Disclosed in a method for establishing a time domain structure of a frame in a heterogeneous TDD systems environment. In other words, in a situation of coexisting heterogeneous systems comprising a first system corresponding to an existing TDD system and a second system corresponding to a new system, a method is provided for establishing a time domain structure of a second frame for the second TDD system mode to enable it to coexist with a first frame for the first TDD (Time Division Duplex) system mode, that comprises obtaining information for the first supported system type and a first ratio between the downlink region and the uplink region of the first frame structure, and then, according to the obtained information, establishing a second ratio between the downlink region and the uplink region of the second frame structure for the second system. Further, particular numerology is provided for said method.