Future wireless systems will need to support diverse big data and Internet of Things (IoT) applications with diverse quality-of-service (QoS) requirements. Novel designs across the protocol stack are required for effective and efficient QoS provision. We introduce here a unique data-oriented approach for the design and analysis of advanced wireless transmission technologies. In our approach, unlike the conventional channel-oriented approach, we optimally design transmission strategies for individual data-transmission sessions, considering both the QoS requirement and the instantaneous operating environment. The resulting design can effectively satisfy highly stringent performance and efficiency requirements of future wireless applications.