• Title/Summary/Keyword: Seamless Connectivity

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Seamless Routing and Cooperative Localization of Multiple Mobile Robots for Search and Rescue Application

  • Lee, Chang-Eun;Im, Hyun-Ja;Lim, Jeong-Min;Cho, Young-Jo;Sung, Tae-Kyung
    • ETRI Journal
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    • v.37 no.2
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    • pp.262-272
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    • 2015
  • In particular, for a practical mobile robot team to perform such a task as that of carrying out a search and rescue mission in a disaster area, the network connectivity and localization have to be guaranteed even in an environment where the network infrastructure is destroyed or a Global Positioning System is unavailable. This paper proposes the new collective intelligence network management architecture of multiple mobile robots supporting seamless network connectivity and cooperative localization. The proposed architecture includes a resource manager that makes the robots move around and not disconnect from the network link by considering the strength of the network signal and link quality. The location manager in the architecture supports localizing robots seamlessly by finding the relative locations of the robots as they move from a global outdoor environment to a local indoor position. The proposed schemes assuring network connectivity and localization were validated through numerical simulations and applied to a search and rescue robot team.

Density-Based Opportunistic Broadcasting Protocol for Emergency Situations in V2X Networks

  • Park, Hyunhee;Singh, Kamal Deep;Piamrat, Kandaraj
    • Journal of information and communication convergence engineering
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    • v.12 no.1
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    • pp.26-32
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    • 2014
  • Vehicular-to-anything (V2X) technology is attractive for wireless vehicular ad-hoc networks (VANETs) because it allows for opportunistic choice of a vehicular protocol between vehicular-to-vehicular (V2V) and vehicular-to-infrastructure (V2I) communications. In particular, achieving seamless connectivity in a VANET with nearby network infrastructure is challenging. In this paper, we propose a density-based opportunistic broadcasting (DOB) protocol, in which opportunistic connectivity is carried out by using the nearby infrastructure and opposite vehicles for solving the problems of disconnection and long end-to-end delay times. The performance evaluation results indicate that the proposed DOB protocol outperforms the considered comparative conventional schemes, i.e., the shortest path protocol and standard mobile WiMAX, in terms of the average end-to-end delay, packet delivery ratio, handover latency, and number of lost packets.

Concord: A Proactive Lightweight Middleware to Enable Seamless Connectivity in a Pervasive Environment

  • Hsu Sam;Mutha Mahesh;Pandya A.S.;Lho Young-Uhg
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.5 no.3
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    • pp.189-195
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    • 2005
  • One of the major components of any pervasive system is its proactive behavior. Various models have been developed to provide system wide changes which would enable proactive behavior. A major drawback of these approaches is that they do not address the need to make use of existing applications without modifying the applications. To overcome this drawback, a middleware architecture called 'Concord' is proposed. Concord is based on a simple model which consists of Lookup Server and Database. The rewards for this simple model are many. First, Concord uses the existing computing infrastructure. Second, Concord standardizes the interfaces for all services and platforms. Third, new services can be added dynamically without any need for reconfiguration. Finally, Concord consists of Database that can maintain and publish the active set of available resources. Thus Concord provides a solid system for integration of various entities to provide seamless connectivity and enable proactive behavior.

Seamless Mobile Learning: Possibilities and Challenges Arising from the Singapore Experience

  • SO, Hyo-Jeong;KIM, Insu;LOOI, Chee-Kit
    • Educational Technology International
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    • v.9 no.2
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    • pp.97-121
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    • 2008
  • The purposes of the present study are to describe the design of mobile learning scenarios based on learning sciences theories, and to discuss implications for the future research in this area. To move beyond mere speculations about the abundant possibilities of mobile learning and to make real impact in K-12 school settings, it is critical to conduct school-based research grounded on the learning sciences theories. Towards this end, this paper describes school-based mobile learning projects conducted by a research team at the Learning Sciences Lab in Singapore, and then discusses the possibilities and challenges of mobile learning to further inform future research. Specifically, this paper explores the affordances of mobile technology, such as portability, connectivity and context-sensitivity, to design seamless learning scenarios that bridge formal and informal learning experiences. The authors present a framework for re-conceptualizing different types of learning based on physical settings and intentionality, and then describe two seamless learning scenarios, namely 3Rs and Chinatown Trail, which were implemented in one primary school in Singapore. In conclusion, the authors discuss the affordances of seamless mobile learning for enhancing one's lived experiences to build a living ecological relationship between the person and the environment, and how mobile technology can play a critical role for enabling such lived experiences.

Design and Implementation of Interworking Architecture between 3G Cellular Network and Wireless Broadband Network (이동통신망과 WiBro망과의 연동을 위한 네트워크 아키텍처와 구현방안)

  • Woo Dae-Sic;Park Seong-Soo;Lee Dong-Hahk;Yu Jae-Hwang;Ihm Jong-Tae
    • 한국정보통신설비학회:학술대회논문집
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    • 2006.08a
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    • pp.47-52
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    • 2006
  • In this paper, we suggested new network architecture to provide seamless service between the cellular system and new wireless broadband network such as IEEE 802.16e, called WiBro. The interworking technologies are very important issue because mobile operator should provide service connectivity between various wireless networks based on different access technologies. Moreover a change and modification on legacy network should be minimized for providing interworking with new wireless broad-band network. We implemented proposed interworking architecture between 3G cellular network and 802.16e network to provide seamless service including interworking unit in real test environment. Also, we performed performance evaluation in hybrid network environments.

