Performance Analysis of Protocol Independent Multicasting-Dense Mode in Low Earth Orbit Satellite Networks

This research explored the implementation of Protocol Independent Multicasting - Dense Mode (PIM-DM) in a LEO satellite constellation. PIM-DM is a terrestrial protocol for distributing traffic efficiently between subscriber nodes by combining data streams into a tree-based structure, spreading from the root of the tree to the branches. Using this structure, a minimum number of connections are required to transfer data, decreasing the load on intermediate satellite routers. The PIM-DM protocol was developed for terrestrial systems and this research implemented an adaptation of this protocol in a satellite system. This research examined the PIM-DM performance characteristics which were compared to earlier work for On- Demand Multicast Routing Protocol (ODMRP) and Distance Vector Multicasting Routing Protocol (DVMRP) - all in a LEO satellite network environment. Experimental results show that PIM-DM is extremely scalable and has equivalent performance across diverse workloads. Three performance metrics are used to determine protocol performance in the dynamic LEO satellite environment, including Data-to- Overhead ratio, Received-to-Sent ratio, and End-to-End Delay. The OPNET® simulations show that the PIM-DM Data-to-Overhead ratio is approximately 80% and the protocol reliability is extremely high, achieving a Receive-to-Sent ratio of 99.98% across all loading levels. Finally, the PIM-DM protocol introduces minimal delay, exhibiting an average End-to-End Delay of approximately 76 ms; this is well within the time necessary to support real-time communications. Though fundamental differences between the DVMRP, ODMRP, and PIM-DM implementations precluded a direct comparison for each experiment, by comparing average values, PIM-DM generally provides equivalent or better performance

Controlo do transporte de sessões multicast em redes dinâmicas

Mestrado em Engenharia Electrónica e TelecomunicaçõesHoje em dia assiste-se a um aumento considerável da procura de serviços ou aplicações para múltiplos utilizadores (multiparty), como streaming de conteúdos media, partilha de informações, colaboração entre utilizadores, entre outros. O suporte de tais serviços pela Internet mostra-se extremamente exigente para as actuais arquitecturas de rede, requerendo recursos e funcionalidades completamente fora do alcance de serem suportadas. Desta forma, é necessário investigar e desenvolver novos mecanismos que possibilitem simultaneamente um melhor e maior controlo a este nível. Neste âmbito, tem-se observado actualmente um aumento no número de arquitecturas propostas, capazes de integrar as vantagens do protocolo IP multicast na entrega e transporte de conteúdos multimédia a grupos de utilizadores. Por outro lado, a inclusão de informação de contexto da rede, ambiente e utilizadores proporciona uma maior personalização e adaptação nas decisões de controlo necessárias à rede. É neste sentido que o projecto C-Cast abordado nesta tese se enquadra, procurando especificar uma arquitectura capaz de integrar uma quantidade abrangente de informação de contexto por forma a fornecer personalização nas sessões de entrega de conteúdos multimédia. Para a gestão dos recursos de rede é também proposto um mecanismo de transporte dos conteúdos baseado em IP multicast, juntamente com a possibilidade de adaptação dos caminhos escolhidos na rede de core baseada na informação de contexto da rede e do utilizador. A junção destes factores visa então possibilitar uma melhor gestão dos recursos disponibilizados pela rede. O principal objectivo desta Tese é então focado no desenvolvimento de um módulo inteligente, capaz de permitir o transporte multiparty e reserva de recursos, permitindo a entrega dos conteúdos de uma forma personalizada e independente das capacidades da rede e do utilizador, melhorando não só a qualidade de serviço, como também a qualidade de experiência. De forma a implementar a proposta apresentada, recorreu-se à criação de um novo componente organizado segundo uma arquitectura interna hierarquizada e centralizada, na qual um único módulo (IPT Controller) central comanda vários outros módulos (IPT Node) distribuídos ao longo de toda a rede. Após concluída a implementação, provou-se que o componente é capaz de criar e remover várias reservas de recursos por forma a permitir o transporte multiparty por caminhos específicos na rede. Este mecanismo é também capaz de modificar reservas previamente efectuadas, permitindo que as sessões multimédia sejam capazes de responder às modificações de contexto na rede, actualizando possíveis sessões já existentes com um mínimo de interrupção de serviço possível para utilizadores que não tenham sofrido alterações. Avaliando os resultados obtidos, pode-se também concluir que o impacto do IPT na rede é ligeiro e menor em relação ao dos restantes componentes, pelo que não é um factor decisivo no desempenho global da arquitectura.Today we are witnessing a considerable increase in the demand for services or applications for multiple users (multiparty), such as streaming media content, information sharing, collaboration among users, among others. The support of such services over the Internet proves to be extremely demanding for the existing network architectures, requiring features and functionality completely out of reach of the current networks. Thus, investigation and development of new mechanisms that enable a superior management at this level is necessary. In this context, it is possible to observe an increase in the number of architectures proposed, which are able of integrating the advantages of the IP multicast protocol in the transport and delivery of multimedia content to user groups. Moreover, the inclusion of context information from the network, environment and users, provides a greater customization and adaptation in the decisions necessary to control the network. It in this context that the C-CAST project discussed in this dissertation is included, which tries to specify an architecture capable of integrating a comprehensive amount of context information in order to be able to provide superior dynamic sessions to deliver multimedia content. For the management of the network resources, it is also proposed a mechanism for the transport of multimedia content based on IP multicast. The possibility of path adaptation in the core network based on context information of both users and network is also considered. Is it with the combination of these factors that this project seeks to enable an improved management of the network’s resources. The main objective of this dissertation is then focused on the latter point of the C-CAST project architecture. It proposed the development of an intelligent module capable of allowing multiparty transport and resource reservation, enabling the delivery of multimedia content in a personalized way, independent of network and users capabilities, improving not only the quality of service, as well as quality of experience. In order to implement the proposed solution, a new component was developed, organized according to a hierarchical and centralized architecture in which a single central unit (IPT Controller) is able to command several other modules (IPT Node) deployed throughout the network. It was verified that the developed component is capable of creating and removing the necessary enforcements on the network to enable the multiparty transport through specific data paths. It is also capable of modifying previous enforcements, allowing the multimedia sessions to adapt themselves to context changes avoiding as much as possible to disrupt the existing services to users that were not subjected to modifications. Evaluating the obtained results, it is possible to conclude that the overall impact of the IPT component in the network is reduced and considerably less than the one of the remaining components. Hence, the IPT does not have a direct impact on the overall architecture performance

