Providing QoS for publish subscribe communication in dynamic ad-hoc networks

With the proliferation and miniaturization of electronic d evices that today pervade almost all areas of our everyday life, wireless communication receive d a growing importance to interconnect them. Especially so-called ad hoc networks and collabo ration allow for a variety of new applications. An important goal thereby is to enable wirele ss communication and access to different services without the need for a fixed infrastructure. This is especially important if such an infrastructure can only be deployed at high costs are has b een destroyed in a disaster. For the successful use of a service it is first necessary to find mat ching service provers for a user. The publish/subscribe communication scheme provides an id eal solution for this problem as it abstracts from physical nodes and defines communication rel ationships based on the used data. In addition some services require a minimum quality of servi ce to operate appropriately. In the contrary we have the inherent unreliable nature of the share d wireless medium and the dynamics of the network topology caused by the node mobility. In this thesis we will develop communication protocols to pr vide publish/subscribe communication with certain QoS guarantees in a mobile ad hoc network . We will start with a investigation of the properties of a IEEE 802.11 standard compliant multihop network in order to describe the problems and effects that can be experienced in practice as a model. The hereby gained knowledge will also be used to build a realistic simulation t hat provides the basis for the testing and evaluation of the developed protocols. The simulation w ill be complemented by real-world experiments to verify the results of different aspects of th e system. In order to provide QoS guarantees we will combine a continuous monitoring of the li nk quality to our neighbor nodes, a cooperative estimation and coordination of the bandwidth u tilization, and an online monitoring of the end-to-end properties. The developed communication pr tocols only rely on actual measured properties of the network. Upon these basic functions we will realize a publish/subscribe communication using multicast trees. We will use machine-r eadable content descriptions to minimize the processing overhead on intermediate nodes and he ce the end-to-end delay. The developed protocols will be implemented as independent mod ules of a portable, event-based middleware. This middleware allows a dynamic composition a nd configuration of individual modules at run-time in order to consume only the resources re quired for a certain use case.