• The Journal of the Korea Contents Association
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• v.22 no.5
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• pp.26-36
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• 2022

Recently, studies have been conducted to cluster vehicles and disseminate safety messages in a VANET environment for driver safety and smoothy traffic. This paper proposes cluster management scheme for safety message dissemination through V2V communication and V2I communication in a VANET environment with high vehicle density and mobility. The proposed scheme reduces packet loss by selecting CH considering reception quality, total data owned by vehicles, moving speed, and connected vehicles, and maintaining cluster head candidates, which are the main agents of message dissemination, considering frequent cluster departures and subscriptions. In addition, the proposed scheme reduces duplicate messages by utilizing clusters by collaborating with a Road side unit(RSU). To prove the excellence of the proposed scheme, various performance evaluations are performed in terms of message packet loss and the number of RSU processing requests. As a result of performance evaluation, the cluster management scheme proposed in this paper shows better performance than the existing scheme.

• Journal of KIISE:Information Networking
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• v.31 no.2
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• pp.158-170
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• 2004

Mobile IP is a base protocol to support host mobility in IP-based wireless network. It is well known that the protocol contains two main delay factors on a handoff process; one is to detect a host movement, and the other is to register the host's current location to its home network. This paper examines Layer 2(L2) handoff procedure in the IEEE 802.11 Wireless LAN, and identifies these L2 triggers that can be usefully applied to Layer 3(L3) handoff. Then, the MCAA(Multiple-Casting using Anchor Agent) mechanism is proposed. It makes use of the L2 trigger and the network topology to construct an anchor agent dynamically, and the multiple-casting scheme to prevent an ongoing packet to be lost. Using a network simulator, the proposed mechanism has been evaluated the handoff delay and the packet lost point of view, in comparison with the regional registration protocol which is the most well known micro mobility support mechanism.

• Journal of the Korea Society of Computer and Information
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• v.11 no.5 s.43
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• pp.165-173
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• 2006

Network Mobility Basic Support protocol enables mobile network to change their point of attachment to the Internet, but causes some problems such as suboptimal muting and multiple encapsulations. The proposed scheme, combining Prefix Delegation protocol with HMIPv6 concept can provide more effective route optimization and reduce the amount of packet losses and the burden of location registration for handoff. It also uses hierarchical mobile network prefix (HMNP) assignment and provides tree-based routing mechanism to allocate the location address of mobile network nodes (MNNs) and support micro-mobility. In this scheme, Mobility Management Router (MMR) not only maintains the binding informations for all MNNs in nested mobile networks, but also supports binding procedures to reduce the volume of handoff signals oyer the mobile network. The performance is evaluated using NS-2.

• The KIPS Transactions:PartC
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• v.11C no.2
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• pp.213-218
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• 2004

Recently MIP becomes more important for the macro mobility support in the emergence of the global system such as IMT-2000. However this Protocol suffers from many weaknesses on the location management. MIPv4 regional registration is presented for the local registration of MNs. MIPv6 can benefit from the reduced mobility signaling with external networks by employing a local MAP, that is called HMIPv6. The total signaling cost of HMIPv6 is rapidly increased by the number of CNs of an MN when the MN moves around between MAPs. In this paper, we propose a new location management scheme in MIPv6 that reduces the total signaling cost in the location update based on HMIPv6 Here the MN does not send the BU to CNs and HA when it moves around between MAPs. Instead it informs the current location by transferring the modified BU to the previous MAP. According to the results of the performance analysis, we determine the upper bound for the number of forwarding links allowed among adjacent MAPs without the BU information.

• Journal of Convergence Society for SMB
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• v.6 no.4
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• pp.59-64
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• 2016

6LoWPAN (IPv6 over Low Power Wireless Sensor Network) standardized by IETF does not support the mobility of wireless sensor nodes. Since the wireless sensor node, subject to a lot of constraints in the CPU, memory, a battery is not easy to apply to existing protocols such as Mobile IPv6. In this paper, we propose a novel mobility management architecture and methods to work with 6LoWPAN based on the analysis on FPMIPv6 (Fast PMIPv6) the host is not a handover procedure performed in order to support the mobility of such sensor nodes. It was suggested the use of a dispatch code pattern that is not currently used in 6LoWPAN for inter-working, MAG and MAC, MAC in order to reduce packet loss caused as the authentication delay in the handover process to minimize the power consumption of a sensor node that is caused by the re-transmission the new concept of temporary guarantee (temporary guarantee) and trust relationships (trust relationship) between AAA and introduced.

