contention slot
(Or contention period). Minimum time a {host} must transmit
for before it can be sure that no other host's {packet} has
collided with its transmission. If the maximum propagation
delay from one host to any other is T, then a host that starts
to transmit at time t0 may collide with a host that starts
just before t0 + T. The first host will not detect the
collision until time t0 + 2T.