Abstract: One example of the invention provides a data source apparatus that in use provides data of one or more types to a sink device via a data transport communications link, the data source apparatus selecting the types of data to be provided to the sink device in dependence on the type of data transport communications link over which the data is to be provided. In one example the data to be provided is user data derived from one or more user applications. For example, one type of user data may be user contact data. Another type of user data is user task list data. A further example of user data is calendar data. A further example of user data is media data, for example video data, or audio data.