고영배 Lim, Keun Woo 2014-02 16254 https://aurora.ajou.ac.kr/handle/2018.oak/11083 학위논문(박사)--아주대학교 일반대학원 :컴퓨터공학과,2014. 2 본 논문에서는 WLAN 기반 멀티 홉 네트워크에서 데이터를 보급할 때 서비스 품질 (QoS) 을 향상시키기 위한 효율적인 기술에 대해 연구한다. 스마트폰 및 이동 네트워킹 기술이 큰 발전을 이룸에 따라, 새로운 무선 네트워킹 서비스 및 어플리케이션이 대두될 것으로 기대되고 있다. 이 트랜드를 따라 WLAN 기반의 네트워킹 제품 및 디바이스가 미래 서비스를 지원하기 위한 가장 핵심 기술로 떠오르고 있다. 하지만, 기존 WLAN 환경에서의 QoS 를 지원하기 위한 연구는 미래의 다양한 서비스 및 어플리케이션이 요구하는 요구사항을 만족할 수 없다. 그렇기 때문에, WLAN 기반의 통신 기술은 미래의 다양한 서비스 지원을 위해 이러한 요구사항을 충족하고 효율적인 QoS 를 지원할 수 있는 방법을 제시하여야 한다. 본 논문에서는 WLAN 기반 멀티 홉 네트워킹 환경의 다양한 미래 시나리오 및 사용 예시를 분석하고 이러한 환경에서 발생할 수 있는 문제점을 분석한다. 또한, 이러한 문제점을 해결하기 위하여 새로운 기술을 제시하고, 성능 분석을 통해 해당 기술들이 미래 다양한 WLAN 기반 서비스의 효율성을 높일 수 있다는 것을 증명한다. 특히 QoS 향상을 위한 다음 3가지 기술에 초점을 맞춘다: 1) 차량 통신 시스템에서의 QoS 향상 기술, 2) 실시간 멀티미디어 감시 시스템 기술, 3) 에너지 효율적인 QoS 향상 기술. 각각의 QoS 향상 기술은 WLAN 기반 멀티 홉 네트워킹 환경에서 요구하는 다양한 요구 사항에 맞춰 서비스 품질을 향상시킬 수 있을 것이라 기대된다. CHAPTER I INTRODUCTION I.A Contributions of this Thesis I.B Overview of the Thesis CHAPTER II BACKGROUND AND RELATED WORK II.A IEEE 802.11 WLAN standard III.A.1 Service Differentiation III.A.2 Multi-hop routing III.A.3 Mobility Management III.A.4 Wi-Fi Direct for mobile D2D communication II.B Taxonomy of QoS in WLAN based networks II.C Work on Ensuring Mobile Reliability II.C.1 Related Work on Fast Handover II.C.2 Related Work on Mobile Data Provisioning II.D Work on WLAN Access Control II.D.1 Related Work on Rate Control II.D.2 Related Work on Multi-hop Flow Control II.D.3 Related Work on Admission Control II.E Work on Service Differentiation II.E.1 Related Work on Queue-based Service Differentiation II.E.2 Related Work on Station-based Service Differentiation II.F Design Considerations for enhancing QoS in future services CHAPTER III QOS-ENHANCED DATA HARVESTING IN VEHICULAR NETWORKS III.A Background III.B Proposed Scheme III.B.1 Scheme 1: Multi-hop Data Harvesting with Replicas (MDH-R) III.B.2 Scheme 2: Multi-hop Data Harvesting with Replicas and Aggregation (MDH-RA) III.C Performance Evaluation III.C.1 Simulation Environments III.C.2 Simulation Results of MDH-R III.C.3 Simulation Results of MDH-RA III.D Chapter Summary CHAPTER IV REAL-TIME DATA DISSEMINATION IN WLAN MESH NETWORKS IV.A Background IV.B Proposed Scheme IV.B.1 Adaptive Mesh Network Architecture IV.B.2 Multi-Gateway Route Selection IV.B.3 Congestion Prediction IV.B.4 Congestion Avoidance IV.B.5 Routing Loop Prevention IV.B.6 Example of MGR-CA Operation IV.C Performance Evaluation IV.C.1 Testbed Implementation IV.C.2 Simulation Results IV.D Chapter Summary CHAPTER V POWER-EFFICIENT QOS IN WLAN BASED D2D ENVIRONMENTS V.A Background V.B Proposed Scheme V.B.1 Problem Statement V.B.2 Dynamically Synchronized Power Management V.B.3 Adaptive CTWindow Control (AC) V.B.4 Adaptive Temporary CTWindow Control (AT) V.C Performance Evaluation V.C.1 Formulation of Duty Cycle and End-to-End delay V.C.2 Performance Evaluation V.C.3 Formulation and Evaluation of AC and AT control V.D Chapter Summary CHAPTER VI CONCLUSION eng The Graduate School, Ajou University 아주대학교 논문은 저작권에 의해 보호받습니다. WLAN 기반 멀티 홉 네트워크에서 데이터 보급을 위한 QoS 향상 프로토콜 Lim Keun-Woo Thesis 아주대학교 일반대학원 Lim Keun-Woo 일반대학원 컴퓨터공학과 2014. 2 Doctoral http://dcoll.ajou.ac.kr:9080/dcollection/jsp/common/DcLoOrgPer.jsp?sItemId=000000016254 This thesis focuses on methods of enhancing Quality-of-Service (QoS) in WLAN based multi-hop networks for more efficient data dissemination. With great advancements in the technology of smartphones and mobile networking, the global society is beginning to embrace another boom of various wireless networking services and applications. Following this trend, WLAN based networking devices and products have become the most popular means of data communication for supporting these future services. However, contrary to existing QoS researches conducted in WLAN environments, these future applications have unique demands and requirements depending on the type of service they provide. Therefore, as being the primary means of communication in the present and future alike, WLAN based communication technology must account for these difference in services and provide efficient means of supporting QoS for them. This thesis views various scenarios and use cases of WLAN based multi-hop networking environments and analyzes the problems that current WLAN systems may pose. To account for these problems, novel solutions are proposed and analyzed to show that the contributions in this thesis can greatly improve the efficiency of future WLAN based services. Especially, three technologies of supporting QoS are discussed: 1) Enhancing QoS for data dissemination in vehicular speed communications systems, 2) Streaming multimedia surveillance systems, and 3) Power efficient QoS for battery-limited systems. It is expected that each technology can improve the performance of QoS in WLAN based multi-hop networking applications depending on the various requirements that they demand.