stop bits or gaps between them. Actually, both the sender and receiver are paced by the same system clock. In this way, synchronization is achieved. In a Synchronous mode of data transmission, bytes are transmitted as blocks in a continuous stream of bits. Since there is no start and stop bits in the message block. It is the responsibility of the receiver to group the bits correctly. The receiver counts the bits as they arrive and groups them in eight bits unit. The receiver continuously receives the information at the same rate that the transmitter has sent it. It also listens to the messages even if no bits are transmitted. In synchronous mode, the bits are sent successively with no separation between each character, so it becomes necessary to insert some synchronization elements with the message, this is called "Character-Level Synchronization". For Example, if there are two bytes of data, say(10001101, 11001011) then it will be transmitted in the synchronous mode as follows: For Example, communication in CPU, RAM, etc. Following are the advantages of using a Synchronous transmission mode:
Following are the disadvantages of using a Synchronous transmission mode:
Parallel 2. AsynchronousThe Asynchronous transmission mode is a mode of communication in which a start and the stop bit is introduced in the message during transmission. The start and stop bits ensure that the data is transmitted correctly from the sender to the receiver. Generally, the start bit is '0' and the end bit is '1'.Asynchronous here means 'asynchronous at the byte level', but the bits are still synchronized. The time duration between each character is the same and synchronized. In an asynchronous mode of communication, data bits can be sent at any point in time. The messages are sent at irregular intervals and only one data byte can be sent at a time. This type of transmission mode is best suited for short-distance data transfer. For Example, if there are two bytes of data, say(10001101, 11001011) then it will be transmitted in the asynchronous mode as follows: For Example, Data input from a keyboard to the computer. Following are the advantages of using an Asynchronous transmission mode:
Following are the disadvantages of using an Asynchronous transmission mode:
According to the number of bits sent simultaneously in the network: 1. SerialThe Serial data transmission mode is a mode in which the data bits are sent serially one after the other at a time over the transmission channel. It needs a single transmission line for communication. The data bits are received in synchronization with one another. So, there is a challenge of synchronizing the transmitter and receiver. In serial data transmission, the system takes several clock cycles to transmit the data stream. In this mode, the data integrity is maintained, as it transmits the data bits in a specific order, one after the other. This type of transmission mode is best suited for long-distance data transfer, or the amount of data being sent is relatively small. For Example, Data transmission between two computers using serial ports. Following are the advantages of using a serial transmission mode:
Following are the disadvantages of using a serial transmission mode:
2. ParallelThe Parallel data transmission mode is a mode in which the data bits are sent parallelly at a time. In other words, there is a transmission of n-bits at the same time simultaneously. Multiple transmission lines are used in such modes of transmission. So, multiple data bytes can be transmitted in a single system clock. This mode of transmission is used when a large amount of data has to be sent in a shorter duration of time. It is mostly used for short-distance communication. For n-bits, we need n-transmission lines. So, the complexity of the network increases but the transmission speed is high. If two or more transmission lines are too close to each other, then there may be a chance of interference in the data, degrading the signal quality. For Example, Data transmission between computer and printer. Following are the advantages of using a parallel transmission mode:
Following are the disadvantages of using a parallel transmission mode:
Hence, after learning the various transmission modes, we can conclude that some points need to be considered when selecting a data transmission mode:
This is all about the various transmission modes in a computer network. Hope you learned something new today. That's it for this blog. Do share this blog with your friends to spread the knowledge. Visit our YouTube channel for more content. You can read more blogs from here. Keep Learning :) Team AfterAcademy! What unit used in the data transfer between devices that communicate on a network?In telecommunications, a protocol data unit (PDU) is a single unit of information transmitted among peer entities of a computer network. It is composed of protocol-specific control information and user data.
Which device transfer the data between the network?A router is a networking device that connects computer networks, for example, connecting a home network with the Internet. Routers are the workhorses that transfer packets of data between networks to establish and sustain communication between two nodes in an internetwork.
Which device is used for data communication?These devices must be capable of sending and receiving data over a communication medium. Examples of such devices include personal computers, mobile phones, laptops, etc. As we can see in Figure 11.1, four different types of devices — computer, printer, server and switch are connected to form the network.
What is used to transfer data packets between two networks?Detailed Solution. A router is a networking device that forwards data packets between computer networks. Routers perform the traffic directing functions on the Internet.
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