The main theme of my research interests is the control of network resources and how this effects the interaction between the network, the application and the user. As the nature of applications has become more distributed, so the aspects of networking that allow applications to communicate and distribute information have become increasingly significant. Traditional networked applications have assumed that the network resources they need are always available. As the demand for network resources from applications increases, and the nature of the networks themselves changes (e.g. fixed networks vs. mobile networks), the applications must become (a) generally aware of their own connectivity and (b) sensitive to the demand for the limited resources in the network. This is especially true for mobile and wireless applications; for applications operating at every high levels of performance and so stressing the infrastructure on which they run; and for real-time applications with media flows that are sensitive to resource limitations within the network.