CSE 80N Lecture Notes - Lecture 25: Path Loss, Service Set (802.11 Network), Propagation Delay
Document Summary
Cmpe 80n-lecture 25 notes-random access protocols, ethernet and wireless links. Quiz 8 and 9 on friday, december 1. Review session last day of class, along with quiz 10. Encapsulation/decapsulation of packet header with direct and indirect delivery. When sharing a medium, controls who gets to transmit and when to transmit. If there is a packet that needs to be sent, it just sends it without listening to channel, causing a lot of collisions. With the sound of the sensing signal, the packets will not send if there is a busy signal in the channel. Hears that a collision happens so stops all transmission. Multiple access = sharing channel so everyone can hear everything. Collision detection = able to listen and see if collision will happen. If empty, transmit; if hear something, stop. Can still occur even when node thinks it"s quiet. Distance and propagation delay plays role in determining collision probability.
