Proxy mobile IPv6 기반의 mobile CDN 구현 방안 연구 = A study on realization of mobile CDN based on proxy mobile IPv6

다국어 초록 (Multilingual Abstract)

Nowadays the mobile devices such as smartphones, tablet PCs, and laptops have been spread all over the world and the mobile services on such devices have become much more diversified and bandwidth-demanding. It currently leads to great R&D efforts towards better economics and efficiency in the related technologies such as mobility management and service content delivery beyond the traditional technologies in current use.
This dissertation describes a realization method of the mobile content delivery network (CDN) on IP networks based on the proxy mobile IPv6 (PMIPv6). CDN is composed of many distributed content servers in a network, which is designed to deliver multimedia services efficiently and economically to users. The content servers near users can quickly deliver contents upon their request, which can in turn reduce the traffic in the networks by shortening the delivery path from the servers and users.
CDN has been recently applied to mobile communication networks to realize the mobile CDN, which is generally implemented by overlaying the CDN service structure over the existing mobile communication networks. Therefore, the content management of CDN operates independently but coupled with the mobility handling signaling of the mobile communication network to serve the contents to moving users seamlessly. It can be figured out as a logical combination of two heterogeneous networks, causing great complexities and restrictions in the content distribution management, network scalability, flexibility in upgrading evolution etc.
On the other hand, the mobile Internet protocol (MIP) has been developed so that PMIPv6, a network-based mobility management protocol standard, is now employed into the advanced mobile networks in order to handle the ever-increasing Internet-based services efficiently. The core functional entities of PMIPv6 are the local mobility anchor (LMA) and the mobile access gateway (MAG). In PMIPv6, mobile nodes (MNs) do not participate in the mobile handover signaling procedures, which means that all the processing loads related to mobility management are taken care by the IP networks leaving MNs free from the processing loads related mobility management. It is noted that such the data-centric characteristics of PMIPv6 is to be in a quite good match with the requirements of the signaling mechanism of CDN.
This dissertation proposes the two key themes in realizing the mobile CDN on the IP networks: a mobile CDN architecture in the IP networks and a content handover scheme for realizing mobile content delivery based on PMIPv6.
In the first part, it was proposed a novel architecture for mobile CDN based on PMIPv6. The proposed architecture is composed of high level cache servers, low level cache servers, LMA, and MAG, combining the CDN network architecture and the PMIPv6-based IP network architecture. The proposed architecture forms a basis of constructing a mobile CDN on the IP network.
In the second part, a content handover scheme is proposed which is realized by combining the CDN content management scenario and the mobility management procedure of PMIPv6. The proposed handover scheme can be classified into two methods: A method of pre-downloading contents before handover and a method of selecting an optimal CDN-cache server when handover occurs. The proposed handover scheme can offer several benefits such as seamless handover and routing path optimization.
The proposed mobile CDN architecture and handover schemes are expected to be useful for seamlessly providing Internet multimedia contents in the mobile wireless communication environments.

목차 (Table of Contents)

• 1장 서론 1
• 2장 Mobile CDN의 구성기술 개요 7
• 2.1 Content Delivery Network 7
• 2.1.1 CDN의 기술 요소 10
• 2.1.2 Mobile CDN 15
• 2.2 Proxy Mobile IPv6 23
• 2.2.1 IP 이동성 지원 기법 25
• 3장 모바일 CDN을 위한 PMIPv6 기반의 CDN 구조 연구 28
• 3.1 제안된 PMIPv6 기반의 모바일 CDN의 구조 30
• 3.2 제안된 PMIPv6 기반의 모바일 CDN의 성능평가 32
• 3.2.1 Link stress 분석 35
• 3.2.2 Average hop count 분석 39
• 3.2.3 분석 결과 41
• 4장 모바일 CDN을 위한 PMIPv6 기반의 handover 기법 연구 48
• 4.1 PMIPv6가 채용된 CDN에서의 기존 handover 기법 55
• 4.2 PMIPv6가 채용된 CDN에서의 제안된 handover 기법 58
• 4.2.1 Handover 전에 일정량의 content를 미리 다운로드 받는 방법 59
• 4.2.2 최적의 CDN-cache 서버 선택 방법 61
• 4.3 PMIPv6가 채용된 CDN에서의 제안된 handover 시나리오 1
• (이동통신 네트워크 → 이동통신 네트워크로 handover) 62
• 4.3.1 CDN-cache 서버의 미변경 handover (시나리오 1) 63
• 4.3.2 CDN-cache 서버의 변경 handover (시나리오 1) 67
• 4.4 PMIPv6가 채용된 CDN에서의 제안된 handover 시나리오 2
• (이동통신 네트워크 → WLAN으로 handover) 70
• 4.4.1 CDN-cache 서버의 미변경 handover (시나리오 2) 72
• 4.4.2 CDN-cache 서버의 변경 handover (시나리오 2) 76
• 4.5 PMIPv6가 채용된 CDN에서의 제안된 handover 시나리오 3
• (WLAN → 이동통신 네트워크로 handover) 79
• 4.5.1 CDN-cache 서버의 미변경 handover (시나리오 3) 80
• 4.5.2 CDN-cache 서버의 변경 handover (시나리오 3) 83
• 4.6 제안된 handover 기법의 성능 평가 86
• 4.6.1 Handover latency 분석 87
• 4.6.2 Packet loss time 분석 97
• 5장 결론 105
• 참고문헌 108