SDN BASED MOBILITY MANAGEMENT FOR QOS MULTICASTING

김현숙 건국대학교 대학원 2017 국내박사

Overall mobile data traffic is expected to grow to 30.6 exabytes per month by 2020. The rapid growth of mobile communications necessitates practical support for IP mobility. IP multicast is a bandwidth-conserving technology that can be one of the solutions for the explosive growth of mobile communication data. Even though the requirement on mobile multicast is increasing, but most of the mobility protocols are designed separately from the multicast protocols. There are many issues for providing seamless multicast service in mobile networks because of the nature of the mobile network. In traditional mobile networks, IP multicast is enabled by deploying the multicast functions to Mobil-ity Access Routers (MAR). Multicast Router does not always exist when the mobile node is moving. However, in new network approach, Software Defined Network (SDN) simplifies forwarding hardware controller by intelligent central-ized software. In SDN based Distributed Mobility Management (DMM), it redirects the flow from previous OpenFlow Switch (OFS) to current OFS when MN move cross the OFSs. It diminishes the overhead in some degree, but still, multicast signaling process remains after the handover is completed. In this dissertation, a centralized group management scheme is proposed to perform the group join process while handover is taking place. The author moves all multicast mobility management functions to SDN controller to mini-mize the effect on multicast flows during handover. The intuition behind this proposal is simple, move all the multicast functions to the SDN controller and handle the multicast flows with mobility considered. With proposed scheme, multicast anchor and unnecessary traffic redirection can be removed with the help of global view of network topology in the SDN controller. Because the handover is time sensitive, the author implements proposed the idea as a mod-ule of SDN controller - OpenDaylight. Several experiments are performed in SDN testbed with proposed multicast mobility management application. The comparison with PMIP based DMM and SDN based DMM architecture are performed. On average, the result has proved that checking the multicast group member in advance is slightly better than tunneling and redirecting the flow af-ter the handover is completed. It can reduce process time of group join after handover and multicast flows are available to be forwarded in a distributed manner without any centralized multicast anchor. In this dissertation also propose a building multicast routing tree by KMB [24] algorithm with QoS considered finding best routing path for a source to destination in limited network condition. The proposed mechanism takes two QoS factors (bandwidth and delay) into account to make the routing decision. Also, propose solutions for many joins and leave the process in the multicast tree. When constructing Steiner Tree, the author uses Floyd’s Algorithm to com-pute the all shortest path information for later use. Through simulation using GroupFlow, the average time of initializing step and its multicast tree path length. The computing time is much longer, but total path length is shorter in Steiner Tree and vice versa. In a time-consuming aspect can take great benefit. In the case of QoS Aware, because of the application QoS requirement check-ing process, it takes a long time than others. Steiner tree will be recomputed when there is a path can not satisfy the application QoS requirement. In this case, is taking longer time than just reconstructing Steiner tree. Even though our mechanism takes a long time to check the QoS satisfaction, but still it takes a shorter time than reconstructing Steiner Tree every time. 기존 멀티캐스트 프로토콜은 이동 단말의 이동성을 지원하는 이동성 프로토콜과 분리되어 설계되었다. 현재 모바일 네트워크에서는 멀티 캐스트 기능을 Mobility Access Routers (MAR)에 배포하여 IP 멀티캐스트를 사용하게 된다. 또한 MAR에서 이동단말의 그룹 가입 및 탈퇴를 위한 신호처리도 담당해야 한다. 즉 이동단말이 이동할 때 멀티캐스트 트래픽은 멀티캐스트 앵커로부터 현재 MAR로 터널링기법을 통해서 전달 된다. 이러한 방식으로 멀티캐스트를 제공할 경우, 진행중인 멀티캐스트 트래픽에 서비스중단 또는 터널링 오버헤드 등 결과를 초래한다. 따라서 본 논문에서는 멀티캐스트를 위한 SDN 기반 이동성 관리 기법을 설계하고 제안하였다. 멀티캐스트 그룹 가입과정을 핸드 오버 중에 시작할 수 있기 때문에 이동 중인 단말이 사용하는 멀티캐스트 서비스에 미치는 영향을 최소화할 수 있다. 또한 멀티캐스트 애플리케이션의 QoS 요구사항을 반영하여 멀티캐스트 트리 구성 알고리즘을 제안하였다. 이동성을 고려하여, 단말이 이동 후 OVS가 그룹멤버일 경우, 멀티캐스트를 그냥 받으면 되지만, 아닌 경우 제일 가까운 멀티캐스트 멤버 OVS를 찾아 연결 시켜준다. 또한 본 논문에서는 모바일 노드의 이동성을 고려한 멀티캐스트를 위한 SDN 기반 QoS 라우팅 메커니즘을 설계하고 제안하였다. 우선, 멀티캐스트 소스와 멀티캐스트 클라이언트가 결정되면, 이들과 연결된 첫 번째 OFS 들을 Steiner 포인트로 지정한 다음, KMB 알고리즘을 이용하여 Steiner 트리를 구성한다. 또한 이동성 네트워크의 특성상, 빈번한 이동단말의 이동으로 인해 멀티캐스트 그룹 가입탈퇴도 자주 일어난다. 매번 이동할 때 마다 이에 따른 새로운 링크가 형성되고 불필요한 링크는 멀티캐스트 트리에서 삭제된다. 변경된 멀티캐스트 트리가 더 이상 멀티캐스트 서비스가 품질을 보장할 수 없을 경우, 트리를 재구성한다. 핸드오버과정은 시간에 민감한 점을 고려하여, 이동성관리 애플리케이션을 SDN 컨트롤러 내부에 애플리케이션으로 구현함으로 이동감지 및 경로설정에 걸리는 시간을 최소화하였다. 또한 GroupFlow를 이용하여 KMB 알고리즘을 이용하여 Steiner 트리 구성 알고리즘을 구현하여 실험을 진행하다. 그 결과, QoS 보장과 최적화된 멀티캐스트 트리 구성을 위하여 시간은 좀 더 많이 걸린 것으로 나타났으나, 매번 QoS 보장을 위하여 트리 재구성하는 경우보다는 시간적으로 좋은 효율을 보였다. 마지막으로, OpenDaylight 컨트롤러를 중심으로 Open vSwitch를 사용하여 SDN 기반의 테스트 베드를 구성하고 다양한 시나리오로 실험을 진행하였다. 실험 결과에 따르면 제안 된 솔루션의 타당성을 충분히 입증 할 수 있었으며, PMIP 기반 DMM 및 SDN 기반 DMM 핸드오버 과정이 끝난 후 첫 번째 멀티캐스트 패킷을 받을 때까지 걸리는 시간을 비교했다. 제안한 메커니즘이 보다 나은 성능을 보였다.

