A system and method for discontinuous wireless communication. The system and method include estimating a first likelihood of channel collisions at start of a discontinuous channel interval, wherein the estimated likelihood of collision is increased when a transmission failure is detected during a portion of one or more previous channel intervals; setting a size of a contention transmission window at start of a current channel interval, according to the first estimated likelihood of channel collisions; estimating a second likelihood of channel collisions for a next channel interval; and dynamically changing the size of the contention transmission window for the next channel interval, according to the second estimated likelihood of channel collisions.