Smart buses for ubiquitous broadband satellite services in urban, suburban and highway environments

In this paper we present a scenario where a fixed earth station (hub) uses a DVB-S2 satellite link to transmit multimedia data to a fleet of buses (satellite users), which travel on fixed, pre- defined routes in urban, suburban, rural, and highway environments. Each bus is provided with a return channel for short communications with the hub. The system takes advantage from knowing the exact points where, due to fixed obstacles, a bus will not receive the signal for a period that exceeds a given threshold; in fact, this knowledge allows avoiding the transmission of data toward the specific bus, thus temporarily saving bandwidth for other users. The goal of this work is to compare, in terms of bandwidth saving, this "smart" system with another one, where a bus does not exploit the detailed description of its route, still maintaining the same Quality of Service (QoS).