The present invention provides a method and system of periodic transmission of data between a first entity and a second entity within a mobile communication network. In order to increase transmission quality and take into account application characteristics of the network entities the first entity is able to obtain an adverse response from the second entity and provide an ancillary message to the second entity, where the ancillary message may have different contents depending on transmission circumstances, with the aim to increase the quality of transmission and to ensure the application requirements are met in different situations.