This paper discusses the use of conventional datacasting and explores the feasibility of using datacasting for mobile users.
This paper addresses the feasibility of using conventional datacasting for mobile users. Conventional datacasting employs the excess bandwidth from digital television signals for use in one-way data transmission and is successfully being used for high-speed downloads at fixed locations. To explore the feasibility of using datacasting for mobile users, datacasting receivers and data logging equipment were installed in emergency vehicles, and performance characteristics over a wide range of operational conditions were recorded. The authors provide summary conclusions from that study, along with details about the network infrastructure and the equipment used. Starting with an introduction to datacasting, the authors describe the datacast network infrastructure; the process of selecting in-vehicle equipment for measurements; the effects of rain on datacast reception; new datacast modulation schemes; datacast reception in the mobile environment; and two-way datacast systems. The authors conclude that datacasting can provide an addressable, high-speed downlink channel to mobile users over a wide geographical region with reasonably priced, in-vehicle equipment, and that even in its current form, a signal is available in a sufficient region of a television transmitter’s coverage area to enable it to be a useful tool for disseminating large quantities of data. The authors also suggest that improvement in channel performance, which will likely result from new modulation schemes and antenna designs, should make the datacast channel a valuable and dependable resource for mobile users.