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A Study on Common Interface providing among Heterogeneous Terminal in Ubiquitous (유비쿼터스 환경에서 이기종 단말기 간의 공통 인터페이스 제공에 관한 연구)

  • Park, Jung-Yeon
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 2006.11a
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    • pp.391-394
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    • 2006
  • This paper deals with the method will be able to support a common interface softly for the different with each other operating system users in next generation ubiquitous network. To controls in proxy servers that data portion be able to use commonly such as each different instruction, metaphor, image based on operating system, icons, it will be able to increases the efficiency of bandwidth use and minimizes a duplication transmission data from inside the bandwidth which is limited. Also it will be able to do method of common user interface provision to support seamless connectivity with each different network devices in the next generation.

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A study for efficient Media Independent Handover in environment of IEEE 802.11 wireless network interface (IEEE 802.11 무선 네트워크 인터페이스 환경에서 효율적인 개체무관 핸드오버를 위한 연구)

  • Choi, Ji-Hoon;Kim, Dong-Il
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2008.10a
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    • pp.66-69
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    • 2008
  • As a mobility support for IP have studied, Internet Engineering Task Force(ITEF) standardized the mobile IPv6 protocol. When a mobile node moves between networks, MIPv6 maintains connectivity to network and supports seamless communication, and these processes are called a Handover. IEEE 802.21 standardized MIH(Media Independent Handover) for seamless Handover. MIH used three services for Handover between low layer and upper layer. In this paper, we designed two modes on existing MIH for seamless Handover. We implemented a dual-interface mobile host(MH) model in network simulation2 (ns2) to evaluate how it performs in comparison with single-interface MH.

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Secure Pre-authentication Schemes for Fast Handoff in Proxy Mobile IPv6

  • Baek, Jaejong
    • Journal of information and communication convergence engineering
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    • v.14 no.2
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    • pp.89-96
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    • 2016
  • In mobile communication, there are various types of handoff for the support of all forms of mobility. Proxy mobile IPv6 (PMIPv6) enables local network-based mobility management of a mobile node without any effect of mobility-related signaling. Recently, PMIPv6 has been considered for supporting mobility management in LTE/SAE-based mobile networks. To support seamless mobility in heterogeneous mobile networks, the overall cost of handoffs needs to be minimized and the procedure should be guaranteed to be secure. However, the reduction of the authentication cost has not been fully investigated to provide seamless connectivity when mobile users perform a handoff between the PMIPv6 domains. This paper proposes secure pre-authentication schemes, completing an authentication procedure before performing a handoff, for a fast handoff in PMIPv6. Analytic models have been used for measuring the authentication latency and for the overhead cost analysis. In addition to providing fast authentication, the proposed pre-authentication schemes can prevent threats such as replay attacks and key exposure.

A Simple Path Prediction Scheme to Improve Handoff Efficiency in All-IP Wireless Networks

  • Zhu, Huamin;Kwak, Kyung-sup
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.29 no.7A
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    • pp.781-785
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    • 2004
  • Mobile IP maintains Internet connectivity while Mobile Hosts moving from one Internet attachment point to another. However, Mobile If is not appropriate for seamless mobility. Some micromobility protocols were proposed to complement Mobile IP by offering fast and seamless handoff control in limited geographical areas. In this paper, a new scheme, based on path prediction and resource reservation, is proposed to reduce the handoff latency by trying to eliminate the link setup time for fast handoff in all-IP wireless networks. Analytical results show that the proposed scheme offers shorter handoff delay and can improve the handoff efficiency.

Improving Device-to-Device Connectivity with Responsive Web Technology

  • Park, Minsoo
    • International Journal of Internet, Broadcasting and Communication
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    • v.14 no.1
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    • pp.25-30
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    • 2022
  • Since Tim Berners-Lee introduced the idea of the web to the world in the late 1980s, the way information is produced, accessed and used has been constantly changing. This was once again an era of upheaval after Apple's Steve Jobs introduced the smartphone to the world in the mid-2000s. Before the advent of smart devices, web browsing was mainly done using desktops. After the advent of this device, the era of solving almost all human needs with a small PC in the palm of your hand has arrived. The necessity of seamless connectivity between devices, which are constantly emerging and evolving, asks our attention more than ever. In this study, we will discuss a case of design and development of a national open access website, which is optimized for dynamic online user behaviors with diverse devices. Our goal is to provide one true web for people to use in their environment. Device makers need to provide products identical to the desktop environment as much as possible. Service providers should also provide services optimized for each device in hyper-connected environments. Providing a web, optimized for user's online context, will eventually result in a sustainable user experience.