Optimization of Multiservice Scheduling for Variable Bit Rate Video Transmission in DVB-H Systems

Digital Video Broadcasting for Handheld terminals (DVB-H) is assuming an ever growing importance for digital video transmission over wireless terminals. In such a context, Time Slicing has been implemented to achieve a better power saving and manage handover. Specifically, a generic user transmits bursts of data, interspaced by time periods in which no data are transmitted. In this paper, to improve time sliced multiservice transmission effectiveness, the Variable Burst Time (VBT) algorithm is presented and discussed. It dynamically varies the whole set of stream Burst Durations according to input stream data, available channel bandwidth, receiving buffer size and eventually stream priority. Burst Durations are derived by the minimization of a Total Loss Function (TLF) representing the amount of losses of the whole service set. Numerical results show the VBT effectiveness if compared with the time sliced transmission recommended in the DVB guidelines, for different numbers, types and quality degrees of VBR streams, receiving buffer sizes and stream priorities. This suggests that VBT could be efficiently exploited for transmission of VBR streams in DVB-H systems.