Video transport over mobile ad hoc networks.

详细信息   

• 作者：Asif ; Hafiz Muhammad.
• 学历：Master
• 年：2006
• 毕业院校：King Fahd University of Petroleum and Minerals
• 专业：Engineering, Electronics and Electrical.;Computer Science.
• CBH：1441068
• Country：Saudi Arabia
• 语种：English
• FileSize：5603742
• Pages：142

文摘

Video transport over ad hoc networks is more challenging than over other wireless networks. Wireless links in an ad hoc network are not very error resilient and can go down frequently because of node mobility, interference, channel fading, and the lack of infrastructure. Moreover, typical video applications may need a higher bandwidth and higher reliability connection than that provided by a single link in current or emerging wireless networks, On the other hand, it is possible to establish multiple path between a source and a destination, which provides an extra degree of freedom in designing video transport schemes. Transporting video over wireless networks has two-fold constraints. Not only should it satisfy power minimization issues but QoS parameters should be handled carefully also. In this thesis work, we first study different mobile ad hoc routing protocols. We then analyze the performance of two on-demand routing protocols, Dynamic Source Routing (DSR) and Temporary Ordered Routing Algorithm (TORA), by simulation OPNET (Network Simulation Tool). The focus of the thesis is, however, the analysis of the performance of the Warning Energy Aware Clusterhead (WEAC) protocol for video traffic. In order to have an approximate idea about number of hops, we first run the simulation assuming that a routing protocol is able to set up and constantly update the established paths. We then take an real network scenario (no established path) and establish multihop communication environment. Furthermore, while analyzing the performance of the WEAC protocol for video traffic, we find that the protocol can support upto 2 hops if H.263 (a video compression standard) is used for video data compression and the number of hops reaches 4 when we use H.264 (new video compression standard) with the maximum delay constraint of 250 msec. With the idea that maximum power saving is achieved if the relaying node lies in the middle of source and destination node for HCB model [1], we then calculate the percentage deviation from maximum power saving subject to the actual position of the relaying node which is not in the middle most of the time. Furthermore, we see the effect of sudden demise of cluster heads in the Warning Energy Aware Cluster head (WEAC) protocol. Afterwords, we compare the results when some clusterheads (CHs) have sudden death to the results when there is no switching of CH based on selected performance metrics. We also present the role of power minimization scheme in enhancing WEAC based ad hoc network performance. Thus, we show by simulation how hop count can be increased and how power consumption can be minimized without degradation to video quality by making use of a new video standard, H.264. Finally, we simulate mobile ad hoc network based on the WEAC protocol for H.264 video traffic and then compare these results against those obtained by H.263 standard using several performance metrics. The power minimization issue has been handled by making use of HCB model within the neighbor of a given node.