Automatic Repeat Request (ARQ)
Process of requesting that a data transmission be resent
Main ARQ protocols
- Stop and Wait ARQ (A half duplex technique)
- Sender sends a message and waits for acknowledgment, then sends the next message
- Receiver receives the message and sends an acknowledgement, then waits for the next message
- Continuous ARQ (A full duplex technique)
- Sender continues sending packets without waiting for the receiver to acknowledge
- Receiver continues receiving messages without acknowledging them right away