Methods and apparatus for an adaptable frame structure are disclosed, where a transmission frame consists of multiple subframes, each containing a downlink transmission period and an uplink transmission period. A downlink broadcasting signal is used to indicate the configuration of each subframe. The downlink and uplink period configuration in each subframe can be independently adapted to support applications with a variety of traffic patterns, from symmetric to highly asymmetric. A great variety of applications from normal two-way data communications to voice communications and video or data broadcasting can be supported efficiently in a single frequency band, while multiple frequency bands can be used to increase capacity or add more flexibility.