Mobility Support for 5G Networks and Beyond: New Challenges and Novel Solutions

Li, Qianru ProQuest Dissertations & Theses University of Cali 2022 해외박사(DDOD)

Cellular networks are the only large-scale system that supports mobility. It has successfully provided anytime and anywhere connectivity by deploying dense cell towers and switching the serving cell when the client leaves its coverage. To meet stringent network service requirements, 5G/4G has been actively enhancing network capabilities (e.g., mmWave bands, carrier aggregation, multi-carrier access). Mobility support also plays a critical role in achieving high reliability and throughput. They are desired not only in low mobility but also in extreme mobility; extreme mobility has become more common given high-speed rails and mmWave cells with a small coverage. However, the current practice fails to address the challenges. The culprit is that legacy design is confined to connectivity and can hardly match upgraded network capability and demand. This dissertation showcases reliability and throughput issues in extreme and low mobility. For reliability, failures increase vastly in extreme mobility. Multi-mobile-carrier access (e.g., Google Fi) incurs oscillation among carriers akin to BGP loops. Furthermore, mobility support largely misses cells with high throughput despite the excellent potential of carrier aggregation and rich radio resources. Throughput loss is more considerable with mmWave cells due to less decision-making time. This dissertation proposes revolutionary solutions regarding the limitation of legacy mobility support design:1. We enhance network reliability. We devise REM, the first movement-based mobility management, to combat dramatic wireless dynamics and mitigate failures in extreme mobility. In addition, we eliminate inter-carrier switching loops by resolving conflicts in multiple parties' policies.2. Our design boosts throughput via better utilization of increased radio resources and advanced technologies. We devise CA++ to fulfill CA potentials over a broad frequency spectrum, including mmWave cells. It reforms the conventional cell-by-cell selection into the parallel design, which relaxes the dilemma of making a rapid or good selection. We design RPerf, a ready-to-launch algorithm to enable throughput-aware cell selection with reconfiguration.

