• ETRI Journal
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• 제19권3호
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• pp.141-168
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• 1997

The base station (BS) in the CDMA Mobile System (CMS) connects calls through the radio interface and is designed to provide mobile subscribers with high quality service in spite of mobile subscribers motions. The BS consists of multiple base station transceiver subsystems (BTSs), a base station controller (BSC) and a base station manager (BSM). This paper is concerned with the BSC and the BSM. The BSC is located between the BTSs and the mobile switching center (MSC) connected with the public network, and to mobile subscribers via the BTSs. The BSM provides operator-interfaces per the BS and takes responsibility of operation and maintenance (OAM) of the BS. Design of the BSC is based on two module types: functional module and unit module. The functional module is used to support new services easily and the unit module to increase the system capacity economically. Both modular types are easily achieved by inserting the corresponding modules to the system. Particularly, in order to efficiently support the soft handover which is one of CDMA superior advantages, the BSC adopts a large high-speed Packet switch connecting up to 512 BTSs, and thus mobile subscribers can be provided with soft handover in high probability. The BSM is based on a commercial workstation to support OAM functions efficiently and guarantee high reliability of the functions. The BSM uses graphical user interface (GUI) for efficient OAM functions of the BS.

• Journal of KIISE:Information Networking
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• 제35권1호
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• pp.11-20
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• 2008

An inevitable trend in the next generation wireless network environments is coexistence of different wireless access networks in a complementary, manner. In addition, mobile devices equipped with multiple air interfaces simultaneously executing diverse applications have been emerging, In such network environment, It is required that a solution for mobile users to seamlessly roam between different access networks as well as to satisfy QoS requirements of each application by efficiently utilizing coexisting various wireless access networks. In this paper, therefore, we propose a mobility management platform based on per-application end-to-end mobility management and cross-layer handover controls. Four core functional modules composing the proposed platform for end user devices are defined: Monitoring Agents, Profile Database, Decision Engine, and IP Agent. We show through simulations that the presented platform provides an improved QoS as it selectively utilizes the best available networks.

• Journal of Information Processing Systems
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• 제8권4호
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• pp.603-620
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• 2012

Proxy Mobile IPv6 (PMIPv6) is a network-based mobility support protocol and it does not require Mobile Nodes (MNs) to be involved in the mobility support signaling. In the case when multiple interfaces are active in an MN simultaneously, each data flow can be dynamically allocated to and redirected between different access networks to adapt to the dynamically changing network status and to balance the workload. Such a flow redistribution control is called "flow mobility". In the existing PMIPv6-based flow mobility support, although the MN's logical interface can solve the well-known problems of flow mobility in a heterogeneous network, some missing procedures, such as an MN-derived flow handover, make PMIPv6-based flow mobility incomplete. In this paper, an enhanced flow mobility support is proposed for actualizing the flow mobility support in PMIPv6. The proposed scheme is also based on the MN's logical interface, which hides the physical interfaces from the network layer and above. As new functional modules, the flow interface manager is placed at the MN's logical interface and the flow binding manager in the Local Mobility Anchor (LMA) is paired with the MN's flow interface manager. They manage the flow bindings, and select the proper access technology to send packets. In this paper, we provide the complete flow mobility procedures which begin with the following three different triggering cases: the MN's new connection/disconnection, the LMA's decision, and the MN's request. Simulation using the ns-3 network simulator is performed to verify the proposed procedures and we show the network throughput variation caused by the network offload using the proposed procedures.

• Journal of the Institute of Electronics Engineers of Korea TC
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• 제43권8호
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• pp.25-34
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• 2006

In this paper DynaMoNET is suggested as a novel IPv6-based multi-homed mobile network architecture which is composed of nested mobile ad hoc networks dynamically coming together through wireless personal area networks. Each ad hoc network has a mobile router which may work as a root mobile router instead of fixed mobile routers in a DynaMoNET. A root mobile router provides the reliable Internet connectivity for the entire mobile network. This paper includes a innovative handover protocol for multi-homed mobile networks, network switchover algorithm considering multiple decision factors, root mobile router election process based on token-based algorithm fast root mobile router discovery algorithm and fault avoidance mechanism to support reliable Internet connectivity. Finally the system architecture of a mobile router is given in detail.

• Journal of KIISE:Computing Practices and Letters
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• 제15권10호
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• pp.724-739
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• 2009

This paper suggests the energy-efficient message delivery scheme and the software platform which exploits the multiple network interfaces of the mobile terminals and GPS in the current mobile devices. The mobile terminals determine the delivery method among 'direct', 'indirect', and 'WAN' based on the position information of itself and other terminals. 'Direct' method sends a message directly to the target terminal using local RAT. 'Indirect' method extends the service area by exploiting intermediate terminals as relay node. If the target terminal is too far to reach through 'direct' or 'indirect' method, the message is sent using wireless WAN technology. Our proposed scheme exploits the position information and, thus, power consumption is drastically reduced in determining handover time and direction. Network simulation results show that our proposed delivery scheme improves the message transfer efficiency and the handover detection latency. We implemented a message platform in a smart phone realizing the proposed delivery scheme. We compared our platform with other typical message platforms from energy efficiency aspect by observing the real power consumption and applying the mathematical modeling. The comparison results show that our platform requires significantly less power.