• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.9
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• pp.2243-2250
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• 2014

In wireless sensor networks(WSNs), geographical routing algorithms can enhance the network capacity. However, in real WSNs, it is difficult for each node to know its physical location accurately. Especially, indoor environments contain various obstacles such as concrete wall, furniture which cause non-line-of-sight(NLOS) conditions. To solve the problem, we propose location error compensation algorithm by using two difference topology constructions. First topology is based on mobile node's location which is obtained from anchor nodes. Second topology is based on mutual distance from neighbor nodes. The proposed algorithm efficiently detects and corrects the location errors and significantly enhances the network performance of geographic routing in the presence of location errors.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.8B
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• pp.1105-1114
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• 2010

The Proxy Mobile IPv6 (PMIPv6) has been standardized by the IETF NETLMM WG for network-based mobility management. The PMIPv6 can provide IP mobility for Mobile Nodes (MNs) with low handover latency and less wireless resource usage. But, since the PMIPv6 is basically designed for local mobility management, it cannot support directly global mobility management between different PMIPv6 domains. In the PMIPv6, since all traffic is routed through a Local Mobility Anchor (LMA), it causes a long end-to-end delay and triangular routing problem. Therefore, in this paper, we propose a fast network-based global mobility management scheme and route optimization scheme with a new network entity, called Global Mobility Agent (GMA). Numerical analysis and simulation results show that the proposed scheme is able to support global mobility between different public domains with low handover latency and low end-to-end delay, compared with the PMIPv6.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.5B
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• pp.413-420
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• 2006

HMIPv6 is designed to reduce the signaling load to external network and improve handover speed of MN by including Mobility Anchor Point(MAP) in local handover. However in this case of macro handover, it's just used pervious MIPv6 handover algorithm. So, it occurs packet loss and transmission delay problem. In this paper, we propose the mechanism applying the HMIPv6 for Fast Handover to choose suitable to the condition buffering handover. The condition for the selection is result distance measurement between MN and CN, between MN and NAR. Furthermore, using F-SNOOP protocol, it is possible to improve wireless network performance. Wireless network has high Bit Error Rate(BER) characteristic because of path loss, fading, noise and interference. TCP regards such errors as congestion and starts congestion control. This congestion control makes packet transmission rate low. However, F-SNOOP improves TCP performance based on SNOOP and Freeze TCP that use Zero Window Advertisement(ZWA) message when handoff occurs in wireless network.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.8
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• pp.674-680
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• 2014

In this paper, as one of the fusion of IT and ocean technology, we propose a scheme to support NEMO in a harbor area network to provide network mobility for passengers, distribution as well as give a connection to an MN from an outside network. In a harbor area under PMIPv6 with NEMO support, a problem could be occurred due to overlapping HA/LMA tunnels and duplicate BCE fields. To Solve these problems, we consider the existing mobility option and add an optional field in the PBU message, which can notify the LMA and HA for either an initial connection or handover request. This procedure can reduce some overlapped steps of binding procedure. Hence, our proposed scheme could reduce an amount of delay and save the processing resource in the harbor area under PMIPv6 with NEMO support.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.46 no.6
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• pp.1-10
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• 2009

In a network-based approach such as Proxy Mobile IPv6 (PMIPv6), the serving network controls the mobility management on behalf of a Mobile Node (MN), thereby eliminating a MN from any mobility-related signaling. Although PMIPv6 is being standardized by the IETF NetLMM WG, PMIPv6 still suffers from a lengthy handover latency and the on-the-fly packet loss during a handover. Therefore, this paper presents an enhanced fast handover scheme for PMIPv6. The proposed handover scheme uses the Neighbor Discovery message of IPv6 to reduce the handover latency and packet buffering at the Mobile Access Gateway (MAG) to avoid the on-the-fly packet loss during a handover. In addition, it uses an additional packet buffering at the Local Mobility Anchor (LMA) to solve the packet ordering problem. We evaluate the performance of the proposed handover scheme using both analytical model and simulation. The numerical analysis shows that the proposed scheme has a relatively shorter handover latency. Simulation results demonstrate that the proposed scheme could avoid the on-the-fly packet loss and ensure the packet sequence.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.13 no.5
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• pp.121-133
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• 2013

Defect-free transfer service on the Next-generation wireless network extensive roaming mobile node (MN) to provide efficient mobility management has become very important. MIPv6(Mobility IPv6) is one of mobility management scheme proposed by IETF(Internet Engineering Task Force), and IPv6-based mobility management techniques have been developed in various forms. One of each management techniques, IPv6-based mobility management techniques for PMIPv6 (MIPv6) system to improve the performance of a variety of F-PMIPv6 (Fast Handover for Proxy MIPv6) is proposed. However, the F-PMIPv6 is cannot be excellent than PMIPv6 in all scenarios. Therefor, to select a proper mobility management scheme between PMIPv6 and F-PMIPv6 becomes an interesting issue, for its potenrials in enhancing the capacity and scalability of the system. In this paper, we develop an analytical model to analyze the applicability of PMIPv6 and F-PMIPv6. Based on this model, we design an Secure Smart Mobility Support(SSM) scheme that selects the better alternative between PMIPv6 and F-PMIPv6 for a user according to its changing mobility and service characteristics. When F-PMIPv6 is adopted, SSM chooses the best mobility anchor point and regional size to optimize the system performance. Numerical results illustrate the impact of some key parameters on the applicability of PMIPv6 and F-PMIPv6. Finally, SSM has proven even better result than PMIPv6 and F-PMIPv6.