is a fundamental error-control mechanism used in telecommunications and data link layers to ensure reliable transmission over unreliable communication links. Unlike Forward Error Correction (FEC) , which allows the receiver to correct errors, ARQ relies on the receiver identifying errors and requesting retransmission of data from the sender. This paper covers the primary types of ARQ protocols, their mechanisms, and performance tradeoffs. 2. Fundamental Mechanisms ARQ protocols operate based on two main principles:
) before needing an ACK. If a frame is lost, the receiver discards all subsequent frames, and the sender must retransmit all frames starting from the lost one. Better utilization than Stop-and-Wait. Cons: High retransmission overhead in poor channels. 3.3. Selective Repeat ARQ (SR) Better utilization than Stop-and-Wait
Automatic Repeat Request (ARQ): Reliable Data Transmission 1. Introduction protocol efficiency calculations
The sender transmits one frame and waits for an ACK before sending the next. Pros: Simple implementation. equations) or a ? Do youg.
ARQ is an indispensable tool for achieving reliable digital communication. While Stop-and-Wait is efficient for simple, low-delay networks, Go-Back-N and Selective Repeat are essential for modern high-speed networks. The hybrid approach (HARQ) offers the best balance of efficiency and reliability in modern wireless scenarios.
g., protocol efficiency calculations, equations) or a ? Do youg., mobile networks, satellite)?