• Proceedings of the Korea Information Processing Society Conference
• /
• 2009.11a
• /
• pp.547-548
• /
• 2009

The development of USN(Ubiquitous Sensor Network) technology is creating numerous application areas. Although a network configuration with fixed sensors was the norm in the past, the coexistence of mobile and fixed sensor nodes is a new trend. Fixed sensor networks focused on the energy efficiency of nodes, but the latest studies consider guaranteeing the mobility of nodes and maintaining their connectivity, while remaining energy efficient at the same time. This paper proposes a routing protocol for a mobile ad-hoc sensor network that improves the mobility, connectivity and energy efficiency of nodes while allowing for the management and maintenance of a large number of nodes even in a complex communication environment where mobile and fixed nodes coexist. An algorithm for multi-hop multi-paths, a technique for topology reconfiguration by node movement prediction and vibration sensors, path setting for a large number of nodes, and efficient data transfer technology have been introduced to implement the modified LEAHC-AOMDV protocol. Furthermore, the excellence of this protocol was verified through a comparative experiment with the conventional LEACH protocol.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2008.11a
• /
• pp.1001-1003
• /
• 2008

유비쿼터스 환경을 위해 개별 서비스의 집합으로 정의할 수 있는 컴퓨팅 환경의 이동을 필요로 하고 있다. 이러한 컴퓨팅 환경의 이동을 지원하기 위해 텍스트 기반으로 확장성이 좋고 이동성에도 유용한 SIP 을 이용하였다. 확장된 SIP 을 이용하여 컴퓨팅 환경의 이동을 관리하는 프로토콜을 제안하였다.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.36 no.6B
• /
• pp.608-617
• /
• 2011

ubiquitous network management system (u-NMS) is the network management system based on smartphone which are recently of wide use. The purpose of the u-NMS is to provide convenience for network administrator utilizing the mobility of smartphone and to manage the network efficiently. This paper proposes the smart NMS agent and the mobility management server (MMS). The smart NMS agent enables to use the monitoring web server and remote control application on the smartphone in wireless network. The MMS is developed to reduce the problems such as handover latency and packet loss, which can be taken place in wireless network. The network manager can monitor traffic in real time through the smart NMS agent and remotely control the network efficiently when sudden failures happen in the u-NMS. In this paper, performance evaluation is carried out with our test-bed system implemented. We focus on the measurement of the MMS performance. When the MMS is compared to previous mobility management protocol, our mobility management server reduces the average latency up to 65% in initial access, handover latency and processing delay to the network management center.

• Journal of Korea Society of Digital Industry and Information Management
• /
• v.5 no.3
• /
• pp.107-115
• /
• 2009

Traditionally, simulation method is used to test and evaluate the performance of communication protocol or functional elements for mobile communication service. In this paper, wireless network simulator is implemented using the C++ object-oriented programming language. This simulator can simulate wireless data services, like as ad-hoc networks, by considering the user's mobility. In this paper, the simulator includes network traffic model to reflect wireless data service and traffic source model to represent a user's mobility similar to real service environment and traffic characteristics can be reflected on the simulation, and also more accurate simulation results can be got through that. In addition, by using object-oriented techniques, new service feature or environment can be easily added or changed so that the developed mobile communication simulator can reflect the real service environment all the time. This simulator can be used in adjusting the characteristics of wireless data hosts following the mobility of the user, and also can be used in building new wireless ad-hoc network routing protocols.

• The KIPS Transactions:PartC
• /
• v.17C no.3
• /
• pp.243-250
• /
• 2010

Vehicular communication networking is one of the most important building blocks of Intelligent Transportation System (ITS). The vehicular communication network is a wireless communication system enabling vehicles to communicate with each other as well as with roadside base stations. Mobility management of vehicles which move at high speeds and occasionally make a long journey is an interesting research area of vehicular communication networks. Recently, The Proxy Mobile IPv6 (PMIPv6) protocol is proposed for network-based mobility management to reduce the overhead of mobile nodes. PMIPv6 shifts the burden of the mobility management from mobile nodes to network agents to decrease the overhead and latency for the mobility management. In this paper, we derive the scenario of deploying PMIPv6 in vehicular communication networks and propose a new LMA handover mechanism for realizing the scenario. By carrying out the ns-2 based simulations, we verify the operability of the proposed mechanism.

• The KIPS Transactions:PartC
• /
• v.13C no.4 s.107
• /
• pp.461-470
• /
• 2006

Recently mobile Stream Control Transmission Protocol (mSCTP) has been proposed as a transport layer approach for supporting mobility. When a mobile terminal (MT) is not located in the home network. a terminal that wishes to communicate with the MT is not able to establish mSCTP association to the MT, since mSCTP does not include the location management mechanism. In order to solve this problem. an interworking approach using the Session Initiation Protocol (SIP) INVITE method has been proposed. However, this approach has shown subsequent delay in acquiring the current location information of the MT when initiating mSCTP association establishment. In this paper, we propose new SIP methods and an approach that minimizes the address acquisition delay (AAD) by utilizing those SIP methods. Mathematical analysis and simulation results show that the proposed approach is more efficient than the previous approach in terms of AAD in all kinds of SIP environments.

• Journal of the Institute of Convergence Signal Processing
• /
• v.18 no.1
• /
• pp.6-12
• /
• 2017

In this paper, we proposed IoT based Smart Health Service using Motion Recognition for Human UX/UI. Until now, sensor networks using M2M-based u-healthcare are using non-IP protocol instead of TCP / IP protocol. However, in order to increase the service utilization and facilitate the management of the IoT-based sensor network, many sensors are required to be connected to the Internet. Therefore, IoT-based smart health service is designed considering network mobility because it is necessary to communicate not only the data measured by sensors but also the Internet. In addition, IoT-based smart health service developed smart health service for motion detection as well as bio information unlike existing healthcare platform. WBAN communications used in u-healthcare typically consist of many networked devices and gateways. The method proposed in this paper can easily cope with dynamic changes even in a wireless environment by using a technology supporting mobility between WBAN sensor nodes, and systematic management is performed through detection of a user's motion.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2007.10a
• /
• pp.49-53
• /
• 2007

The Next generation IP-based wireless access network proposed Mobile IP(IPv4) protocols to support mobility of node. Because Mobile IPv4 operates on th basis deigned IP in fixed network, it causes performance drop like triangle routing and handover delay. Therefore Mobile IPv4 needs scheme to complement this problems and to support service guaranteed QoS. Concerns about using MPLS networks in the next generation IP-based wireless access network are increasing. In our previous research, we proposed MCS&MUMCA, IP mobility management scheme. In this paper, we linkage the MCS&MUMCA in MPLS network and analyze its the performance.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.38B no.6
• /
• pp.454-472
• /
• 2013

The development of wireless network technology and the increasing use of wireless networks to mobile users with a variety of wireless network systems has arisen. Wireless sensor networks, they can be nested together, and the need to switch between the network, depending on your needs. Next Generation Wireless Networks(NGWN) gives the mobile user a wide coverage and optimized service etc. Previous hand off management protocol is not enough to secure support of the NGWN application program. Cross-layer Handoff(CLH) protocol technique has been developed to support between and inside networks of handoff management of NGWN. CLH supports mobility management in a wireless network environment and also utilizes mobility speed and handoff signaling delay information to improve the handoff performance ability. For the analysis of handoff performance ability, we analyzed sensitivity of link layer and network layer, therefore, CLH technique is suggested based on this analysis.

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