by Fu Chengpeng. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2001. / Includes bibliographical references (p. 102-119). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Abstracts in English and Chinese.

In 3GPP Release 5 and beyond, an All-IP architecture has been specified. This indicates that convergence of mobile applications such as voice, video and gaming to IP is not a "trend" anymore, but a reality. IP mobility has therefore been intensively studied in recent years. Majority of the existing IP mobility schemes, including Mobile IPv6 (MIPv6), the current de facto standard solution for IP mobility, are designed around a two-tier addressing model. In this model, while visiting a foreign link, a mobile node (MN) is identified by its home address assigned by its home link but is located by the care-of-address (CoA) acquired from the foreign link. Incoming packets for the MN are routed to its home link as usual, but are intercepted by the home agent and tunneled to the CoA. This model is simple and is well accepted. However, when it comes to real-time applications, it also has been known to be ineffective in terms of handoff delay and bandwidth consumption due to, respectively, its lengthy CoA acquisition and the extra IP header for tunneling. The latter is especially expensive for the case of real-time applications because of the excessive overhead induced by the extra IP header (20 bytes for IPv4 and 40 bytes for IPv6) to the packet payload size (∼20-160 bytes). / In this thesis, we show that (i) can be overcome when a direct Layer-3 connection between the home and any particular visiting domain is available so that inter-domain routing effectively becomes routing within the same logical hierarchy. We call a global network formed by the directly Layer-3 connected domains the Global Universal Addressing (GUA) framework. When deployed on the GUA framework, the existing local mobility schemes can easily be upgraded to support global mobility as seamlessly as local mobility with no modification needed. / Much work has been devoted to improving the two-tier addressing model, including various local mobility schemes such as HAWAII and Cellular IP. These schemes eliminate the CoA acquisition when the MNs move within one domain, but revert back to the two-tier addressing model when the mobility is across different domains (or so-called global mobility). These schemes therefore inherit all the drawbacks of the two-tier addressing model when it comes to global mobility. It has been argued that mobility across domains is rare. However, looking into the near future, this assumption is certainly not applicable to the upcoming fourth-generation (4G) wireless architecture in which the MNs can dynamically choose the best connected wireless interface among heterogeneous networks (e.g., WiFi, WiMax, etc.) of different domains as they move. Therefore, an efficient solution is needed to handle the frequent inter-domain mobility, or global mobility, in the form of heterogeneous handoffs as well. / To address (ii), we propose a new IP mobility scheme called Cellular Universal IP (CUIP), which runs on the GUA framework and makes use of a home route concept also proposed in this thesis. The home route concept intelligently integrates the efficiency of prefix routing and flexibility of full-address routing to achieve high performance and routing scalability under the universal addressing model. In addition, based on IPv6, CUIP makes use of the IPv6 option header to embed the route-update information of an MN in the outgoing data packets for a short period after handoff, so that global routing information can be effectively updated along the path traversed by the packets. We study the performance of CUIP quantitatively and show the following: (1) the average number of routers updated per handoff is less than three, so that the average handoff delay is minimal. (2) The routing table complexity is asymptotically independent of the depth and monotonically decreasing with the width of the network hierarchy. That is, routing scalability is not a concern even in large networks. / To efficiently support global mobility, a universal addressing model, under which a mobile node is always identified and located by the same IP address globally, is an obvious answer to the problems associated with the two-tier addressing model. However, the universal addressing model has been considered to be infeasible due to difficulties in (i) inter-domain (or cross-prefix) IP routing and (ii) routing table scaling. / by Lam, Pak Kit. / "June 2007." / Adviser: Soung Liew. / Source: Dissertation Abstracts International, Volume: 69-01, Section: B, page: 0553. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references (p. 128-130). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.

A área de gerência de rede cresce à medida que redes mais seguras e menos vulneráveis são necessárias, e as aplicações que concorrem pelo seu uso, necessitam de alta disponibilidade e qualidade de serviço. Quando estamos focando a gerência da infra-estrutura física das redes de computadores, por exemplo, a taxa de uso de um segmento de rede, podemos dizer que esse tipo de gerenciamento encontra-se em um patamar bastante sedimentado e testado. Por outro lado, há ainda lacunas para pesquisar na área de gerenciamento de protocolos de alto nível. Entender o comportamento da rede como um todo, conhecer quais hosts mais se comunicam, quais aplicações geram mais tráfego e, baseado nessas estatísticas, gerar uma política para a distribuição de recursos levando em consideração as aplicações críticas é um dever nas redes atuais. O grupo de trabalho IETF RMON padronizou, em 1997, a MIB RMON2. Ela foi criada para permitir a monitoração de protocolos das camadas superiores (rede, transporte e aplicação), a qual é uma boa alternativa para realizar as tarefas de gerenciamento recém mencionadas. Outro problema para os gerentes de rede é a proliferação dos protocolos de alto nível e aplicações corporativas distribuídas. Devido a crescente quantidade de protocolos e aplicações sendo executados sobre as redes de computadores, os softwares de gerenciamento necessitam ser adaptados para serem capazes de gerenciá-los. Isso, atualmente, não é fácil porque é necessário usar linguagens de programação de baixo nível ou atualizar o firmware dos equipamentos de monitoração, como ocorre com os probes RMON2. Considerando este contexto, esse trabalho propõe o desenvolvimento de um agente RMON2 que contemple alguns grupos dessa MIB. O agente baseia-se na monitoração protocolos de alto nível e aplicações que são executados sobre o IP (Internet Protocol) e Ethernet (na camada de enlace). Além da implementação do agente, o trabalho apresenta um estudo de como obter estatísticas do agente RMON2 e usá-las efetivamente para gerenciar protocolos de alto nível e aplicações.

