On design of dependable communication protocols for wireless sensor networks

Sammanfattning: This thesis considers a problem of a design of dependable communication protocols for wireless sensor networks. In life critical applications of sensor networks, for example, connected to protection of critical infrastructures or intelligent transportation system dependability (i.e. reliability, availability, security) is the key performance requirement on the underlying communication system. In most of the cases the dependability properties of the system are evaluated a posteriori, after the communication protocols have been already implemented. This approach often leads to complete redesign of the system, which makes the development cycle long and costly. The contribution of this thesis is a proposed methodology for the design of dependable communication protocols. This methodology includes modularization of the existing protocols into functional components with known reliability and security properties. Given a set of defined components the methodology suggests rules for combining them into a protocol which satisfies the dependability requirements of the particular applications. The thesis demonstrates the application of the proposed methodology on an example of a medium access protocol synthesis for two real world applications. Finally, the performance of the resulting protocol should be evaluated prior to the deployment in the real network. Here the thesis highlights the current problem of the absence of a simulation environment for accurate performance evaluation of communication protocols in wireless sensor networks. The second contribution of the thesis is an integrated simulations environment named Symphony. Symphony allows simulating the same code which runs on the real hardware. Using this simulator the development cycle could be further reduced and the obtained performance results will better match the performance of the communication system in reality.