Mobility개념의 변화를 통한 현대 도시공간의 재해석 및 적용 가능성에 관한 연구

심경아 인하대학교 일반대학원 2007 국내석사

It is not exaggerated to say that the sense of place in contemporary cities is determined by the fluidity of infrastructure, by which architecture can be always altered in its location and character within the cities. Accordingly, the act of designing in today's architecture and urbanism requires everlasting process that is not predicating any articulated results, while at the same time it pays great attention to space potential implied by both the everyday-ness and non-place-ness of contemporary urbanism; that is manipulated by infrastructure indeterminacy. It is, in other words, necessary for designers to reinterpret and potentialize any supplementary components into spatial meaning and reconsider the role and the significance of architectural design through an exploration of today's fluid context. This study intends to investigate new concept of mobility arisen in the realm of fluid urban condition, to examine ways how such mobility can be reflected on today's urban design, and to explore new design strategy to apply these new ideas to the 21st century's urban architecture. The main argument is focused on the change of meaning in mobility and its applicability in urban design process. In the argument, the concept of mobility in space is, in particular, viewed as the subject of movement, while investigated in the difference between exiting studies and the new discourse of mobility introduced in the First Rotterdam International Architectural Biennale in 2003, to examine the process of change in its meaning. Then, the possibility and significance of space without the sense of place in the contemporary city will be examined on the basis of a new concept of mobility that is expanding from the notion of architectural space to that of urban space. And later, the study will be verified by the exploration of the exhibition hall and displaying methods used in the Rotterdam Biennale to measure the architectural applicability of the new concept of mobility. 현대 건축과 도시는 장소와 흐름이 생성되고 만나는 인프라 스트럭쳐의 유동적인 상황으로 인식된다. 즉, 디자인 행위가 최종 순간까지도 예측 불가능한 끊임없는 과정(process)의 조건에 놓여 있다는 것이다. 그러므로 인프라스트럭쳐 적 도시조건을 감안한다면 현대도시의 일상적이며 비장소적(non-place) 조건이 제시하는 공간적 잠재성을 주시해야 한다. 즉, 부가적인 요소들에 대한 새로운 해석을 통해 공간적 가능성과 의미를 도출하도록 해야 하는 것이다. 그리고 이러한 유동적 컨텍스트에 대한 탐구를 통해 건축 디자인의 새로운 역할과 의의에 대해 질문을 던져 보아야 할 것이다. 따라서 이 연구는 이러한 유동적인 도시 상황으로부터 도출되는 새로운 운동성(mobility)개념에 대해 고찰하고, 이러한 운동성이 어떻게 도시에 반영될 수 있는가를 살펴 본 후, 21세기 도시 건축에서 반영될 수 있는 새로운 공간적 가능성과 디자인 전략에 대해 진단해보는데 그 목적이 있다. 이 연구는 운동성(mobility)의 의미변화와 이에 대한 도시적 적용의 문제를 다루고자 한다. 특히 공간의 운동성 개념을 운동의 주체라는 측면에서 조명하고, 기존의 연구에서 정의하고 있는 모빌리티에 대한 내용과 작금에 대두되는 모빌리티의 정체를 제 1회 로테르담 국제건축 비엔날레 2003에서 제기되었던 담론을 중심으로 고찰한 후, 이들의 내용을 비교하여 개념적 변화의 과정을 살펴보고자 한다. 다음으로 공간에서 도시적 개념으로 확대되는 모빌리티의 새로운 개념을 바탕으로 현대도시의 장소성 없는 공간과 가능성, 그리고 의미를 밝혀볼 것이다. 그리고 연구의 검증을 위해 건축과 문화적 사례들과 비엔날레가 열린 로테르담과 전시장소, 전시 기획 방법을 차용하여 이러한 개념의 건축적 적용가능성을 타진하고자 한다.

Walking and Rolling: Evaluating Technology to Support Multimodal Mobility for Individuals with Disabilities

Zaino, Nicole L University of Washington ProQuest Dissertations & 2023 해외박사(DDOD)

