Mobile multimedia communication and, in particular, wireless video streaming are the killer applications of the third and fourths generation mobile and wireless networks. These networks have a substantial different behavior in comparison with conventional wired networks due to the error-prone radio channel and the terminal mobility. Therefore, wireless networks typically provide low bandwidth and involve relatively high latencies. Furthermore the channel characteristics are time variant because of interferences, mobility and high terminal density in a cell. Consequently, there are high fluctuations of bandwidth and transmission delay. Albeit the known challenges of variations in throughput, delay and bursts of errors in wireless networks, which can dramatically reduce the observed quality at the receiver, mobile video streaming has been the focus of extensive research for years and is now in its beginning of proliferation. However many open issues still have to be addressed for mass commercial deployment. Several techniques have been proposed in order to improve the coding efficiency and hence the overall quality of streaming media. Employed in different components of the system, these techniques aim to provide more efficient, robust, scalable and low-latency mobile streaming video.
In this project, a new adaptive extendable video coding scheme (AdapXVid) for the wireless link will be proposed. The goal of our scheme is to achieve an optimum distribution of data between the source and channel coders in order to obtain a minimum distortion and hence the best quality of the received video data. This scheme uses a feedback mechanism by which the source coder chooses optimum parameter settings (i.e. quantization factor) for the fine granular scalability (FGS) to achieve target bit rate while the channel coder provides a better protection for more relevant parts of the data by using unequal error protection (UEP) and adapts to the loss characteristics by using appropriate number of redundant bits.
We use OPNET Modeler and its specialized Wireless and UMTS modules to simulate AdapXVid in wireless networks. OPNET will be especially helpful for us to easily introduce new components into the existing UMTS Network Model, to simplify getting access to the channel coding in UMTS, and to effectively perform simulation and analysis of our proposal. As the first step, the existing UMTS Network model will be extended by AdapXVid functionality. Extensive simulations will be carried out to produce the data to be processed. Finally, results will be viewed and analyzed to investigate the performance enhancement sourced from AdapXVid, to validate the correctness of the design and algorithms, as well as to exploit the optimal parameter settings.
Bei Fragen zu diesem Projekt wenden Sie sich bitte an .