RRM for Filecasting Services in Hybrid DVB-H/3G+ Systems

This article investigates efficient broadcast delivery of file download (filecasting) services in hybrid broadcast and cellular systems formed by a DVB-H network and an evolved 3G+ cellular network with HSDPA and MBMS capabilities. In particular, we investigate the delivery cost savings that can be achieved using HSDPA and MBMS to repair errors of the initial DVB-H broadcast transmission. In a realistic scenario, there may be users that experience significantly worse DVB-H reception conditions than the majority, such that it may be more efficient to serve them through the cellular network. To enable an easy and efficient implementation of the repair mechanisms in the hybrid DVB-H/3G+ system, we adopt application layer forward error correction (AL-FEC) with Raptor coding. With AL-FEC specific packets are not required to be retransmitted, and repair transmissions consist of additional repair packets that can be used for all users. Hence, repair data can be seamlessly delivered with unicast HSDPA, multicast MBMS, and broadcast DVB-H transmissions. Furthermore, AL-FEC provides a multiburst protection of the DVB-H transmission to exploit the time diversity of the mobile broadcast channel.