Mobility is considered a human right and enables freedom. Self-initiated mobility is imperative for development of physical, cognitive, visual, and sensory abilities, and independence. Engineers design technology to support humans' many modes of mobility; whether that be walking, biking, crawling, or rolling (e.g., propelling a manual wheelchair, car, or powered wheelchair). For people with disabilities, technology that supports mobility includes surgical interventions, therapies, and mobility aids which facilitate independence and participation. This dissertation investigates the impact of a multitude of strategies designed to support mobility for individuals with disabilities. One large population within the disability community are individuals with cerebral palsy (CP). CP is the result of a brain injury at or near the time of birth and impacts mobility. Due to the unique nature of brain injuries, individuals with CP have heterogeneous disabilities that limit mobility and function. Elevated energy consumption during walking is a leading complaint of children and adults with CP that impacts endurance and community involvement. The causal mechanisms underlying elevated energy consumption for individuals with CP is unknown. One proposed cause of elevated energy consumption is muscle spasticity: velocity dependent resistance to stretch. We found that while a surgical intervention -- selective dorsal rhizotomy (SDR) -- did reduce spasticity, it did not reduce energy consumption during walking. These results not only demonstrates that spasticity is not a cause of elevated energy in CP, but also have large clinical implications as elevated energy consumption is commonly used as a selection criterion for SDR and "more efficient" walking and greater endurance are advertised as benefits of SDR. Despite advances in technology and design of many mainstream mobility devices (e.g., cars or bikes) over the past century, devices designed for individuals with disabilities have not seen this same level of innovation. This is due to a dearth of research in the field of mobility aid design. For example, despite ankle foot orthoses (AFOs) being the most ubiquitous mobility aid for individuals with CP, the basic design has not significantly changed and there are still many opportunities for improvement to support mobility. Using focus groups with individuals with CP and their caregivers who had experience with AFOs, we investigated the lived experiences of AFO provision, use, and impact. We found that AFOs can benefit mobility and independence. However, many challenges still exist that hinder AFO provision, including the confusing and lengthy provision process, the need for more education and information during provision, and AFO discomfort. "Early" or on-time mobility aid provision for infants and toddlers with disabilities is quite variable and there is no consensus of what is best with two different camps: (1) wait and see and (2) support mobility with technology as soon as possible. For young children with CP, orthoses and walking aids are the two most common types of devices they receive first. Yet, we do not know when or how most children first get these devices or the developmental impacts for this specific age group. We used surveys and interviews with caregivers and clinicians about the provision process of first mobility aids for young children with CP. We found that there are specific challenges for the provision and use of first mobility aids including, 1) requiring an agreement among clinicians on the provision timing, 2) which devices to use first, and 3) providing more enriched education and training for families.One under-explored but promising mode of first mobility for toddlers is powered mobility. Experiencing different postures is important for development in early years. Additionally, it has been proposed that using powered mobility in a standing posture can allow the child to have dual progression in mobility and body structure goals. However, the impacts of posture while engaging with and learning how to use powered mobility is unknown. Through an experimental study, we investigated how children with disabilities under the age of three engage with and learn to explore with powered mobility over four play visits in both seated and standing postures. We found that toddlers with a variety of disabilities or mobility delays were able to engage with the joystick and explore their environment in both postures. Each posture (seated and standing) had its own positive and negative impacts on joystick control, distance traveled, bodyweight support, and muscle activity. Specifically, in the standing posture participants had more joystick activations, traveled a shorter distance, loaded a similar amount of weight through their legs, and had greater muscle activity especially when driving (vs. stationary play). Our findings can motivate future investigations and device design to optimize posture and access to device control. Additionally, our results can guide how to best implement on-time powered mobility in clinical care, even as an intervention in a therapy setting.The work in this dissertation contributes to the fields of mechanical engineering and rehabilitation engineering through a comprehensive investigation of different technologies that individuals use to support and enhance their mobility. I employ methods from engineering, biomechanics, rehabilitation science, and disability studies fields to holistically answer these questions to better understand and support mobility for individuals with disabilities. This work will enable improved mobility aid design, provision, and use for individuals with disabilities.

Mobility modeling and mangement for next generation wireless networks

최우진 New Jersey Institute of Technology 2003 해외박사

Mobility modeling and management jin wireless networks are the set of tasks performed in order to model motion patterns, predict trafectories, get information on mobiles' whereabouts and to make use of this information in handoff, routing, location management, resource allocation and other functions. In the literature, the speed of mobile is often and misleadingly referred to as the level of mobility, such as "high" or "low" mobility. This dissertation presents an information theoretic approach to mobility modeling and management, in wihich mobility is considered as a measure of uncertainty in mobile's trajectory, that is, the mobilitly is low if the trajectory of a mobile is highly predictble even if the mobile is moving with high speed. On the other hand, the mobility is high if the trajectory of the mobile is highly erratic. Based jon this mobility modeling concept, we classify mobiles into predictable and non-predictable mobility calsses and optimize network operations for each mobility class. The dynamic mobility classification technique is applied to various mobility related issues of the next generation wireless networks such as location management, location-based services, and energy efficient routing in multihop cellular networks.

