The present disclosure generally relates to systems, methods and software for determining an optimal burst transmission time through a modem, such as a cable modem, a wireless access point, a node in a cable network, or a satellite communication link. Particularly, the present disclosure makes it possible for a burst of queued data, defined as data above a certain percentile of a monitored traffic rate, to be transmitted by the modem at a time that provides the best chance of avoiding a collision with a co-occurring burst of data from another user connected to the same modem. In an embodiment, the systems, methods and software disclosed herein use the optimal transmission time to replace a contention window transmission time, at least for bursty data, or they completely eliminate the need for contention windows, at least for bursty data.