Synchronous vs Asynchronous Transmission: Difference and Comparison

Key Takeaways

1. Synchronous transmission requires a common clock signal between the sender and receiver to synchronize data transfer. In contrast, the asynchronous transmission uses start and stop bits for each data frame to indicate the beginning and end of the transmission.
2. Synchronous transmission is more efficient for large data transfers, while the asynchronous transmission is better suited for smaller, sporadic data transfers.
3. Asynchronous transmission is more resilient to signal distortion and timing errors, as it relies on individual data frames to indicate the transmission start and stop points.

What is Synchronous Transmission?

Synchronous transmission is a transmission method in which data is transferred as a continuous stream of signals. In this method of transmission, data is transmitted at predefined time intervals according to a predefined clocking signal.

Synchronous transmission is a full duplex type of transmission. Synchronization is compulsory between the sender and receiver. There is no gap between data, so it is more efficient and reliable for transferring a large amount of data.

This data transmission method is used when vast amounts of data are needed to be transferred quickly. This provides real-time communication between a transmitter and a receiver. The data blocks are sent separately and clustered in blocks.

What is Asynchronous Transmission?

Asynchronous transmission is a data transfer method in which data is sent by the sender to the receiver using the flow control method. It is also known as the start/stop transmission.

This method does not use a predefined clocking signal to synchronize the sender and receiver data. It sends 8 bits or one character at a time.

In an asynchronous transmission method, data is transferred as packets and not in continuous data signals. This transmission method is highly flexible as it does not require synchronization between the sender and receiver.

Differences Between Synchronous and Asynchronous Transmission

1. Synchronous transmission is a data transfer method in which data is transferred as a continuous stream of signals along with timing signals. In contrast, asynchronous transmission is a data transfer method in which both the sender and receiver use the flow control method.
2. In synchronous transmission, users must wait for the sending process of one message to complete before getting a response from the receiver. In asynchronous transmission, users do not have to wait for a response.
3. In synchronous transmission, data is sent in blocks or frames, whereas in asynchronous transmission, data is sent in the form of characters or bytes.
4. Synchronous data transmission is fast compared to asynchronous data transmission, which is slow.
5. The time interval in a synchronous transmission is constant, whereas the interval in an asynchronous transmission is random.
6. In synchronous transmission, there is no gap between the data as they share a standard clock, whereas in asynchronous transmission, there is a gap between the data because of the start and stop bit feature.
7. Synchronous transmission is easy to design but costlier, whereas asynchronous transmission is complex in design but cheaper.

Comparison Between Synchronous and Asynchronous Transmission

Parameters of Comparison	Synchronous Transmission	Asynchronous Transmission
Definition	Synchronous transmission is a data transfer method in which a standard clock pulse is shared between transmitter and receiver for communication.	Asynchronous transmission is a data transfer method in which the sender and receiver have their internal clocks.
Data unit	Data is sent in the form of blocks or frames.	Data is sent in the form of characters or bytes.
Performance and cost efficiency	Synchronous transmission is a quick process, making it a costlier method.	Asynchronous transmission takes a long time to complete but is significantly inexpensive.
Data gap	There is no gap present between data in synchronous transmission.	There is a gap present between the data bytes in asynchronous transmission.
Complexity	It is easy to design synchronous transmission.	Asynchronous transmission is complex in design.

References

1. https://www.sciencedirect.com/science/article/pii/S0165168408003290
2. https://ieeexplore.ieee.org/abstract/document/9360839/