In one embodiment, a parent device in an unaligned wireless network may determine a superframe comprising a header timeslot followed by a plurality of sub timeslots. The parent device may transmit, to a plurality of child devices in the unaligned wireless network, a beacon during the header timeslot, wherein the beacon comprises i) synchronization information used by the plurality of child devices to synchronize to the header timeslot and ii) reservation information that indicates one or more reserved sub timeslots of the plurality of sub timeslots. The parent device may receive, from a particular child device of the plurality of child devices, a message during a particular sub timeslot of the plurality of sub timeslots that is different than the one or more reserved sub timeslots.