Difference between CSMA CD and CSMA CA


The media access controller (MAC) is the hardware implementation of the protocol defined for the media access control which is used in the case of networks shared with several nodes available for communication using a single physical support. The method has evolved from ALOHA Ethernet and two variants have been defined to deal with different scenarios. Among them, CD CSMA and CSMA CA are widely deployed in many networks such as Ethernet. The sense of operator, as defined here, is the case where the physical layer listens to an Ethernet cable before transmitting data via the network.

CSMA CD (collision detection by multiple access with carrier detection)

This multiple access method is used in cable networks because it is possible to detect a collision, then to proceed in the same way in local networks and wide networks. This is used by IEEE 802.3 standard Ethernet networks in which each node monitors traffic on the line and if no traffic is available, a particular node can transmit. But at the same time, if two people are trying to transmit, this is called a collision. This situation is detected by all the nodes on the given network. After that, the stations that have had the collision will attempt to return the data after a variable random time interval for each node. If a collision occurs again, the random time taken is increased and waits again. This is the procedure used in CSMA CD networks and the method has no deterministic capacity.

CSMA CA (collision prevention by multiple access with carrier detection)

This is the multiple access scheme used in the Layer 2 access method, in which the following method is used when nodes try to transmit simultaneously in a shared network. Here, the node which wishes to transmit must first listen to the medium for a predetermined period to assess the state of the channel. If the channel is inactive, the node is able to transmit. Otherwise, the channel is said to be busy and the node must wait for the channel to go into standby mode. This is implemented in IEEE 802.11 wireless local area networks and other wireless networks, which is preferable since wireless networks cannot detect collisions during transmission, like wired networks. Thus, the implementation of the CSMA certification authority will improve the deletion of packets in wireless networks.

Difference between CSMA CD and CSMA CA

  1. The CSMA CD is used in wired local area networks and CSMA CA used in wireless local area networks and other types of wireless networks.
  2. The CSMA CD is standardized in IEEE 802.3 and CSMA CA is standardized in IEEE 802.11 .
  3. CSMA CD will take no action to prevent the transmission collision until it has occurred, while CSMA CA takes measures to avoid any collision, the latter having no way of knowing whether a collision occurred

Post a Comment