Method and apparatus of transmitting control information

A user equipment of a wireless communication system, the user equipment comprising:

• a radio frequency (RF) unit being configured to transmit and receive wireless signals to and from a base station;
• a memory storing information being transmitted and received to and from the base station and parameters required for performing operations of the user equipment;
• and
• a processor connected to the RF unit and the memory, and being configured to control the RF unit and the memory, so as to operate the user equipment, and wherein the processor performs a method for transmitting control information comprising:
• receiving a first transmission timing information for transmitting a first control information associated with one or more first downlink component carriers from a base station;
• determining a second transmission timing information for transmitting a second control information associated with one or more second downlink component carriers by using the first transmission timing information and an additional transmission timing information;
• and
• transmitting control information on the one or more second downlink component carriers in dependence upon the second transmission timing information to the base station.