Wireless sensor networks are currently the subject of intense research and many prototype installations are currently investigated. These existing sensor network installations have in common that they are not considered time critical. No immediate action has to be undertaken as a response to the received data. However, many future application areas of wireless sensor networks such as plant automation and control, traffic management or medical applications require this feature. In such environments, data has to be transported reliable and in time through the sensor network. In other words, performance guarantees regarding a variety of network parameters are required. Due to the lack of appropriate models, components and protocols it is currently very difficult to construct and operate a wireless sensor network with a controlled performance. The goal of this work is to devise such models, components and protocols that allow us to operate a performance controlled sensor network.