AbstractsComputer Science

Recently the need for ultra high data rate wireless networks has increased. With the improvement of CMOS technologies, 60 GHz WPANs has become more interesting commercially. 60 GHz radio operates at wave lengths in the order of millimeters at a frequency band between 57 and 64 GHz. The 802.15.3 MAC is specified to provide high data rate and also have QoS capabilities. Because of physical properties of 60 GHz radio, humans and other object are sources for blocking and shadowing of the wireless channel. The 802.15.3 MAC does not specify how these kind of connection issues can be solved. To overcome problem of shadowing and blocking, changes have to be made to the 803.15.3 MAC and route discovery is needed in case two node lose their peer-to-peer connection. This thesis provides a solution for blocking of a connection between two devices in a piconet by using a multi-hop solution. First a route discovery process is initialised. If needed intermediate nodes are used to reconnect the devices. In case either the source or the destination is excluded from the piconet, a new piconet is formed, creating a mesh network. The newly created piconet contains devices which are in reach of the source and the destination. A measurement for the performance of the route discovery process is the time needed to find the optimal route between the source and the destination. A mathematical model has been derived for route discovery during the CAP using directional antennas. In Opnet Modeler the route discovery has also been simulated using the 802.15.3 MAC extended with directional antennas. The mathematical models do not exactly produce the same values for the delay as the simulation. However, the mathematical model and the simulations show the same behaviour. Furthermore, both the mathematical model and the simulation show that for small networks initialising a route discovery process is quick enough to overcome blocking.