Distributed Mobility Management with the Identifier-Locator Separation for Support of IP Mobility : 인터넷 이동성 지원을 위한 Identifier/Locator 분리 기반 분산형 이동성 관리 기법

김지인 경북대학교 대학원 2016 국내박사

With the recent growth in smartphone services, the ‘mobile’ environment has become a key factor to consider in the design of the future Internet. However, today’s mobility management (MM) architectures such as Mobile IP and Proxy Mobile IP feature integration of data and control planes as well as centralized mobility control. This is because data packets are delivered via a central mobility agent such as Home Agent and Local Mobility Anchor, tight integration of the data and control planes can make a routing path non-optimal. Furthermore, the centralized mobility control mechanism tends to increase traffic overhead due to the processing of both data and control packets at a central agent. To address these problems, in this thesis, it is presented a new distributed mobility management scheme for the IP mobility, named ID/LOC separation mobility management scheme. The ID/LOC separation mobility management scheme was mainly designed as follows: 1) separation of data and control planes for getting an optimal data path; 2) distributed identifier-locator mapping control for alleviating traffic overhead at a central agent. In this thesis, the ID/LOC separation mobility management scheme was implemented using OpenFlow and Click Modular Router over a Linux platform and then evaluated through a set of experiments and realistic scenarios for validation, it is operated two pilots over the testbed. For performance analysis, it is performed the experimentation and numerical analysis. The experimental results show that the proposed ID/LOC separation mobility management scheme can not only provide the mobility management efficiently, but also support the backward compatibility for the current IPv6 applications and an Internet Protocol network. From the numerical analysis, it is also seen that the ID/LOC separation mobility management scheme performs better than existing identifier-locator separation schemes, such as Proxy Mobile IPv6 (PMIP), Host Identity Protocol (HIP) and Locator/ID Separation Protocol (LISP), in terms of control and data delivery signalling. 오늘날 Mobile IP와 Proxy Mobile IP와 같은 이동성 관리 구조는 중앙 집중형 이동성 제어뿐만 아니라 데이터와 제어 계층이 통합되어 있다. 그러나 데이터 패킷이 홈 에이전트 혹은 로컬 모빌리티 앵커와 같은 중앙 집중화 된 이동성 제어 에이전트를 통해서 전달되고, 데이터와 제어 계층의 긴밀한 통합으로 인해 라우팅 경로가 비 효율적이다. 게다가, 중앙 집중형 이동성 제어 기법은 데이터와 제어 패킷이 모두 중앙 에이전트에서 처리되기 때문에 트래픽 부하를 증가시키는 경향이 있다. 이러한 문제를 해결하기 위해 본 학위 논문에서는 인터넷 이동성 지원을 위한 Identifier/Locator 분리 기반 분산형 이동성 관리 기법을 제시한다. 본 학위 논문에서 제안하는 기법은 다음 규칙에 따라 고안 되었다. 1) 최적화된 데이터 경로를 얻기 위한 데이터와 제어 계층의 분리; 2) 중앙 집중형 에이전트에서 트래픽 오버헤드를 줄이기 위해 식별자와 위치자 매핑 제어를 분산하였다. 본 학위 논문에서 제안하고 있는 인터넷 이동성 지원을 위한 Identifier/Locator 분리 기반 분산형 이동성 관리 기법은 리눅스 플랫폼 상에서 OpenFlow와 Click Modular Router를 사용하여 구현되었다. 그리고 두 개의 세트를 마련하여 실제 시나리오에 따른 실험을 수행하였다. 실험 결과 MOFI 구조는 효율적인 이동성 관리를 제공할 뿐만 아니라, 기존의 인터넷 프로토콜 네트워크와 현재의 IPv6 어플리케이션과의 호환성을 제공한다.

Global Mobility and Security Enhancing Scheme for Heterogeneous Mobile Networks Based on Proxy-MIPv6

