The objectives of the study on "Scalable Video Coding Applications and Technologies for mobile satellite based hybrid networks" (SVConS) were as follows:
The main constraints on tools and methodologies to be applied for this study concerned two different areas:
During this study, the following four important reference use cases for SVC over DVB-SH were investigated:
For more details, including a description of the primary objective, the list of simulation parameters, and the main results, the reader is referred to the Executive Summary and/or the Final Report.
Within the SVConS project, a total of 11 use cases for SVC in DVB-SH and ETSI-SDR like systems were investigated. The main findings are as follows:
Future work in this area may deal with the following issues:
A high-level overview of the simulation platform used in this study is shown in the figure below. It consists of four major parts:
The main interactions between the different parts during a simulation run are as follows: For each offered multimedia service, the video content to be encoded in each time slicing round is chosen from a pool of test sequences. This selection process is done in a reproducible and statistically relevant manner, and the generated video sequences are stored as reference for the later quality evaluation.
The bench of Video Encoders then generates the corresponding RTP/UDP/IP stream for each service using the video coding format (e.g., AVC or SVC) specified at simulation startup. In addition, a (dummy) audio component is also inserted in each output stream. The overall generation process is controlled such that the resulting streams fulfil certain predefined bit rate and delay constraints, but also exhibit good quality across all services. The Service Control may also receive dynamic feedback from the IP packet simulator to update the bit rate target in each time slicing round, if required.
The generated test streams are fed to the IP packet simulator, whose task is to generate the delay and loss characteristics for each service based on the specific DVB-SH system configuration chosen at simulation startup. For this reason, the IP packet simulator contains a fully-featured model of the DVB-SH link layer processing done at the broadcast transmitter and the terminal receiver.
Emulation of the DVB-SH physical layer processing of the MPEG-2 transport stream(s) and the actual transmission process over the satellite and/or terrestrial link is handled by a separate module that communicates with the IP packet simulator in each time-slicing round. Besides realistic error flags at MPEG-2 TS level, this module supplies the necessary advances in transmitter and receiver timing due to the physical layer processing and propagation delay.
Finally, the bench of Video Decoders processes the received media streams at the output of the IP packet simulator and stores them for subsequent quality evaluation. The latter is then performed taking into account the original and the decoded sequences.
Work in the SVConS project was organized in five different phases:
The SVConS project was successfully completed at the end of 2010.