• Journal of Industrial Technology
• /
• v.28 no.B
• /
• pp.245-250
• /
• 2008

Recently, mobile devices have supported wireless LAN as well as bluetooth, where the services such as heterogeneous network access and seamless mobility connection are important. Even though the mobility and physical network might be varied, an efficient communication mechanism for the network access and a robust mobility management of mobile devices are needed. In this paper, we design and implement a Bluetooth system with mobile LAN access capability. The proposed system has the following features; 1) IP connection is enabled by BENP in the link layer, 2) The networks devices of heterogeneous mobile devices are integrated into a single virtual network interface, 3) IP mobility between the bluetooth and wireless LAN is supported by mobile IP. The experimented results show that the packet loss and delay time during the handover duration is reduced by predicting the handover among different networks followed by the setup of any required parameters in advance.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.43 no.11 s.353
• /
• pp.25-34
• /
• 2006

In this paper, we propose the new Cellular Ethernet System that supports faster handovers than IP layer handover scheme for WiBro Networks and analyze the performance of the proposed scheme. In WiBro Networks, it is very important for service providers that supports fast handovers for mobile users who want superior service. But in case of Mobile IPv6, which supports IP layer handovers, there exists very long latency for detecting movement and duplicated IP address. And besides, handovers in wired area must be carried out after completing handovers in wireless area. So, Mobile IPv6 cannot provide superior service to mobile users. To remedy these problems, we here propose the new Cellular Ethernet System that consists of MAC layer bridges for WiBro Networks and analyze the performance of Cellular Ethernet System handover scheme and show that it has better performance than Mobile IPv6.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.36 no.10B
• /
• pp.1182-1191
• /
• 2011

In this paper, we propose a network-based IP mobility management scheme, called Access Independent Mobile Service with IPv4/IPv6 Dual Stack (AIMS-DS), which can provide high-quality multimedia services to IPv4/IPv6 dual-stack mobile nodes (MNs) without any interruption over various wireless/wired access networks. The proposed scheme provides an MN with a fast and reliable mobility service among heterogeneous wireless access networks through the network-based control, the complete separation method of control and data plane, the cross-layer (layer2 and layer3) interworking method for handover control acceleration, etc, In addition, the proposed AIMS-DS can provide seamless mobility service to an MN under the environments of IPv4/IPv6 coexisting networks through the home address mobility support and transport network support. Through performance evaluation with computer simulations, we have shown the superiority of the proposed AIMS-DS in terms of handover latency, packet 1085 and packet delivery latency.

• The KIPS Transactions:PartC
• /
• v.14C no.2
• /
• pp.163-170
• /
• 2007

The next generation communication environment consists of various wireless access networks with distinct features that are configured as an overlay topology. In the network environments, the frequency of hand overs should be minimized and the error propagation should be solved in order to provide high-quality multimedia services to mobile users. Therefore, we propose an performance enhancement approach, based on mSCTP, that provides high quality multimedia services to mobile users by ameliorating the error propagation problem. We utilizes the following four functions: 1) the separation of transmission paths according to the types of frames. 2) retransmission strategy to minimize the loss rate of frames, 3) Foced vertical handover execution by utilizing bicasting, 4) using the stability period in order to reduce the effect of the ping pong phenomenon. The simulation results show that the proposed approach provides seamless multimedia service to mobile users by achieving error resilience.