Dissertação (Mestrado em Engenharia Elétrica) - Centro Universitário da FEI, São Bernardo do Campo, 2014

Tese de mestrado integrado. Engenharia Electrotécnica e de Computadores. Faculdade de Engenharia. Universidade do Porto. 2008

Tese de mestrado integrado. Engenharia Electrotécnica e de Computadores (Major Telecomunicações). Faculdade de Engenharia. Universidade do Porto. 2009

This thesis examines the current implementations for the distribution of real-time GNSS data over IP networks such as the public Internet, focusing on two essential components of the system, data format and transport protocol. The provision of a suitable data format will allow users to take full advantage of the real-time GNSS data distribution system. Types of GNSS supported, message sizes, data rates, data precision levels, hardware and software support and possible future developments are investigated. An analysis is carried out on commonly known GNSS data formats, highlighting the most suitable standard for each evaluation criterion. A similar investigation is carried out on the transport protocols. An analysis is conducted on various design aspects of NTRIP and RT-IGS protocols, covering factors such as data latency, integrity, firewalls and proxy server compatibility and scalability. The analysis also covers the design aspects of the new draft Version 2 of NTRIP. The latter parts of this thesis report on the experiment results aimed at providing assessment of the current level of implementation of NTRIP. Data latency and integrity using NTRIP over the Internet are examined. Their impacts on users applications as the quality of real-time kinematic positioning is assessed. The results show that the performance of the system satisfies the rigorous requirement of the end-user application. The draft version of the new NTRIP indicates that UDP will be also supported. A similar investigation is carried out, providing the first experiment results on the new option. Tests using similar metrics, data latency and integrity, were carried out to verify the inherent differences between TCP and UDP. It was ascertained that, in most cases, UDP does offer improvement in terms of reduced latency over TCP. However this improvement is not significant enough to affect the performance of users applications tested. Compatibility tests were also carried out and the test results show that the new option experiences some compatibility issues with firewalls and wireless networks.

Detta examensarbete behandlar problemet med att testa inbyggda system i kontorsmiljö. För att göra detta och därigenom kunna göra anrop på det inbyggda systemets API, måste detta anrop skickas som ett seriellt datapaket över en seriell kommunikationslänk som TCP/IP. Detta möjliggjordes genom att först upprätta en kommunikationslänk med protokollet TCP/IP, där användningen av POSIX-sockets tillämpades. För att packa ner och packa upp funktionsanropen till seriell data implementerades ett protokoll som följdes när detta utfördes. Hantering av data i samband med överföring över TCP/IP sköttes av ett protokoll vid namn BGSFP, ett protokoll som bygger på det tidigare protokollet TSFP.

In recent years, the requirement for embedded controllers has been steadily on the increase due to the development of computers, communication ,WWW and consumers¡¦ products. Consequently, integration and application of the embedded system and the World-Wide Web become more and more important. The Web-based embedded system developed in this paper tends build a service of micro web server. By this service, users can not only receive the information from the system via the browser, but also design particular processes for themselves. Besides, the system developer can use the most popular tools to edit the page for the Web-based embedded system. This Web service technology offers an operational interface, which is user-friendly, and cost effective with the capability of cross-platform and TCP/IP transmission. The presented achievement is applied to temperature control system for performance evaluation of remote control.

Most process of lease is done manually in the past. Since the networks were used extensively and systems of Point of Sales risen quickly, the efficiency of administration of payment flow had been obviously promoted. What are mostly encrypted are information of payment flow, but what we encrypt is the information of leased products this time. We apply encryption technique to the lease system, and access information via RS-232 devices, such as SmartCard Reader and EM Reader. After processing of system and encryption, the system will transfer the processed data to the server. In this paper, we take Kaohsiung C-Bike Lease System for case study, our discussion will focus on network packet, data encryption, and real-time monitoring. We will also introduce critical features and mechanisms of the lease system and address some issues we encountered. This system encrypts data via Advanced Encryption Standard, sends out data packets via TCP/IP, and monitors leased bikes via databases and framework of multi-thread.