 Nodes A and
C
transmits
at the same time:
 The transmissions of nodes
A
and C
will collide and they
will back off
Suppose:
 Node A picked
0
 Node C picked
1

Then node A will
transmits first:
Node A will
complete its
transmission
 When node A is
done,
A will
transmit again
The node C will
also transmit.
Their transmissions
collide again and
back off:
Notice that:
 Node A transmits the
frame for the
first time, so:
 Node A will pick a
random number from the
range
range [0..1]

 Node C transmits the
frame for the
second time, so:
 Node C will pick a
random number from the
range
range [0..3]

 Problem:
 The likelihood that
node A will
transmit
before
the node C
is higher !!!
 The probability is
calculated in the
section below....

 This is unfair for
node C !!!


