• 한국정보통신설비학회:학술대회논문집
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• 2006.08a
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• pp.73-76
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• 2006

International Roaming is a kind of telecommunication service that enables subscribers use the same mobile number when they go abroad and access other service provider's network. International roaming call is made through three network parts-home (original service provider) network, intermediate network, and local (overseas service provider) network. It is not possible to monitor every section of whole roaming service network because service providers do not provide their network management information to other service providers. The limitation causes harsh problem when a service anomaly arises and operators have to confirm the reason of failure. To solve this problem, we propose a scheme that deduces roaming service status of each overseas service provider using internal network management information. SK telecom implemented a international roaming service management system based on the scheme using performance measurement of signaling points, roaming service nodes, and charging data from existing network management systems.

• International Area Studies Review
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• v.18 no.3
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• pp.249-265
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• 2014

The international mobile roaming service has been provided for more than one decade, but high price of international mobile roaming service, which is represented as 'bill shock' is still of major concern in lots of countries including Korea. With understanding of the given price issues, the international organizations, such as OECD, EU, WTO, ITU have been conducting extensive analyses and studies to find suitable solutions and appropriate measures. In the case of EU regulate the international roaming charges and implement the regulation policy. OECD do not have a compelling regulation on roaming charges, but OECD request to member state to find the reasons of high roaming charges and its solution. WTO Council for Trade in Services is reviewing the international mobile roaming in terms of whether impede international trade in services. The purpose of this study is to review many different approaches in international organizations related to reducing international roaming service charges, to drive some regulatory policy directions for reducing roaming charges.

• Proceedings of the Korea Multimedia Society Conference
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• 2003.11a
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• pp.445-448
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• 2003

During a time when cellular systems are being deployed in massive scale worldwide, international roaming is becoming increasingly important. This paper presents UIM (User Identification Module) for mobility support, authentication, and service portability between different mobile systems. We also introduce network model based on PASM(Portable Authentication and Mobility Service Machine) which will support signaling protocol and user information conversions with database for roaming between different mobile networks. Stored data types and elements in UIM, logical data structure and configuration, and registration procedures are described here in the case of DCN (Digital CDMA (Code Division Multiple Access) Network System) and GSM (Global System for Mobile Communications).

• Journal of KIISE:Information Networking
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• v.32 no.5
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• pp.561-573
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• 2005

As the demand on ubiquitous communication increases, global roaming and vertical handover will be prevailing in the near future. Since this environment is accompanied by the frequent handovers at remote sites, a scalable and fast authentication becomes prerequisite for ubiquitous communication. In this paper, we suggest a framework for scalable and fast authentication, using hierarchical caching based on general trust relationship among domains. At the end, we show that the proposed scheme achieves reduced authentication delay and network overhead through an analytic method with fluid flow model.

• International Journal of Advanced Culture Technology
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• v.2 no.1
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• pp.1-13
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• 2014

In next-generation wireless networks, provisioning of IP-based network architecture and seamless transmission services are very important issues for mobile nodes. For this reason, a mobility management mechanism to support global roaming is highly regarded. These technologies bring a broader life by using a global roaming account through the connection of multiple devices or technology to mobile users; they also provide real-time multimedia services. This paper presents a comprehensive performance analysis of fast handover for hierarchical mobile IPv6 (F-HMIPv6), hierarchical mobile IPv6 (HMIPv6), Proxy Mobile IPv6 (PMIPv6), and fast Proxy Mobile IPv6 (FPMIPv6) using the fluid-flow model and random-walk model. As a result, the location update cost of the PMIPv6 and FPMIPv6 is better than that of HMIPv6 and F-HMIPv6. These results suggest that the network-based mobility management technology is superior to the hierarchical mobility management technology in the mobility environment.

