• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.1059-1062
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• 2005

A hybrid ad-hoc network consists of a wired network and a mobile ad-hoc network connected by the internet gateway. To provide seamless service for internet user in hybrid ad-hoc network, an efficient internet gateway selection technique and a fast handover technique are needed. In this paper, we propose a seamless handoff technique for providing mobility of mobile hosts in hybrid ad-hoc networks. The proposed technique improves general handoff performance by an internet gateway re-registration algorithm for ad-hoc networks. Moreover, it reduces handoff processing time in the range of certain region by using mobility management agent (MMA) and also the packet loss when handoff occurs out of the range of MMA by tunneling technique.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.34S no.2
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• pp.11-20
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• 1997

It is a recent trend that mobile communications and PCS are intergrated into the broadband network. Broadband mutlimedia traffic will be transported over the integrated network. In this paper, we propose a connection re-routing method for fast inter-switch hadoffs and dynamic resurce reservation scheme, which is based on the proposed re-routing method, for the ATM-based personal communications network. To reduce the delay for re-routing method, for the ATM-based personal communications network. To reduce the delay for re-routing, the proposed re-routing method is to reserve VPI/VCIs for possible inter-swich handoff calls in advance. Our reservation scheme is to statistically reserve the fixed resources for possible inter-switch handoff calls, according to the QoS of the handoff calls. The simmulation reslts show that our proposed scheme satisfies the required QoS of handoff calls and keep the dropping probability of handoff calls lower than other schemes.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2006.05a
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• pp.505-509
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• 2006

Recently, wireless Internet service has become generalized, and required the user authentication of a mobile hosts and QoS. However, time required for user authentication during handoff Processes between a wireless LAN system and mobile hosts is long, and is unsuitable for real-time communication and multimedia applications. In this paper. we improved the existing system in order to reduce a lead time of user authentication as they extended a Fast Inter-AP handoff. We use a Mechanism to assume a confidence degree with bases by the time that stayed at individual wireless LAN systems in order to reduce the handoffs. The experiment network shows that it decreases communication load, and improves communication QoS.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.7A
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• pp.746-754
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• 2007

In this paper, we propose a fast handoff algorithm for micromobility management enhancement in HMIPv6 networks, which eliminates the DAD procedure involved in the regular HMIPv6 in order to o decrease handoff latency and increase the resource utilization efficiency. In the proposed scheme, the MAP is designed to guarantee the uniqueness of MN's interface identifier within a MAP domain as long as the MN moves in a MAP domain, so that the MN configures the new address without the DAD procedure resulting in the decreased handoff latency significantly When the MN resides in a subnet, MIPv6 is used adaptively as a mobility management protocol, which is to reduce bandwidth waste from the IP packet header overhead of IP-in-IP tunneling from the regular HMIPv6. We evaluate the performance of the proposed handoff micromobility algorithm in terms of handoff delay and packet loss thru computer simulation. Thru various computer simulation results, we verified the superior performance of the proposed scheme by comparing with the results of other schemes, MIPv6 and HMIPv6.

• KIPS Transactions on Computer and Communication Systems
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• v.2 no.6
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• pp.265-278
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• 2013

With the recent advancements in various wireless communication technologies, the importance of mobile multicasting is coming to the fore, in an effort to use network resources more efficiently. In the past, when various mobile IP-based multicast techniques were proposed, the focus was put on the costs needed for network delivery for providing multicast services, as well as on minimizing the multicast handover delay. For techniques using MIPv6 (Mobile IPv6), a host-based mobility management protocol, however, it is fundamentally difficult to resolve the problems of handover delay and tunnel convergence. To resolve these problems, a network-based mobility management protocol called PMIPv6 (Proxy Mobile IPv6) was standardized. Although performance is improved in PMIPv6 over MIPv6, it still suffers from the problems of handover delay and tunnel convergence. In this paper, to overcome these limitations, a technique called LFH (Low-cost and Fast Handoff) is proposed for fast and low-cost mobility management with multicasting support in PMIPv6 networks. To reduce the interactions between the complex multicast routing protocol and the multicast messages, a simplified proxy method called MLD (Multicast Listener Discovery) is implemented and modified. Furthermore, a TCR (Tunnel Combination and Reconstruction) algorithm was used in the multicast handover procedure within the LMA (Local Mobility Anchor) domain, as well as in the multicast handover procedure between domains, in order to overcome the problem of tunnel convergence. As a result, it was found that LFH has reduced multicast delay compared to other types of multicast techniques, and that it requires lower costs as well.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.2A
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• pp.128-139
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• 2004

