Study On Multimedia Traffic Modeling Prediction And Related Issues

The rapid development of the information techniques by wideband networks has laid a steady foundation for more extensive use of multimedia services. To solve the problems of wideband networks' structure designing, optimizing performance and selecting parameters requires much higher demands on multimedia service theoretical modeling and real-time prediction. On the other side, to maximize the quality of multimedia services requires the full consideration of the special characteristics of multimedia network services by network resource administrative organs and routing mechanism.From the standpoint of service providers, this dissertation studies the problems of the modeling for multimedia video service and the prediction. Moreover, it proposes how to improve the schemes of wireless multimedia network in call admission and handoff management according to characteristics of multimedia services. Finally, the routing algorithm proposed in this thesis is analyzed by using percolation theory. The major achievements and innovative points in this dissertation are outlined as fellows:A novel and fast method of detecting algorithm for Variable Bit Rate (VBR) video traffic with chaotic characteristics is proposed. By this method, the real data pretreatment and fast calculations are adopted under the premise to ensure the correctness of the detected result. By calculation with simulated actual data with algorithm, this method shows good performance in correctness and real-time capability. By considering the conclusion that GOP series of VBR video traffic includes chaotic time series with noise, we can divide the GOP series of VBR video traffic into two parts: chaotic characteristic part and noise part. Based on this analysis, a novel model for the GOP series of VBR video traffic based on chaotic theory is proposed. In the process of modeling, the algorithm uses chaotic series to approach the target series and then predicts the remaining part. The model's performance is acceptable in the prediction of error, auto-covariance function and Hurst effect. Compared with AR model, the proposed model considers the long-range dependence and short-range dependence characteristic of video traffic at the same time. The predicted traffic remains approximately the same hurst effect as the actual video traffic.In order to predict the video traffic in real-time circumstance, a novel Dynamic step-size Least Mean Square algorithm (DLMS), which does not depend heavily on the transcendental statistical parameters like some traditional traffic prediction algorithm, is proposed. The proposed algorithm can predict the video traffic on the long-time scale of GOP. The algorithm can adjust the step size by the predicted error from the feedback and does not need any transcendental statistical parameters. So it is fit for real-time prediction. Simulation result shows that performance of the algorithm is improved significantly. Based on it, a combined video traffic prediction algorithm which can utilize the strongpoint of both two algorithms is proposed. The method for prediction uses both the DLMS algorithm and the weighted, one-rank and local-region algorithm based on chaos theory. The next step would be taking the predicted result of the algorithm which shows better performance. Simulation results indicate that the proposed combined algorithm is better than the two individual algorithms in predicted result and in real-time capability.Some research and discussion were available in the current literatures, in which the system resource utilization can be improved by adopting efficient call access control scheme. However, this is inadequate. A Dual Dynamic Threshold Guard Channel (DDT-GC) scheme is proposed in this paper, which is targeted at the characters of the multi-service mobile communication system and the shortcoming of the existing access control scheme. By dynamically adjusting the value of both thresholds, the system resource utilization can be improved with a better overall system award. Two-dimensional Markov process traffic models for cellular mobile systems are formulated and analyzed. It is verified by the numerical simulations that the DDT-GC scheme can provide the necessary service guarantee. At the same time, it can decrease the handoff dropping probability and forced termination probability, while improving the system resource utilization.A novel multimedia traffic call admission control algorithm based on call buffer in wireless networks is presented, aiming at different service bandwidth demand of multimedia application, which is characterized by Dual Dynamic Threshold access scheme with Queuing for VBR (DDT-Q). The algorithm gives attention to the variable rate character of none real-time traffic and can adapt its service bandwidth through different settings of the thresholds and the call buffer size. Theoretical performance analysis is made by using three-dimension Markovian chain, and it is also shown that compared with DTR-Q and DTBR algorithm, the performances of the presented algorithm such as average channel utility, call dropping probability and block probability can be improved significantly.By analyzing the routing algorithm in Peer-to-Peer network, the resource searching in the P2P network is always limited in certain local region to avoid broadcast Storm. Therefore, a critical probabilities based on mesh structure P2P network routing protocol is proposed. The algorithm broadcast message by critical probabilities is based on this method. The cover range of the algorithm is proved by using the percolation theory. The proved result shows that the probabilities of searching range cover all the nodes equal to 1 by using the given routing protocol.