Ethernet’s CSMA/CD (more)
Jam Signal: make sure all other transmitters are aware of collision; 48 bits;
Goal: adapt retransmission attemtps to estimated current load
- heavy load: random wait will be longer
first collision: choose K from {0,1}; delay is K x 512 bit transmission times
after second collision: choose K from {0,1,2,3}…
after jth collision: choose K from {0, ..., 2j-1}
after ten or more collisions, choose K from {0,1,2,3,4,…,1023}