• Proceedings of the Korean Information Science Society Conference
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• 1998.10a
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• pp.282-284
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• 1998

차세대 무선 이동통신인 IMT-2000(International Mobile Telecommunication 2000)의 고유 서비스들 중 하나인 글러벌 로밍 서비스는 전 세계의 단일 표준안에 따라서 서로다른 IMT-2000훼밀리 멤버들 간에 로밍을 가능하게 한다는 개념이다. 본 논문에서는 글로벌 로밍의 네트워크 측면의 기능들 중에서 이동성과 밀접한 관련이 있는 위치 정보관리 서비스와 위치 정보 관리 기능을 정의하였다. 본 연구의 결과는 상용화를 앞에 두고 있는 IMT-2000 망의 운용자가 효율적인 글로벌 로밍 서비스를 제공할수 있게 하는 망 관리 수단의 기반이 될 것이다.

• Proceedings of the IEEK Conference
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• 1998.10a
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• pp.39-42
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• 1998

In this paper is design of signal discriminatior system for the third generation mobile telecommunication system (IMT-2000 : International mobile telecommunication service-2000) This system is basically using multiplexing method of CDMA, TDMA and FDMA that this system can be solved third generation systems problems-Frequency bandwidth, international roaming and development new architecture of mobile telecommunication systems. Designed signal discriminator system is perfectly separated three styles multiplexing method signals that more easily, nearly and economically implementation of third generation telecommunication systems. As we develop signal discriminator we will contribute to technical evolution of mobile telecommunication for third generation and stay ahead in the interior technical accumulation in addition to international intercourse as to mobile telecommunication.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.2735-2744
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• 2011

Korean-Automated Guideway Transit (K-AGT) was successfully developed through Light Rail System Development Project. Since then, the domestic development rate of on-board signalling system of light rail has been improved up to 90% by Practical Utilization Project of Light Rail. After utilization project, furthermore, POSCO ICT has developed the wayside signalling system of CBTC, including wireless communication equipment. KRRI carried out the performance test of the wireless communication, interfacing and using the other CBTC equipments of KyungSan Test Line so as to see whether it conforms IEEE 802.11x, international communication standard in view of operational concept of CBTC. In this paper, we presents analysis results of roaming test while train runs.

• International journal of advanced smart convergence
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• v.4 no.1
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• pp.71-87
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• 2015

Mobile users want to be provided with undisrupted network services when they navigate on the Next-Generation (NG) wireless networks. For that, interlocking with a heterogeneous network is important, but there have been few studies on the method for guaranteeing global mobility. Thus, this paper proposes the Proxy-LMA technique, the mobile IP-based global inter-networking system, to enhance global mobility and interoperability within the Next-Generation (NG) network environment. The purpose of the proposed Proxy-LMA system is to expand the boundary of the mobility with regards to the existing mobility management protocol (PMIPv6 and MIPv6) in order to guarantee global mobility and interoperability within the heterogeneous network environment. The results of the performance evaluation showed that the proposed Proxy-LMA system was more efficient than other methods from the standpoint of signaling cost and delay in the heterogeneous network environment.

• International Journal of Computer Science & Network Security
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• v.22 no.3
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• pp.236-244
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• 2022

Network Mobility Basic Support (NEMO BS) protocol has been accredited and approved by Internet Engineering Task Force (IETF) working group for mobility of sub-networks. Trains, aircrafts and buses are three examples of typical applications for this protocol. The NEMO BS protocol was designed to offer Internet access for a group of passengers in a roaming vehicle in an adequate fashion. Furthermore, in NEMO BS protocol, specific gateways referred to Mobile Routers (MRs) are responsible for carrying out the mobility management operations. Unfortunately, the main limitations of this basic solution are pinball suboptimal routing, excessive signaling cost, scalability, packet delivery overhead and handoff latency. In order to tackle shortcomings of triangular routing and Quality of Service (QoS) deterioration, the proposed scheme (Diff-FH NEMO) has previously evolved for end-users in moving network. In this sense, the article focuses on an exhaustive analytic evaluation at Home Agent (HA) entity of the proposed solutions. An investigation has been conducted on the signaling costs to assess the performance of the proposed scheme (Diff-FH NEMO) in comparison with the standard NEMO BS protocol and MIPv6 based Route Optimization (MIRON) scheme. The obtained results demonstrate that, the proposed scheme (Diff-FH NEMO) significantly improves the signaling cost at the HA entity in terms of the subnet residence time, number of mobile nodes, the number of DMRs, the number of LFNs and the number of CNs.