In
telecommunications, a
carrier sense multiple access with collision avoidance (
CSMA/CA) is a
network control
protocol in which (a) a
carrier sensing scheme is used, (b) a
data station that intends to transmit sends a
jam signal, (c) after waiting a sufficient
time for all stations to receive the jam signal, the data station transmits a
frame, and (d) while transmitting, if the data station detects a jam signal from another station, it stops transmitting for a random time and then tries again.
Source: from Federal Standard 1037C