Chapter 4. MAC Sublayer. 고려대학교 네트워크 연구실. The Medium Access Sublayer. The medium access sublayer. The key issue is how to determine who gets to use the channel when there is competition
The Medium Access Sublayer
Difference- time is divided up to discrte slots into which all frames must fit. Pure aloha don’t require global time synchronization.
-Stations listen for a carrier
-resolve the contention for the channel
without any collisions
Delay at low load and channel efficiency at high load
-narrow channel-control to signal the station
-wide channel-output data frame
-more efficient to do channel allocation per call than per frame
-voice, data,and fax can be integrated into a system.
-less bandwidth per channel because of compression.
-transmission quality by error-correction codes
-encryption for security.