이승현 성균관대학교 일반대학원 2014 국내박사

기존에 개발된 호스트 기반의 네트워크 이동성 관리 프로토콜은 모바일 노드에 의해 생성하는 시그널에 의존하였기 때문에 실제 무선 네트워크 환경에서는 널리 사용되지 못한다는 단점을 가진다. 이러한 문제점을 해결하기 위해 IETF 에서는 네트워크 기반의 이동성 관리 프로토콜인 Proxy Mobile IPv6 (P-MIPv6)를 표준화를 진행하였다. 그러나 네트워크 기반의 관리 프로토콜인 P-MIPv6의 경우에도 로컬 이동성만을 위해 설계되었기 때문에 글로벌 이동성의 지원이 취약하다는 단점을 가진다. 따라서 본 학위 논문에서는 네트워크 기반의 이동성 관리 프로토콜을 확장하여 글로벌 이동성에 대한 연구를 진행하였다. 본 학위 논문의 최종 목표는 P-MIPv6의 단점인 로컬 이동성에 대해 이기종 무선 네트워크 환경에서 P-MIPv6 기반의 글로벌 이동성 향상 연구와 글로벌 이동성에서의 효율적인 인증과정이 수행되도록 제시한다. 이를 위해 제안된 Proxy-LMA 기법은 시그널링 메시지에 대한 메시지 변환을 보장하고 프로토콜 전환이 용이하도록 셀 사이에서 메시지 변환 게이트웨이 역할을 담당한다. Proxy-LMA 게이트웨이 기법은 다른 도메인 간의 이동 시 등록을 요청하는 MN의 ID 정보와 이동하는 예상 경로를 파악한다. 이동하는 예상 경로는 상호 인접하는 네트워크의 구성에 따라 다를 수 있다. 핸드오버에 대한 신호 요청 메시지(Handover Request Message)와 등록과 이동 간의 시그너링에 따른 데이터를 저장하는 등의 처리 과정을 수행한다. 성능평가 결과, 본 논문에서 제시한 Proxy-LMA 게이트웨이 방안은 Single Registration (SR)/Multiple Registration (MR) 등과 비교하여 네트워크 트래픽 감소, 빠른 응답 시간, 사용자의 위치 파악, 빠른 쿼리 수행 및 위치 정보 업데이트 등의 정보 수집 절차에서 우수함을 보여준다. 또한 본 학위 논문에서는 이기종 간의 인증 절차 등을 고려하여 Proxy-AAA 기법을 제시하였다. 제안된 Proxy-AAA 기법은 확장된 AAA 기능을 이용하여 Proxy-LMA와의 결합을 통해 글로벌 이동성과 안전성을 높이기 위한 방법을 제안한다. 기존의 AAA의 방법과 비교하여 지연시간과 추가적인 오버헤드를 줄이는 방법으로 테스트를 진행하였다. 실험의 결과로서 Proxy-AAA 기법의 전체 오버헤드는 기존 AAA기법 보다 작은 수치적 결과를 확인할 수 있다. 이는 로컬 이동성을 지원하는 P-MIPv6의 구조에서 AAA 기능을 확장한 Proxy-AAA 인증 기법이 보다 효율적으로 도메인 내부와 도메인 간의 이동성 지원과 관련하여 적용 가능함을 보여준다. Proxy-LMA 기법과 Proxy-AAA 기법은 향후 이동성 프로토콜의 응용 서비스에서 사용자가 요구하는 보안성의 신뢰성 및 QoS(Quality of Service)를 만족시킬 수 있을 것으로 예상한다. In NGWN (Next Generation Wireless Network) environment, network convergence are gaining popularity through the advance of communication technology by the internetworking of access networks. Network convergence is aimed to implementation of next generation integrated network which is provided high-quality multimedia service to anywhere, anytime about the access networks of telecommunications, broadcasting, and internet, etc. This dissertation is proposed the Proxy-LMA (Global Mobile IP-based Internetworking System, GMI2S) gateway scheme to support the global mobility and interoperability. Proxy-LMA gateway guarantees message transit about signaling message and takes a role for the gateway of message transmission to switch the protocol easily. P-MIPv6 provides an effective costs than MIPv6. P-MIPv6 has the limitation as mobility management to the other domains. In the other words, P-MIPv6 is designed only the local mobility scopes that is excludes the global mobility. Also, Proxy-LMA can be support the global mobility and interoperability to overcome the disadvantages of local mobility. This dissertation shows the its results through the performance analysis and evaluation. In the other scheme, the proposed Proxy-AAA is designed from a hierarchical AAA, which is supported for fast authentication in the P-MIPv6. AAA server is placed on the LMA, reduces the cost of authentication in domain by the short and simple fast moving and hierarchical authentication. The proposed Proxy-AAA scheme improves the existing authentication scheme and methods of binding update and is applied to not only the domain but also between several domains. Proxy-AAA in the one domain reuses the LMA-based session key in the move and authentication of a hierarchical mobile IPv6. Proxy-AAA between domains reuses the AAA server-based session key and induce the direct transmission between LMAs. This Proxy-AAA scheme can be support the global mobility and interoperability to overcome the disadvantages of local mobility. This dissertation shows effective results than the existing AAA function through the performance analysis and evaluation. Finally, the performance evaluation shows the results that is effective results than the traditional AAA scheme.

