What Is Automatic Repeat ReQuest (ARQ)?

What is Automatic Repeat reQuest (ARQ)?

Understanding Automatic Repeat reQuest (ARQ) | DEFINITIONS

Understanding Automatic Repeat reQuest (ARQ)

Welcome to the “DEFINITIONS” category of our website, where we provide detailed explanations of various technical terms. In this post, we will delve into the world of Automatic Repeat reQuest (ARQ) and unravel the mysteries behind its functionality and significance in the realm of communication protocols.

What is Automatic Repeat reQuest (ARQ)?

Automatic Repeat reQuest, commonly known as ARQ, is an error control scheme utilized in communication systems. It is designed to detect and correct errors that may occur during the transmission of data between two communicating devices.

ARQ operates by employing acknowledgments and retransmissions to ensure the reliable and accurate delivery of data. When the sender transmits a data packet, the receiver acknowledges its successful receipt. If an acknowledgment is not received within a specified time frame or an error is detected, the sender automatically retransmits the packet. This process continues until the data is successfully received or a predetermined number of attempts have been made.

Key Takeaways:

  • ARQ is an error control mechanism used in communication systems to ensure the reliable delivery of data.
  • It involves the use of acknowledgments and retransmissions to correct errors and ensure successful transmission.

ARQ offers several important benefits in the field of communication protocols. Let’s take a closer look at some of these advantages:

The Advantages of Automatic Repeat reQuest (ARQ)

1. Error Detection and Correction: ARQ’s primary function is to detect and correct errors that may occur during data transmission. By using acknowledgments and retransmissions, ARQ ensures the delivery of error-free data, contributing to the overall reliability of the communication system.

2. Reliable and Accurate Data Transfer: The use of acknowledgments and retransmissions in ARQ guarantees that each data packet is successfully received before moving on to the next one. This ensures the accurate transfer of data, preventing any loss or corruption that may occur during transmission.

3. Synchronization and Flow Control: ARQ also assists in synchronizing the sender and receiver devices by regulating the flow of data. By utilizing acknowledgment signals, ARQ ensures that both devices are operating at an optimum pace, preventing any overload or congestion in the communication channel.

By combining these advantageous features, ARQ plays a crucial role in maintaining the integrity and efficiency of communication systems, particularly in scenarios where reliable data transfer is prioritized.


In summary, Automatic Repeat reQuest (ARQ) is a vital error control mechanism used in communication systems. It detects and corrects errors, ensuring reliable and efficient data transmission. ARQ’s use of acknowledgments and retransmissions allows it to provide accurate data transfer, synchronization, and flow control. With its remarkable benefits, ARQ stands as a cornerstone technology in maintaining the integrity of modern communication protocols.