Wireless Multicast For Mobile Transparent Computing In WLANs

Mobile transparent computing which combines the transparent computing with mobile Internet has a good market and development potential. Mobile transparent computing terminal, being a handheld mobile device powered by transparent computing system, is a natural fit for the client terminal of the transparent computing system. The terminal uses transparent network operating system (TNOS) as the core of its system, it loads TNOS image from the Internet through wireless network. Due to the bandwidth limitation of wireless network, the users spend a lot of time in loading operating system (OS) and have poor experience performance. Because multicast has efficient transmission strategy, introducing the wireless multicast into the situation may shorten the user’s average system loading time (average waiting time) and improve user’s experience performance.Mobile transparent computing generally uses the wireless local area network (WLAN) or3G network. In this thesis, wireless multicast is used in mobile transparent computing. We propose an efficient multicast grouping mechanism with two levels in mobile transparent computing over WLAN. The first level is the mechanism of multicast grouping based on resource which means dividing the terminals into some groups according to the statistics of resource. Each group asks for the same kind of resource. The second level is the mechanism of multicast grouping based on rate that within each resource group we will continue dividing them into some subgroups to reduce the average waiting time. In addition, this thesis proposes two algorithms which rely on the multicast grouping mechanism. The first one is dynamic programming algorithm for the division of subgroups which can quickly find the optimal grouping scheme. The other one is sorting algorithm for subgroups’ sending order, according to this algorithm we can find the order sent of subgroups with minimum average waiting time.In this thesis, we also present some performance evaluation in mobile transparent computing by using IEEE802.11standard. With our proposal, the user’s average waiting time significantly shorten by using the multicast grouping mechanism compared with using unicast. Besides, it also effectively improves user’s experience performance on mobile transparent computing.