Social Mobility over the Life Course of Migration: Transition, Pattern, and Self-Selection

Chen, Zhenxiang ProQuest Dissertations & Theses University of Cali 2021 해외박사(DDOD)

Studies on migrant mobility over the life course have not considered migration stages over lifetime migration. In this dissertation, I examine migrant social mobility over the life course of migration, situating mobility within frameworks of life-course transitions, patterns, and self-selection. By applying this theoretical framework, I identify meaningful migration stages by the dimension of interest. These migration stages form migration transitions and patterns that largely shape migrant social mobility. Additionally, I explore and consider migrant self-selection from a life-course angle. Building on this framework, I theorize and test two pathways to explain migrant social mobility over lifetime migration: (i) self-selecting into migration transitions and patterns; and (ii) realizing different social mobility outcomes within each transition or pattern. By doing so, I decompose social mobility over lifetime migration into differences between migration transitions or patterns and differences within each migration transition or pattern. I apply various selection models to explore transition- and pattern-specific pathways while accounting for potential selection bias. I apply this framework to three dimensions – the temporal dimension, documentation status dimension, and migration status dimension – and rely on Mexico-US international migration and China rural-to-urban migration. The overall results show that migrant social mobility over lifetime migration is explained by the self-selection process into migration transitions and patterns and social mobility process within each transition or pattern. These two processes are identified for all three dimensions of migration and for both Mexico-US international migration and China rural-to-urban migration. I first find that different migration transitions and patterns are associated with different social mobility outcomes, measured by occupational attainment, wages, and economic integration. Then I verify that migrants self-select into these migration transitions and patterns. Individual characteristics and external factors drive this process. Furthermore, migrants within each transition or pattern still realize divergent social mobility outcomes given their individual characteristics and external factors to which they are exposed. The factors that explain social mobility outcomes within each transition or pattern often have a strong effect. Moreover, their effects are transition- and pattern-specific, suggesting that migration transitions and patterns shape social mobility pathways.

Communication-Aware Mobility Control in Wireless Mobile Networks

노희태 연세대학교 대학원 2012 국내박사

As the communication technologies are enhanced, various applications are emerging in wireless networks. Among them, recently, there are much attention on the networked mobile nodes, e.g., a team of mobile robots, unmanned vehicles or scouts, and etc., in wireless mobile networks. According to whether the mobility of nodes can be controlled to improve the communication quality by the network operator or itself, in this thesis, we classify nodes in wireless networks into two classes: nodes with controllable mobility and nodes with uncontrollable mobility. For example, in WLANs, we can decide the position of the access point to improve the qualities of communications between it and users, while we cannot control the positions of users, which want to communicate with the access point. Then, we can call the access point a node with controllable mobility and a user a node with uncontrollable mobility. For another example, in the battlefield scenario, some nodes, which are freely moving in a certain area, may be dedicated to concentrate on only accomplishment of their mission, while the others may be dedicated to assist the communications between nodes so that they can change their positions by adapting to the positions of other nodes to improve the qualities of communications between nodes. Then, we can call the former nodes with uncontrollable mobility and the latter nodes with controllable mobility. In this thesis, we study the problem for mobility control of nodes with controllable mobility with adapting to the positions of nodes with uncontrollable mobility to improve the network performance in wireless mobile networks. In this thesis, we consider three scenarios in wireless mobile networks. In the first scenario, we consider a network that consists of a single relay node with controllable mobility and multiple nodes with uncontrollable mobility. A node with uncontrollable mobility can directly communicate only with the relay node, while communicating with another node with uncontrollable mobility via the relay node. This system model corresponds to the star topology network such as WPANs and WLANs, which consist of a single access point and multiple clients, and the subnetwork in wireless mesh networks that consists of one mesh router and multiple mesh clients that are connected to the mesh router. In this scenario, we study the problem for the optimal placement of the relay node with adapting to the positions of all nodes with uncontrollable mobility. In addition, we find the optimal scheduling of all nodes with uncontrollable mobility to communicate with the relay node. Since we can consider the relay node as a centralized controller, which is in one-hop distance from other nodes, we develop a centralized algorithm for finding the optimal position of the relay node as well as optimal node scheduling by using the optimization theoretic approach. In the second scenario, we consider a network that consists of mobile nodes, which are aligned on a straight line. Some of nodes have controllable mobility, while the others have uncontrollable mobility. This system model corresponds to the linear vehicular networks. In this scenario, we study the problem for the mobility control of nodes with controllable mobility with adapting to the positions of their neighbor nodes. We first solve the problem by using the optimization theoretic approach and develop a centralized algorithm for mobility control. However, since it is hard to implement a centralized algorithm in this system model, we also develop a distributed algorithm by using the game theoretic approach. In the last scenario, we consider a network that consists of mobile nodes in a two-dimensional area, which are performing their mission while communicating with their neighbor nodes. In this scenario, we study the problem for the mobility control of all nodes with considering their satisfaction on both the accomplishment of their mission and the qualities of communications with their neighbor nodes. Similar to the second scenario, since it is hard to implement a centralized algorithm in this system model, we develop a distributed algorithm by using the game theoretic approach. In all the above scenarios, we formulate the optimization problem for mobility control in the network utility maximization (NUM) framework. Then, we solve the problem by using the optimization theoretic approach and/or the game theoretic approach to develop the algorithms for mobility control, which are suitable to be implemented in each scenario. The numerical results show that we can significantly improve the network performance by appropriately utilizing the controllable mobility of nodes in wireless mobile networks.

