Realtime mobile sharing of multimedia and context

Today’s inter-connected networks enable feature-rich applications that adapt according to situational and environmental changes, and the networks and objects that are discovered. These so-called pervasive applications can be composed from both locally and globally available multimedia resources such as audio and video, web services and context sources. Context sources in these pervasive applications can vary from your mobile phone’s sensors to dedicated sensor networks deployed in buildings and vehicles, sensor nodes attached to beings and objects, and events generated from devices and applications. The sharing of resources and the dynamic changes in these pervasive applications pose a number of challenges on the enabling infrastructure. This thesis focuses on methods for realtime sharing of wireless access networks, sensor information and multimedia among applications on mobile devices. We propose to use application-level techniques to support mobility and sharing and enable using lower-level techniques where available. Our contributions include methods and supporting communication architectures for efficient sharing of wireless access networks, multimedia and wireless sensor networks. Additionally, we contribute a reasoning framework to compare and combine communication architectures that support pervasive applications. In short the main contributions of this thesis are the following: 1. Sharing bandwidth in a wireless network: We propose a bandwidthdistribution mechanism for broadband access technologies that uses realtime characteristics of the network medium and feed-forward control mechanisms. 2. Mobility and sharing of wireless sensor networks: We analyse the mobility and sharing of wireless sensor networks in logistic and person monitoring scenarios. We provide guidelines for dealing with mobile and overlapping wireless sensor networks and the most promising scheme for