Research activity in the area of wireless sensor networks has grown dramatically in the past few years, driven by advances in miniaturized hardware, and motivated by a vast array of potential applications. Only a small number of sensor networks have been deployed, and these are mainly used for research purposes. Early experiences highlight a lack of predictability in relation to cost, performance and reliability, raising concerns over their use in scenarios like mission critical production environments. This paper motivates the necessity of predictable and controllable wireless sensor networks. The key parameters that need to be predicted and controlled are identified. Furthermore, recent research results from UCCs Mobile & Internet Systems Laboratory are presented. These results show a) the building blocks needed to form a predictable and controllable sensor network and b) the methods that allow us to control and predict the sensor network behavior.