Wireless CSMA/CA

CSMA/CA Algorithm

Overview

• CSMA/CA stands for Carrier Sense Multiple Access with Collision Avoidance.
• Unlike CSMA/CD (Collision Detection), CSMA/CA does not detect collisions once they occur. Instead, it aims to avoid collisions before they happen.

How CSMA/CA Works

• Inter Frame Space (IFS): All devices must wait for a specific amount of time, called an Inter Frame Space (IFS), before they can transmit data.

  • Short IFS: Used by some applications for quicker transmission.
  • Long IFS: Used by other applications that might need more time before transmission.

• Collision Avoidance Mechanism:

  • If two devices attempt to transmit at the same time, the device with the shorter IFS will go first.
  • This reduces the likelihood of collisions by prioritizing transmissions based on the IFS.

Key Points

• IFS Values: Vary depending on the technology and application.
• Collision Avoidance: By regulating transmission timing and prioritizing based on IFS, CSMA/CA helps manage network traffic and minimize collisions in wireless networks.