A class of methods for sharing a data transmisSIon medium in which hosts transmit as soon as they have data to send and then check to see whether their transmisSIon has suffered a colliSIon with another host' s. If a colliSIon is detected then the data must be resent. The resending algorithm should try to minimise the chance that two hosts' s data will repeatedly collide. For example, the CSMA/CD protocol used on Ethernet specifies that they should then wait for a random time before re-transmitting. See also backoff. This contrasts with slotted protocols and token pasSIng. (1997-03-18)