Networks are a shared system.
When there is sharing, there is interaction.
Interaction in networking is the sending of information.
When this information is sent at the same time, on the same line, by different people it can cause problems.(lets call them collisions of data on the same wired/wireless network)
These problems need to be solved by a protocol to prevent these collisions, hence CSMA/CD and CSMA/CA
Both use a system of sending and receiving data packets (information)
Both use Carrier Sensing ie Is there a carrier
Both use Multiple Access ie others users around
CSMA/CD is for wired or ethernet networks.
CSMA/CD it provides a listen, then transmit system
CSMA/CD, if there is a collision, it waits a random time .5-10 secs, then sends again.
CSMA/CD, each computer waits a different random time, then sends again.
Eg 1, computer 1 in computer lab 1 wants to send data to the internet, eg a google search
Eg 1, computer 2 in computer lab 1 also wants to send data to the internet, eg a goodle search
Eg1, there could be a collision down the ethernet cable if they both click search at the same time.
CSMA/CA is for wireless networks.
CSMA/CA uses the Wireless Access Point to control who sends and when they are clear to send.
Eg 2, iPad 1 in room 1 wants to send data to the internet, eg a google search
Eg 1, iPad 2 in room 1 also wants to send data to the internet, eg a goodle search
The WAP will get a ready to send from iPad1 and iPad2 at the same time.
The WAP will give the 'clear to send' to iPad1
The WAP will then give the 'clear to send' to iPad 2.