• Journal of KIISE:Computing Practices and Letters
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• v.16 no.6
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• pp.698-701
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• 2010

Recently, Vehicular Networks is being developed to provide variety of services such as email, ftp, and video streaming services. As IP mobility technology, Proxy Mobile IP is developed to provide these services for a VANET user. By adopting Proxy Mobile IPv6 (PMIPv6), Vehicular Networks can support IP mobility, but it may cause a proxy binding update (PBU) message when a vehicle moves from one MAG to another. In addition, if the density of vehicles on the road is high, significant PBU messages are generated. In this paper, we propose bulk PBU message to reduce signaling overhead by those PBU messages when a bunch of vehicles move from one MAG to another. When the vehicles move from one MAG to another, it generates only one bulk PBU message to update those vehicle's location. Through numerical and simulation results, we show that our proposed bulk registration reduces signaling overhead when the density of vehicles and the speed of them are high.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.3B
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• pp.503-516
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• 2010

In this paper, we propose the converged profile and authentication scheme for supporting converged media services of broadcasting & communications convergence in fixed mobile convergence networks. The proposed scheme supports the management of access, service, mobility and IPTV profiles on subscriber and a function of open API(Application Program Interface) for providing the subscriber profile for the third party service provider with the PUSH/PULL method. The open API is based on a web service and a REST(Representational State Transfer) and provides various services for the third party service provider with ease. In addition, the proposed scheme supports a function of SSO(Single Sign-on). After user succeeded in establishing an access connection, user can sustain the same authentication state with this function although connected access network is changed or IMS(IP Multimedia Subsystem) service network is attached. We evaluate and analyze the performance of the proposed scheme through the implementation of CUPS(Converged User Profile Server) system test-bed.

• The Journal of the Korea Contents Association
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• v.4 no.4
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• pp.153-161
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• 2004

An efficient mobility management for mobile stations plays an important role in mobile communication networks. In this paper, we intend to improve the performance of the movement-based location update scheme which is simple to implement and shows good performance. The basic idea used in the proposed location update scheme is to avoid the location update if the mobile subscriber moves around the cell where the last location update was performed. This Is made possible by utilizing the simple movement history information. The performance of the proposed scheme is evaluated and compared with the movement-based location update scheme through simulation. The simulation results show that the proposed location update scheme provides the better performance compared with the movement-based location update scheme by minimizing the unnecessary location updates.

• Journal of Korean Society of Transportation
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• v.35 no.3
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• pp.183-196
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• 2017

In this study, policy evaluation scheme was established to encourage the efficient implementation of EcoMobility which has been expanding gradually all around the world. A total of eight evaluation goals and 22 evaluation items are reviewed and suggested based on the three major evaluation categories of "Basic elements for EcoMobility", "Land use and transport system for EcoMobility", and "Implications and impact of EcoMobility". The results of this study are as follows: the result of AHP analysis which reflects only the hierarchical structure shows a high priority in "Elements for EcoMobility promotion", "Eco-fiendly transport infrastructure", and "Safety in transport". While in result of ANP which considered the elements' dependencies, "Eco-fiendly transport Services", "Welfare in transport", and "Environment by transport" have high weights and importances. In conclusion, this study would be useful to make reasonable judgment based on the analysis results of the two techniques in order to ensure reliability in evaluation of EcoMobility policy. Furthermore we have confirmed appropriate evaluation technique between AHP and ANP which is better to reflect the features of EcoMobility.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.2B
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• pp.210-216
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• 2004

This paper propose a new structure and procedure that provides fast handover for moving users, who are using real-time applications, in next generation IP networks. This paper also show the excellency of proposed scheme with the delay analysis. The analysis shows that the delay of proposed scheme is lower than existing methods, especially in the situation where the delay between MAP and AR is considerable.