Filecasting for streaming content delivery in IP datacast over DVB-H systems

In this paper we investigate the potential gain that can be obtained in DVB-H by delivering streaming content as a succession of time-constrained flies using Application Layer - Forward Error Correction (AL-FEC) for improving the reception for mobile terminals. Compared to the conventional approach with link layer MPE-FEC, this technique allows to increase the robustness of the DVB-H transmission not only as a function of the capacity devoted for error repair (FEC overhead), but also as a function of the number of data bursts coded jointly ("file" or, source data block, size). The main drawback of this approach is an increase of the network latency proportional to the source block size, that can be translated into a larger service access time, and, in the case of mobile TV, a larger zapping time between channels, which is currently seen as a crucial parameter for DVB-H usability. In this paper the performance of the proposed approach is evaluated using vehicular urban DVB-H field measurements. We evaluate the gain compared to MPE-FEC in terms of reduced Erroneous Second Ratio (ESR) of the streaming service as a function of the FEC overhead and the system latency introduced. Moreover, simulations have been performed to quantify feasible link margin gains.