The invention relates to transmission and reception of data in a wireless communication system. In particular, the predetermined number of repetitions of the same data portion is transmitted over the wireless interface. The receiving device receives the repetitions, attempts their decoding and checks whether the decoding was successful. If the decoding was successful after the predetermined number of repetitions or less, a positive acknowledgement is generated. In addition, a feedback including a bundle size information is generated and transmitted. The bundle size information includes a number of repetitions, smaller or equal to the predetermined number, after which the decoding was successful. The feedback is transmitted to the data transmitting device which may adapt the predetermined number of repetitions accordingly. The invention enables efficient control of the number of repetitions applied which is particularly advantageous for coverage enhancement purposes.