| Summary: | 碩士 === 國立東華大學 === 電子工程研究所 === 97 === In the trend of future vehicular environment, mobile devices may need to cross over different servicing location of BS. At the same time, in order to maintain the network services, it's necessary to study on the integration of different networks, and how to integrate all the network technologies such as WiFi, WiMAX, and 3G, that is the key point. The vehicular user can have a roaming in different types of wireless communication technologies, handover in the duration of exchanging different networks, and providing the better continuous connections of application services in the environment of different networks. In this study, we aim at applying the main feature of NGN (Next Generation Network) to the vehicular network, and using IEEE 802.21 MIH standard to integrate different networks in the same platform.
On the other hand, in the advanced development of every multimedia services, the needs of network bandwidth for vehicular user is increasing, and approaches to be better and high quality. In order to satisfy users’ high quality requirements, it is necessary to supply a QoS mechanism in such a heterogeneous wireless network environment. Especially for real-time services, it requires a high quality of guaranteed service. This study proposed an adaptive QoS management mechanism to aim at the concerned QoS parameters of different applications. Besides, with the environment of IEEE 802.21 MIH network, it can obtain the parameters of received signal strength to supply the best option of available networks in current accessible wireless networks. By means of above, it can achieve the purpose of high QoS so that the applications can fit most needs.
In the simulation results, the proposed Management Module in this thesis spend much handover time by about 46.13% than the homogeneous network, but the throughput of the proposed Management Module is higher by about 27.1% than the homogeneous network. With the adaptive QoS management mechanism, the different real-time applications have successful performance improvement. The simulation results indicate that the proposed mechanism decreases jitter about 0.0787 milliseconds for VoIP (Voice over IP) and decreases 3.39% packet loss ratio for high definition video stream.
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