Design and Realization of a Prototype Hardware Platform for ...

The MegaWatch Wireless PlatformMaster's Thesis - Emanuel Corthay3 Background3 BackgroundIn this section, today’s classical wireless network topology is presented, as well as the nextgeneration, with its possible applications. A quick overview of existing wireless standard ispresented.3.1 Today’s Wireless Network SystemsNowadays, almost all the wireless networks are infrastructure network. Each mobile unitcommunicates with an operator base station, the fixed infrastructure. Communications betweenmobile nodes, even if they are very close to each other, are not possible. The GSM cellular phonesystem [1] is a typical example of such an infrastructure, an operator maintained wireless network.The following picture shows how a transmission from one cell phone to another takes place. Evenwhen they are 1 meter apart from each other, the transmission always go through the base station,then the mobile operator fixed network concentrator and back to the second cell phone.MSCMobileStationBaseStationMSCMobileSwitchingCenterFigure 2 Cellular Phone Infrastructure Network3.2 The Next Generation Ad-hoc Network TopologyIn the Ad Hoc network topology, each unit can receive and transmit directly to its neighbours.Each unit then runs an ad-hoc algorithm to select the best route to reach a given destination,forwarding a message from one unit to the other to the final recipient. Every node can act as arelay to form a dense network.10 / 83