What is Asynchronous Communication?
Asynchronous communication in networks refers to a communication method where data is transmitted between devices at different rates and times, rather than in a synchronous manner. In synchronous communication, data is transmitted in real-time, with the sending and receiving devices communicating with each other in a continuous and immediate exchange.
In asynchronous communication, data is transmitted in a non-real-time manner, with the sending and receiving devices communicating with each other at different times. The sender may send a message or data packet, and the receiver may receive it later, after a period of time. The sender and receiver do not need to be communicating at the same time, which can help to improve communication reliability and reduce the impact of network congestion.
Asynchronous communication is commonly used in computer networks and internet communications. For example, email is an asynchronous communication method, as messages can be sent and received at different times. Similarly, file transfers, such as downloading a file from the internet, are also typically performed asynchronously.
Asynchronous communication has several benefits over synchronous communication. Firstly, it allows for communication to occur in a more flexible manner, with the sender and receiver communicating at different times, as needed. This can help to reduce network congestion and improve communication reliability, as data packets are not lost or delayed due to network congestion.
Furthermore, asynchronous communication can also help to reduce the impact of network latency, as data can be transmitted at different times and in smaller packets, rather than in large and continuous streams of data. This can help to improve communication efficiency and reduce the impact of network latency on the speed and performance of communication.
Simplified Example
Asynchronous in blockchain can be compared to playing a game of basketball with your friends. When you play, each player takes turns shooting the ball, one at a time. This means that each player has to wait for their turn before they can shoot the ball. In the same way, with asynchronous blockchain, each transaction is processed one at a time, meaning that each transaction has to wait for its turn to be processed. Just like with basketball, everyone gets their turn, but it may take a little bit of time for each player to get to shoot the ball.
History of the Term "Asynchronous communication"
The precise origins of the term "asynchronous communication" are somewhat unclear, but it is thought to have surfaced in the mid-20th century, aligning with the advent of new communication technologies that permitted delayed or non-real-time interactions. Prior to this development, communication primarily adhered to synchronous patterns, involving real-time exchanges where participants shared messages simultaneously.
The term "asynchronous" derives from the Greek roots "a-" denoting "without" and "synchronos" signifying "together." In the realm of communication, it denotes the absence of simultaneity, indicating that messages are transmitted and received at different points in time. This stands in contrast to synchronous communication, characterized by immediate message exchange and rapid response expectations.
Examples
Asynchronous Transactions in a Public Blockchain: In a public blockchain such as Ethereum, transactions are processed asynchronously. This means that transactions are not processed in a linear or sequential manner, but rather they are processed in parallel. When a user initiates a transaction, it is broadcast to the network and added to a queue of unconfirmed transactions. The network's nodes then work to validate and include the transaction in the next block to be added to the blockchain. This allows for a high degree of scalability and ensures that the network can process a large number of transactions in a short amount of time.
Asynchronous Communication in a Decentralized Application: Decentralized applications (dApps) built on a blockchain often use asynchronous communication to ensure the smooth functioning of the application. For example, a decentralized exchange may use asynchronous communication to allow users to trade assets in real-time, even when the network is congested with transactions. The exchange can process transactions asynchronously, updating the user's balances in real-time and executing trades as soon as the necessary conditions are met.
Asynchronous Consensus in a Private Blockchain: In a private blockchain, participants may require a higher degree of control over the consensus process. In these cases, asynchronous consensus mechanisms may be used to ensure the smooth functioning of the network. For example, in a consortium blockchain, a group of pre-approved participants may agree to a consensus mechanism that allows for asynchronous consensus, such as practical byzantine fault tolerance (PBFT). This allows the network to process transactions more efficiently, as the consensus process can occur in parallel, without waiting for a linear sequence of confirmations.