• Journal of KIISE:Information Networking
• /
• v.35 no.3
• /
• pp.183-191
• /
• 2008

In this paper, we propose Stream Control Transmission Protocol(SCTP) proxy which supports making an SCTP connection from a Corresponding Node(CN) to a Mobile Node(MN). Recently, mobility support in transport layer is proposed, which provides mobility in end-to-end way using the extension of SCTP. Mobile SCTP can provide handover to all applications that use SCTP as a transport protocol. However, current SCTP does not include independent location management service and can not make connection from a CN to a MN without assistance of other mobile protocols. To solve this problem, Proposed SCTP proxy interoperates with generic location management service and performs an address transformation to forward connection set up messages to the MN. Using the proposed proxy, SCTP can provide a complete mobility support including a connection setup to the MN and maintaining an existing connection.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.41 no.6
• /
• pp.652-662
• /
• 2016

This paper proposes a user mobility management scheme which supports seamless service even if a user changes his accessing terminal in service in IP-based convergence network. Most of ongoing researches concerning mobility management as well as the existing mobility schemes have been focused to support terminal mobility. It is limited to support a variety of mobility types such as user mobility. The proposed scheme uses the mapping relationship between UID(User Identifier), user specific identifier and TID(Terminal Identifier), specific terminal identifier and forms packet address with user specific permanent 3 layer address for session continuity in case of user mobility. We numerically analyze and compare handover signaling cost between the existing user mobility scheme and the proposed scheme. The result shows that the proposed scheme has lower handover signaling cost than the existing one, [1].

• Journal of Digital Convergence
• /
• v.11 no.3
• /
• pp.279-284
• /
• 2013

Wireless access network section needs strong security which supports high data rate and mobility not to invade patient's privacy by exposing patient's sensitive biometric from automatic implantable device that is adapted to u-healthcare service. This paper builds test bed and performs assessment and measurement of security ability of WiMAX network to transmit and receive mobile patient's biometric by building WiMAX network in wireless access network not to expose paitne's biometirc at wireless access network section to the third person. Specially, this paper compares and assesses data security, MAC control message security, handover conection delay, and frame loss and bandwidth of ECDH at the layer of WiMAX security compliance, WiMAX MAC IPSec, and MAC.

• Journal of KIISE:Information Networking
• /
• v.29 no.3
• /
• pp.299-313
• /
• 2002

Recently, the demand for mobile communications and multimedia services has rapidly increased so that conventional cellular system cannot fulfill the requirement of users (capacity and QoS) any more. Therefore, the hierarchical cellular system has been suggested in order to guarantee the QoS and to admit large population of users. IMT-2000 adopts the hierarchical cellular structure, which requires a call control algorithm capable of manipulating and utilizing the complicated structure of hierarchical cellular structure with handiness and efficiency. In this thesis, as an improvement of conventional combined algorithm, a new call control algorithm considering the moving speed of terminal and bandwidth is suggested. This algorithm employs buffers and guard channels to reduce the failure rate. Also, this algorithm considers the moving speed of terminal and bandwidth to elevate the efficiency. Furthermore, calls are handled separately according to the moving speeds of terminal and bandwidths to improve the QoS and reduce the handover rate. As an evaluation of the suggested algorithm, a model hierarchical cellular system is constructed and simulations are conducted with various types of traffic. As the result of the simulations, such indices as block rate, drop rate, channel utilization, and the number of inter layer handovers are examined to demonstrate the excellency fo the suggested algorithm.

• KIPS Transactions on Computer and Communication Systems
• /
• v.1 no.3
• /
• pp.205-218
• /
• 2012

Mobility management of the mobile nodes and provision of seamless handover is crucial to an efficient support for the global roaming of the mobile nodes in next-generation wireless networks. Mobile IPv6 and mobility management in extended IP layer, which highly depend on traffic characteristics and user mobility models, were proposed by the IETF. Therefore, to evaluate the in-depth performance about these factors is important. Generally, the performance of IPv6-based mobility management protocol is evaluated through simulation. This paper shows the correlation between network parameters and performance metrics through numerical results, which is investigated how influence handoff latency and packet loss. And this paper uses mathematical analysis of the system parameters, such as the subnet residence time, the packet arrival rate and delay in wireless connection through the analytical framework which evaluate the performance of IPv6-based mobility management protocol.

• Journal of Information Processing Systems
• /
• v.8 no.4
• /
• pp.603-620
• /
• 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.