Application-Level Data Dissemination in Multi-Hop Wireless Networks

We investigate different schemes for data dissemination in multi-hop ad-hoc networks using network coding. We study the performance of these schemes in terms of the completion time when a set of data packets must be disseminated from a single source to all nodes in a multi-hop network, i.e. a network where at least one node is several hops away from the source. Therefore some network nodes must relay information to other nodes that are farther away from the source. In this setting, a relay node does not send a particular data packet, but a linear combination of the packets that it has previously received. The selection of such relays has a significant impact on performance. We present a graphical simulator based on OpenGL that allows to study performance and illustrate the status of network nodes in real time during the dissemination of an image file. Features of real-life ad-hoc networks such as packet losses and collisions are taken into consideration in our simulator. Numerical results are presented for simple linear meshed networks and for arbitrary topologies. Results indicate that schemes promoting parallel non-interfering transmissions complete the dissemination process faster.