IP Mobile Multicast over Next Generation Satellite Networks. Design and Evaluation of a Seamless Mobility Framework for IP Multicast Communications over a Multi-beam Geostationary Satellite Network

The inherent broadcast nature of satellites, their global coverage and direct access to a large number of subscribers give satellites unrivalled advantages in supporting IP multicast applications. A new generation of satellite systems that support regenerative on-board processors and multiple spot beam technology have opened new possibilities of implementing IP multicast communication over satellites. These new features enable satellites to make efficient use of their allocated bandwidth resources and provide cost effective network services but equally, create new challenges for mobile satellite terminals. IP mobility support in general and IP mobile multicast support in particular on mobile satellite terminals like the ones mounted on continental flights, maritime vessels, etc., still remain big challenges that have received very little attention from the research community. Up till now, there are no proposed mechanisms to support IP multicast for mobile receivers/sources in multi-beam satellite networks in open literature. This study explores the suitability of IP multicast mobility support schemes defined for terrestrial networks in a satellite environment and proposes novel schemes based on the concepts of Home and Remote subscription-based approaches, multiple interface and PMIPv6 protocol. Detailed analysis and comparison of results obtained from the proposed schemes, Mobile IP (MIP) Home and Remote subscription-based approaches (for terrestrial networks) when implemented on a reference multi-beam satellite network are presented. From these results, the proposed schemes outperform the MIP Home and Remote subscription-based approaches in terms of gateway handover latency, number of multicast packets lost and signalling cost over the satellite air interface

Supporting IP Multicast for Mobile Hosts

IP Multicast is an efficient mechanism of delivering a large amount of data to a group of members over the Internet. Link sharing is achieved by a multicast tree that connects all group members. Mobile IP is the proposed standard for IP mobility support and provides two schemes for mobile hosts to receive multicast packets, either through tunneling from the home agent (called home subscription) or by joining multicast groups in the visited foreign network (called remote subscription). The former compromises the link sharing of IP Multicast and uses sub-optimal routing, while the latter requires the foreign agent to be a multicast router and may incur frequent modifications of multicast trees due to mobile hosts. This paper introduces multicast agents for IP Multicast to mobile hosts. A multicast agent is a multicast router that serves multiple (foreign) networks. A foreign agent in the service area of a multicast agent notifies the multicast agent of the multicast groups that visiting ..

