Answer #1

Medium Access controller, popularly known as MAC is defined as the hardware structure of all protocols used in a shared network having multiple nodes for fast data communication through one physical medium. ALOHA Ethernet has two major varieties defined under different scenarios namely, CSMA CA and CSMA CD – both of which are deployed in several networks. Carrier sense in such a scenario can be described as the situation whereby the physical layer communicates with Ethernet before transmitting information to other networks.

CSMA CA

Carrier sense multiple access collision avoidance is a multiple access protocol whereby nodes try to transmit data simultaneously on a shared network. In such a scenario, the node that is transmitting data first has to communicate with the medium to determine whether the channel frequency is idle. When the channel is idle, all the nodes are responsible for transmitting data. On the other hand, when the channel is busy the node will remain stagnant until there is an idle channel.

This is commonly seen in wireless networks since wireless networks are unable to detect collision when transmitting information to other wired networks. Therefore, implementing CSMA CA is a surefire way of improving packet dropping common in wireless networks.

CSMA CD

This is a multiple access protocol known as Carrier Sense Multiple Access Collision Detection. This method is popular because it can detect collision within the network then implements the use of WANs and LANs. It is used on a standard Ethernet network whereby each node has to monitor the line so they can transmit data. When two nodes transmit simultaneously, collision is bound to occur. However, such a situation is averted beforehand in any given network provided CSMA CD has been implemented.

Network

CSMA CA has a centralized ISP of IEEE 802.11 whereas CSMA CD has an ISP of IEEE 802.3. Additionally, CSMA CA will take action to prevent collision but CSMA doesn’t take any action to prevent collision.

Answered By: daniel [554 ]