Q2: write short notes on Media Access Control
• The medium access sublayer is the bottom part of data link layer. The medium • access sublayer is also known as MAC (Medium Access Control) sublayer.
• When a common medium is shared by many stations, MAC layer plays a very important role. Without this control several stations transmits simultaneously could produce garbled messages.
• The media access control mechanism standardized by IEEE are implemented in the MAC sublayer of the Data link layer. It provides service to the LLC (Logical Link Control) sublayer and receives service from the physical layer below it.
• The basic functions of MAC sublayer is the media access control, error detection and station addressing. The physical transmission medium of a LAN is shared by the stations connected on the LAN.
• Media access control procedures are implemented to ensure that every station gets a fair chance to transmit and collision do not take place.
• There are several methods of media access control in LANs. Each method is applicable to specific LAN topology. In addition to the basic access procedures, the MAC layer also handles the frame delimiting, address recognition and error checking functions
• When number of user stations share a single transmission medium. This is called as multiple access communication. The transmission medium is broadcast in nature, so all other attached stations to the medium can receive the transmission from any given station.<