Abstract: There is provided a timing entity for a communication network which includes a base station and a user equipment capable of communicating with each other over at least two carriers which have different temporal configuration of its uplink and downlink resources. The timing entity includes a control entity adapted for determining timing data defining a timing of a control signalling transmission which is related to a data transmission on a first carrier and which uses a resource of a first type on the second carrier. According to an embodiment the timing data specify for the control signalling transmission a time slot in which there is available a resource of the first type on the second carrier for the control signalling transmission. The control entity may be implemented in a base station and/or a user equipment.