A method for wireless communications by an apparatus, comprising: generating one or more first frames that, collectively, include a set of parameters defining at least one broadcast target wake-up time, TWT, schedule and an assignment of one or more wireless nodes to one or more TWT groups to be serviced in different TWT service periods, SPs, associated with the at least one broadcast TWT schedule, wherein the generation comprises assigning the one or more wireless nodes to the one or more TWT groups, based on one or more preferred wake-up schedules of the one or more wireless nodes, wherein each wake-up schedule indicates availability of a corresponding one of the wireless nodes; and outputting, over a first interface, the one or more first frames for transmission; and characterised in that the method is further comprising: obtaining, over a second interface, at least a second frame indicating the preferred wake-up schedule of at least one of the one or more wireless nodes; or further comprising: obtaining, over a second interface, at least a second frame indicating a request from at least one of the one or more wireless nodes to change at least one of the assignment or a preferred wake-up time; and assigning or re-assigning at least one of the one or more wireless nodes to a TWT group based on the request; or further comprising: obtaining, over a second interface, at least a second frame comprising an indication of whether or not a wireless node prefers selecting its own TWT group; and assigning that wireless node to a TWT group based, at least in part, on the indication of whether or not that wireless node prefers selecting its own TWT group; or further comprising: generating at least one second frame comprising an indication of, for each broadcast TWT service period, one or more wireless nodes of a TWT group to be serviced; outputting the at least one second frame for transmission over the first interface; obtaining, over a second interface, at least a third frame from one of the one or more wireless nodes to be serviced, in response to the at least one second frame; and servicing wireless nodes from which third frames are received by the apparatus. generating one or more first frames that, collectively, include a set of parameters defining at least one broadcast target wake-up time, TWT, schedule and an assignment of one or more wireless nodes to one or more TWT groups to be serviced in different TWT service periods, SPs, associated with the at least one broadcast TWT schedule, wherein the generation comprises assigning the one or more wireless nodes to the one or more TWT groups, based on one or more preferred wake-up schedules of the one or more wireless nodes, wherein each wake-up schedule indicates availability of a corresponding one of the wireless nodes; and outputting, over a first interface, the one or more first frames for transmission; and characterised in that the method is further comprising: obtaining, over a second interface, at least a second frame indicating the preferred wake-up schedule of at least one of the one or more wireless nodes; or further comprising: obtaining, over a second interface, at least a second frame indicating a request from at least one of the one or more wireless nodes to change at least one of the assignment or a preferred wake-up time; and assigning or re-assigning at least one of the one or more wireless nodes to a TWT group based on the request; obtaining, over a second interface, at least a second frame indicating a request from at least one of the one or more wireless nodes to change at least one of the assignment or a preferred wake-up time; and assigning or re-assigning at least one of the one or more wireless nodes to a TWT group based on the request; or further comprising: obtaining, over a second interface, at least a second frame comprising an indication of whether or not a wireless node prefers selecting its own TWT group; and assigning that wireless node to a TWT group based, at least in part, on the indication of whether or not that wireless node prefers selecting its own TWT group; obtaining, over a second interface, at least a second frame comprising an indication of whether or not a wireless node prefers selecting its own TWT group; and assigning that wireless node to a TWT group based, at least in part, on the indication of whether or not that wireless node prefers selecting its own TWT group; or further comprising: generating at least one second frame comprising an indication of, for each broadcast TWT service period, one or more wireless nodes of a TWT group to be serviced; outputting the at least one second frame for transmission over the first interface; obtaining, over a second interface, at least a third frame from one of the one or more wireless nodes to be serviced, in response to the at least one second frame; and servicing wireless nodes from which third frames are received by the apparatus. generating at least one second frame comprising an indication of, for each broadcast TWT service period, one or more wireless nodes of a TWT group to be serviced; outputting the at least one second frame for transmission over the first interface; obtaining, over a second interface, at least a third frame from one of the one or more wireless nodes to be serviced, in response to the at least one second frame; and servicing wireless nodes from which third frames are received by the apparatus.