As the Internet usage grows, people want to access the Internet while they are moving. To satisfy this requirement economically, IEEE 802.11 Wireless LANs(WLANs) are rapidly deployed. In order to support mobility, WLANs must provide smooth handoff mechanism. Recent studies show, however, handoff delay of WLANs exceeds 300ms, most of which is due to slow scanning mechanism finding a new AP. With this handoff delay, current WLANs is not suitable to provide seamless realtime interactive services such as VoIP sevice. In this paper, we analyze the current handoff method of IEEE 802.11 and we propose a new handoff algorithm which can decrease time needed for searching a new AP and thus reduce overall handoff time. We show by simulation that the proposed algorithm has shorter handoff delay than current handoff method.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.19 no.6
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• pp.93-103
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• 2009

Recently, there is an increase in demand of real-time multimedia service in the WLAN environment, with a commercialization of IEEE 802.11n standard. However, the 802.1x authentication protocol is too slow to provide seamless real-time multimedia service, which defined in an IEEE 802.11i security standard. In this paper, a Ticket-based authentication mechanism in the CAPWAP(Control And Provisioning Wireless Access Point) architecture is introduced to support for the fast handoff.

• Journal of Communications and Networks
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• v.12 no.5
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• pp.480-491
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• 2010

Along with the wide acceptance of IEEE 802.11 wireless local area network (WLAN), new applications such as Internet protocol (IP) telephony over WLAN are fast emerging today. For battery-powered IP phone devices, the life time extension is a key concern for the market acceptance while today's 802.11 is not optimized for snch an operation. In this paper, we propose a novel idle mode operation, which comprises paging, idle handoff, and delayed handoff. Under the idle mode operation, a mobile host(MH) without any active session does not need to perform handoff within a predefined paging area (PA). Only when it enters a new PA, an idle handoff is performed. The proposed idle mode allows an MH without traffic to extend its life time. We develop a new analytical model in order to comparatively evaluate our proposed scheme. The numerical resnlts demonstrate that the proposed scheme outperforms the existing schemes with respect to power consumption.

• Proceedings of the IEEK Conference
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• 2001.06a
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• pp.341-344
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• 2001

H.323 proposes to use Mobile IP and H.323 ad hoc conference signaling to provide Handoff function to an H.323 mobile terminal. But the H.323 ad hoc conference signaling has a drawback. It requires an H.323 terminal to do a complex conference signaling which takes a longer signaling time. In this paper, we propose an GK architecture that provides Handoff function effectively using 3$^{rd}$ P'||'||'||'||'||'&'||'||'||'||'||'R(Third party initiated Pause and Rerouting) signaling which are done through H.245 logical channel. The GK which is implementing 3$^{rd}$ P'||'||'||'||'||'&'||'||'||'||'||'R signaling only requires an H.323 endpoint to do the H.323 basic signaling in reestablishing media channel and gives the faster Handoff signaling. To do this, our GK has derived H.245 control channel using tunneling f3r all H.323 calls including the fast connect calls which enable terminals communicate each other if they doesn't have H.245 control channel .municate each other if they doesn't have H.245 control channel .

• The KIPS Transactions:PartC
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• v.8C no.6
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• pp.821-830
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• 2001

H.323 proposes to use Mobile IP and H.323 ad hoc conference signaling to provide Handoff function to a mobile terminal. But H.323 ad hoc conference signaling has a drawback. It requires an H.323 endpoint to do a complex conference signaling which makes inter-operability between H.323 endpoints difficult and takes the longer signaling time. In this paper, we propose an Handoff signaling using H.323 rerouting(Third party initiated Pause and Rerouting). H.323 rerouting signaling only requires an H.323 endpoint to do H.323 basic signaling in reestablishing media channel, and makes inter-operability more easier and provides the faster Handoff. To do this, our H.323 GK has derived H.245 control channel using tunneling for all H.323 calls including the fast connect calls which enable endpoints communicate each other if they don\`t have H.245 control channel. In order to evaluate the performance of the proposed signaling, we have conducted an experiment that compares a call transfer signaling using H.323 rerouting with ad hoc conference signaling in inter-operability and signaling delay. The results of our experiment shows that the call transfer signaling can inter-operate with four H.323 endpoints among five H.323 endpoints of other vendors and reduces the signaling delay average 1.4 sec.