@misc{oai:ir.soken.ac.jp:00000844,
 author = {李, 蕾 and リ, レイ and LI, Lei},
 month = {2016-02-17, 2016-02-17},
 note = {With the increasing of variable mobile terminals, more and more people desire to access Internet from anywhere, at anytime. However, current mobility support for Internet is insufficient to provide seamless service for real time multimedia traffic. Although there are many research works on the IP mobility enhancement, seamless handover is still big challenge for wireless LAN networks, since only break-before-make handover is supported in WLAN access technology. <br />　Therefore, this thesis is devoted to improve the service performance for the multimedia traffic in wireless LAN networks. Firstly, IP-based networks and the corresponding terminology are introduced in this thesis. Then existing research works for IP-based mobility support are surveyed, and the existing problems to achieve seamless handover in wireless LAN are analyzed thereafter. <br />　This thesis proposes an efficient seamless handover scheme -- Xcast Based Micro-mobility scheme (X&M) for the WLAN road information system. In this proposal, we use explicate multicast (X&M) routing to forward traffic and a new layer-2 trigger to get the information of list of potential access routers respectively. The information of the next potential access routers is need before hand when Xcast routing is applied. However, as in wireless LAN, mobile node cannot communicate with multiple access points at the same time, it is relatively difficult to have the information of the potential access routers for next handover. Therefore, the Service Set Identifier (SSID) of WLAN is used to map the link level information of the neighbor access routers to network level information. Xcast routing can provide the fast path (network layer) re-routing for the mobile node when handover occurs. Meanwhile, different SSIDs are assigned to denote different IP subnets, therefore, we can get the information of the potential access routers by their SSIDs. This solution offers a good method to achieve pro-active handover in wireless LAN. In addition, this new trigger can also be used in any case where the information of new AR is needed in wireless LAN networks. We also present a two-level mobility routing system based on our X&M scheme and IETF network mobility (NEMO) basic protocol to provide large bandwidth for dynamic networks. This system can be applied to the multi-homing networks, in which people may change the wireless access method even though the users do not actually move to new location. Our X&M scheme and NEMO protocol acts as mobility level one. The motion of the node behind mobile network is level two. The overall network architecture is also presented. Besides, an enhancement for mobility level two is proposed to contribute the overall end-to-end seamless handover. Finally, we validated the performance of our solutions by means of simulation, using NS-2, which required important enhancements to the publicly available code. <br />　Our simulations are conducted under different wireless network conditions. First simulation scenario is wireless networks for road communication system. Handover latency and packet loss are focused in order to show the basic performance of our proposal. Our simulation results showed that our proposal can have nearly no handover latency and packet loss compared to other existing handover solutions without using link level information (HMIPv6 in our simulation). Meanwhile our scheme occupies small network bandwidth compared by handover enhancements applied by multicasting routing. Complicate wireless environment is also considered, where multiple wireless channels are available at the same time. Our simulation results show that our scheme can avoid packet mis-ordering problem since mobile traffic is buffered in new access router(as one of the potential access routers) before handover and then the buffered packets are delivered in sequence by new access router in our scheme while packets are received by both old access router and new router respectively in fast handover enhanced HMIPv6 (FHMIPv6) scheme. Also our proposal has no packet loss, while FHMIPv6 scheme suffers with packet loss, since the slow establishment of the tunnel between old access router and new access router when handover happens too often. Simulations have also been conduct for two-level mobility. After analysis of the handover latency and packet loss performance, we conclude from the simulation that our proposed fast handover scheme can avoid traffic interruption by shortening the movement detection. <br />　Finally, an abstract model of mobility framework is defined. The existing approaches can be denoted by one or several mobility frameworks. By the analysis of this model, we can classify the existing schemes easily and achieve better understanding of their merits and drawbacks, as well as our proposal., application/pdf, 総研大甲第906号},
 title = {Fast Handover using Explicit Multicast for IPv6-based Wireless LAN Networks},
 year = {}
}