Various example embodiments are disclosed herein. According to an example embodiment, an apparatus may include a wireless interface, and a controller, the apparatus being configured to: transmit a downlink subframe of a frequency division duplex (FDD) frame to one or more mobile stations in a wireless network, each wireless station being assigned to one of a plurality of groups, such as, for example, one of group 1 or group 2, the downlink subframe including at least: a group 1 portion and a group 2 portion, wherein a group boundary between the group 1 portion and the group 2 portion of the downlink subframe is variable, at least one of the group 1 portion and the group 2 portion including a group boundary information identifying a location of the group boundary or a location of the group 2 portion in the downlink subframe.