CSMA With Collision Avoidance (CSMA/CA)
CSMA/CA is used in wireless (Wi-Fi) network. CSMA/CA is just similar to CSMA/CD but difference is that, the CSMA/CA detects collision instead of detection. So, CSMA/CA is just use for collision avoidance.
Working of CSMA/CA
In CSMA CA, whenever a station sends a frame to a channel
- First, it checks the status of medium (idle or busy). If the medium is busy, the station waits until the medium becomes idle.
- Second, if the channel is idle then station waits for an Inter-frame gap (IFG) amount of time and then sends the frame.
- Third, after sending the data frame, CSMA/CA sets a timer.
- In the end, station waits for positive acknowledgement from the receiver. If positive ACK receives before expiry of timer, then it is a successful transmission. Otherwise, station waits for a back-off time period and restarts the transmission.
Descriptive flow chart of CSMA/CA is given below
Difference Between CSMA/CD and CSMA/CA
|1.||It detects the collision on a shared medium.||CSMA CA is used to avoid collision on a shared channel.|
|2.||It is the collision detection protocol.||It is the collision avoidance protocol.|
|4.||It works in wired networks i.e. (802.3 Ethernet network cable)||It works in wireless networks (i.e. Wi-fi).|
|6.||It use the collision signals to resend the data.||It uses the timer to resend the data.|
|7.||It minimizes the recovery time.||It minimizes the risk of collision.|
|8.||The efficiency of CSMA/CD is high than CSMA.||The efficiency of CSMA/CA is similar to CSMA but less than CSMA/CD.|
|9.||It is more popular than CSMA/CA||It is less popular than CSMA/CD.|