Combinatorial mobile IP : a study on efficient mobility management using minimized paging and local registration in mobile IP environments

최태환 Graduate School, Yonsei University 2002 국내석사

최근 인터넷에서 이동성을 관리하는 기법으로 Mobile IP가 각광을 받고 있다. Mobile IP는 인터넷에서 무선 데이터 통신의 기반 기술로 자리를 잡았음에 확실하게 보인다. 셀률라 망과는 다르게 인터넷은 분산 시스템이다. Mobile IP는 매크로 이동성 측면에서는 적합하나 마이크로 이동성 측면에서는 적합하지 못하다는 점이 있다. 인터넷에서 이동성 관리는 인터넷이 내재적으로 분산 시스템이며 위치 정보가 인터넷 상에 분산되어 있다는 점 때문에 어려운 점이 있다. 반면에 셀률라 망에서 이동성 관리는 셀률라 망이 중앙 집중 시스템이므로 더 자연스럽다는 점이 있다. 셀률라 망에서 이동성 관리는 위치 갱신과 페이징 기법을 사용하고 있다. 반면에 Mobile IP는 단지 등록 방식만을 사용하고 잇다. 현재 많은 연구가 Mobile IP의 이동성 관리를 향상시키기 위해 만들어 졌다. 페이징과 계층적인 구조가 Mobile IP 환경에서 이동성 관리를 위해 제안되어 지고 있다. 페이징과 계층적 구조는 Mobile IP를 위해 새롭게 태어난 기술이 아니라 실제로 전화망에서 많이 이용되는 방식이다. 이러한 점은 Mobile IP에서의 이동성 관리가 셀률라 망에서의 이동성 관리를 많이 채용하면서 발전되오고 있다는 사실을 말해 주는 것이다. 셀률라 망은 상업적으로 구현되어 있고 신뢰성 있고 견고하고 자연스러운 연결로 가입자들에게 서비스를 제공해 주고 있다. 셀률라 망에 비해서 Mobile IP는 늦게 출발하였지만 인터넷은 계속적으로 증가하는 추세이고 결국에는 Mobile IP가 차세대 통신에서 이동 네트워킹을 위한 셀률라 망을 대체하게 될 것이다. 본 논문에서는 어떻게 셀률라 망의 이동성 관리 기법을 받아 들여서 인터넷의 특성을 이용하여 적용하는지를 보일 것이다. 셀률라 망에서 많이 사용되는 계층적 구조와 페이징을 사용하지만 Mobile IP에 다르게 적용시킬 것이다. 이런 방식으로 전체 시그날 비용은 Mobile IP Regional Registration과 P-MIP와 같은 다른 마이크로 이동성 프로토콜에 비하여 줄어들었다는 것을 보일 것이다. Recent research on implementing mobility on the Internet is focused on using Mobile IP. Clearly, Mobile IP is the framework of wireless data networking on the Internet. Unlike a cellular network, the Internet is a distributed system. Mobile IP is well suited for macro-mobility but not for micro-mobility. Intrinsically, mobility management is hard to come by on the Internet since the Internet depends on the distributed nature of networks and location information is distributed around the Internet. On the contrary, the mobility management of cellular networks is more natural than that of the Internet since the cellular network is a centralized system. In the cellular network, mobility management uses two schemes such as location updates and paging. On the other hand, Mobile IP uses only registration. Currently, a lot of research efforts are being created to improve Mobile IP mobility management. Paging and hierarchical architecture are used for most proposed mobility management schemes in Mobile IP environments. Paging and hierarchical architecture are not newly developed techniques for Mobile IP. They are widely used techniques for telephone networks. This shows that mobility management in Mobile IP is progressing toward simulating mobility management on cellular networks. Cellular networks are commercially implemented and serving users with reliable, robust and seamless mobility. Compared to cellular networks, Mobile IP is the late comer. However, the Internet is ever-growing and Mobile IP will be the substitute of cellular networks for mobile networking in the next generation network. In this paper, we present how to adopt mobility management schemes on cellular networks and adapt them in Mobile IP without disrupting the nature of the Internet. We adopt widely used mobility management schemes such as hierarchical architecture and paging in cellular networks but adapt them to Mobile IP differently. We restricts paging to the area that has to be paged by using local registrations. In this way, we show that the total signaling costs are reduced compared to other micro-mobility protocols such as Mobile IP Regional Registration and P-MIP.