Mobility Management and Bandwidth Control of Multimedia Multicast in Wireless Network

無線網路技術的蓬勃發展為未來的網路使用帶來了新的契機和服務模式，且隨著技術的進步普及於生活中。而各種不同的應用也逐漸由有線網路移植到無線網路的環境上，在這當中，即時多媒體應用如：線上電影及音樂、線上會議……等更是不可避免的趨勢。 為了有效率地使用無線網路的頻寬並減少不必要的浪費，利用多點傳播（Multicast）和網際網路群組管理IGMP來傳輸頻寬需求較大的多媒體串流，在未來將是不可或缺的技術，然而，如同釵h網路協定一般，欲在無線網路的環境中使用，皆會面臨了使用者之行動管理和網路頻寬控制二大議題。 在本論文中，提出了新的架構和新的M&M（Mobile and Multicast）協定，其整合了802.11f IAPP，並且只需在AP上實作。在新的架構下，使用者可在intra-subnet及inter-subnet的環境下做handoff時，藉由AP間彼此交換訊息，減少多點傳播資料串流的中斷，讓使用者能繼續享有高品質的服務。除此之外，本論文亦利用訊息交換的機制，保留了服務品質保證（Quality of Service, QoS）參數傳遞的空間，讓未來針對QoS議題所提出的相關研究，能利用該參數的傳遞，加速頻寬的管理與控制（如預先頻寬保留、進入野i控制……等），以提供如多媒體串流等服務的品質保證。 最後，本論文所提的架構能和目前網路上的協定如IGMP、Mobile IP及IAPP等共存，而不需要加以更改，以提供一簡單、具有彈性且容易實作的新架構。With the advent of wireless and mobile technology, wireless communication is becoming more and more popular in human life. Moreover, real-time multimedia services like music and movies will indeed become important applications in wireless network. In order to achieve higher bandwidth utilization and reduce unnecessary bandwidth waste, using multicast and IGMP to deliver high bandwidth required multimedia stream would be a trend in the future. However, they also face two important issues when used in wireless network: user mobility management and bandwidth control. We propose a new protocol called M&M (mobile and multicast) protocol to support mobile multicast of multimedia content delivery service in wireless LANs. It is an extension of the IEEE 802.11f Inter-Access Point Protocol (IAPP) protocols and is intended to be implemented in access points. Under the new architecture, users can enjoy multimedia streaming service without interruption when roaming between APs in wireless access networks. The proposed M&M protocol supports both Intra-subnet and Inter-subnet roaming. Moreover, the proposed protocol supports the exchange of the QoS parameters of user’s subscribed service between APs to assure quality of service of the multimedia content delivery. Our protocol interworks with existing IGMP and Mobile IP as well IEEE 802.11 IAPP without modification. It is simple, flexible, and easy to implement.謝詞 三 論文摘要 四 THESIS ABSTRACT 五 目錄 六 表次 八 圖次 九 第一章 緒論 1 第一節 研究動機 1 第二節 研究目的 4 第三節 論文架構 6 第二章 文獻探討 7 第一節 網際網路群組管理協定（IGMP） 7 第二節 IAPP (INTER-ACCESS POINT PROTOCOL) 10 第三節 無線多點傳播之行動管理 12 2.3.1 IETF Mobile IP所建議之多點傳播管理 13 2.3.2 Mobile Multicast (MoM) Protocol：Multicast Support for Mobile Host 15 2.3.3 MobiCast：A Multicast Scheme for Wireless Networks 16 2.3.4 Supporting IP Multicast for Mobile Hosts 19 2.3.5 小結 20 第四節 無線多點傳播之安全議題 22 第三章 行動管理與頻寬控制 24 第一節 設計理念與目標 24 第二節 系統架構與方法描述 28 3.2.1 Intra-Subnet之多點傳播串流行動管理及頻寬控制 29 3.2.2 Inter-Subnet間之多點傳播串流行動管理及頻寬控制 32 3.2.3 Mobile Multicast（M&M）Control Message 34 第四章 系統實作 37 第一節 程式架構 37 第二節 MULTICAST FILTER的實作 40 4.2.1 Implementation Details of Multicast Filter 42 第三節 IAPP MODULE之實作 47 第四節 M&M MODULE之實作 50 第五節 小結 52 第五章 結論 53 參考文獻 5