Method of transmitting scheduling information in TDD system

A method of transmitting, by a user equipment, data in a time-division-duplex (TDD) mobile communication system using a plurality of radio frames, each including downlink subframes reserved for downlink and uplink subframes reserved for uplink, the method comprising:

• receiving, from a base station, scheduling information, including an uplink indicator and an uplink resource assignment, on a downlink control channel within a downlink subframe in a radio frame, wherein the uplink indicator identifies a position of at least one uplink subframe for which an uplink resource is assigned from a position of the downlink subframe;
• and
• transmitting mobile communication data to the base station in the at least one uplink subframe,
• wherein the uplink resource assignment identifies a radio resource to be used for uplink data transmission in the at least one uplink subframe, and
• wherein a number of downlink subframes in the radio frame is less than a number of uplink subframes in the radio frame.