Embodiments provide systems and methods for a probabilistic reporting mode, where an Optical Network Unit (ONU) sends a REPORT message only when it has data to transmit. The absence of a REPORT message from an ONU is treated by the Optical Line Terminal (OLT) as indicating absence of data to transmit at the ONU. In another aspect, embodiments include systems and methods for an unsolicited burst mode, where an ONU can be configured to transmit data in the upstream in an unsolicited manner. The unsolicited burst mode includes mechanisms to ensure that no data is lost due to potential collisions between ONUs.