In the previous article, we have discussed Serial and Parallel Transmission. As we know in Serial Transmission data is sent bit by bit, in such a way that each bit follows another. It is of two type namely, Synchronous and Asynchronous Transmission. One of the major differences is that in Synchronous Transmission, the sender and receiver should have synchronized clocks before data transmission. Whereas Asynchronous Transmission does not require a clock but it adds a parity bit to the data before transmission.
Content: Synchronous Vs Asynchronous Transmission
|Basis for Comparison||Synchronous Transmission||Asynchronous Transmission|
|Meaning||Sends data in the form of blocks or frames||Sends 1 byte or character at a time|
|Gap between the data||Absent||Present|
|Examples||Chat Rooms, Video Conferencing, Telephonic Conversations, etc||Letters, emails, forums, etc|
Definition of Synchronous Transmission
In Synchronous Transmission, data flows in a full duplex mode in the form of blocks or frames. Synchronization between the sender and receiver is necessary so that the sender know where the new byte starts (since there is no gap between the data).
Synchronous Transmission is efficient, reliable and is used for transferring a large amount of data. It provides real-time communication between connected devices. Chat Rooms, Video Conferencing, telephonic conversations, as well as face to face interactions, are some of the examples of Synchronous Transmission.
Definition of Asynchronous Transmission
In Asynchronous Transmission data flows in a half duplex mode, 1 byte or a character at a time. It transmits the data in a continuous stream of bytes. In general, the size of a character sent is 8 bits to which a parity bit is added i.e. a start and a stop bit that gives the total of 10 bits. It does not require a clock for synchronization; rather it uses the parity bits to tell the receiver how to interpret the data.
It is simple, fast, economical and does not require a 2-way communication. Letters, emails, forums, televisions and radios are some of the examples of Asynchronous Transmission.
Key Differences Between Synchronous and Asynchronous Transmission
- In Synchronous Transmission data is transferred in the form of frames on the other hand in Asynchronous Transmission data is transmitted 1 byte at a time.
- Synchronous Transmission requires a clock signal between the sender and receiver so as to inform the receiver about the new byte. Whereas, in Asynchronous Transmission sender and receiver does not require a clock signal as the data sent here has a parity bit attached to it which indicates the start of the new byte.
- Data transfer rate of Asynchronous Transmission is slower than that of Synchronous Transmission.
- Asynchronous Transmission is simple and economic whereas, Synchronous Transmission is complex and expensive.
- Synchronous Transmission is efficient and has lower overhead as compared to the Asynchronous Transmission.
Both Synchronous and Asynchronous Transmission have their advantages and disadvantages. Asynchronous is simple, economical and used for transmitting a small amount of data whereas, Synchronous Transmission is used for transferring the bulk of data as it is efficient and has less overhead. Hence, we conclude that both Synchronous and Asynchronous Transmission are necessary for data transmission.