JMU
Automatic Repeat Request (ARQ)
An Introduction


Prof. David Bernstein
James Madison University

Computer Science Department
bernstdh@jmu.edu


Motivation
Common ARQ Schemes
Stop-and-Wait ARQ
Stop-and-Wait ARQ (cont.)

An Example

images/stop-and-wait-ARQ.gif
Go-Back-N ARQ
Go-Back-N ARQ (cont.)

Example of a Lost/Corrupted Frame

images/go-back-n-ARQ.gif
An Analysis of Go-Back-N ARQ
Selective-Repeat ARQ