Random Access protocols o When node has packet to send e Transmitat full channel data rate R o No a priori coordination among nodes o Two or more transmitting nodes "collision o Random access MAC protocol specifies e How to detect collisions e How to recover from collisions(e.g, via delayed retransmissions) o Examples of random access mac protocols e Slotted aloha e ALOHA e CSMA, CSMA/CD, CSMA/CA 5: DatRandom Access Protocols  When node has packet to send  Transmit at full channel data rate R  No a priori coordination among nodes  Two or more transmitting nodes ➜ “collision”  Random access MAC protocol specifies:  How to detect collisions  How to recover from collisions (e.g., via delayed retransmissions)  Examples of random access MAC protocols:  Slotted ALOHA  ALOHA  CSMA, CSMA/CD, CSMA/CA 5: DataLink Layer 5-15