The principle of universal shipborne automatic identification system (AIS) is to allow automatic exchange of shipboard information between one vessel and another. Saab TransponderTech AB has an operating AIS transponder on the market and the purpose of this report is to investigate alternative technologies that could result in a highly integrated replacement for the existing hardware. Design aspects of a system-on-chip are discussed, such as: available system-on- chip technologies, intellectual property, on-chip bus structures and development tools. This information is applied to the existing hardware and the integration possibilities of the various parts of the AIS transponder is investigated. The focus will be on two main transponder parts that are possible to replace with highly integrated circuits. The first of these parts is the so-called digital part where system-on-chip platforms for different technologies have been investigated with a special interest in a highly integrated FPGA implementation. The second part is the radio frequency receivers where alternatives to the existing superheterodyne receiver are discussed. The conclusion drawn is that there exist technologies for developing a highly integrated AIS transponder. An attractive highly integrated transponder could consist of a FPGA system-on-chip platform with subsampling digital receivers and additional components that are unsuitable for integration.

Emerging wireless networks are characterized by increased heterogeneity in wireless access technologies as well as increased peer-to-peer communication among wireless hosts. The heterogeneity among wireless access interfaces mainly exists because of the fact that different wireless technologies deliver different performance trade-offs. Further, more and more infrastructure-less wireless networks such as ad-hoc networks are emerging to address several application scenarios including military and disaster recovery. These infrastructure-less wireless networks are characterized by the peer-to-peer communication model. In this thesis, we propose transport protocols that tackle the challenges that arise due to the above-mentioned properties of state-of-the-art wireless data networks. The main contributions of this work are as follows: 1. We determine the ideal nature and granularity of transport adaptation for efficient operation in heterogeneous wireless data networks by performing comprehensive experimental analysis. We then design and implement a runtime adaptive transport framework, *TP, which accommodates the capabilities of the ideal transport adaptation solution. 2. We prove that conversational transport protocols are not efficient under peer-to-peer wireless data networks. We then design and implement NCTP which is a non-conversational transport protocol.

This thesis attempts to analyze a part of the big and complex process of how intellectual property ownership and technological innovation influence the performance of firms and their revenues. Here I analyze a firm's stock market performance as a function of the quantity and quality of intellectual property (patents) owned by the firm in context of the three US high-technology sectors, Pharmaceuticals, Semiconductors and Wireless. In these sectors, value of a firm is predominantly driven by the technologies which a firm owns. I use citation based indicators and number of claims to measure the quality of patents. This research presents empirical evidence for the hypothesis that in high-tech sectors, companies which generate better quality intellectual property perform better than average in the stock market. I also posit that firms which are producing better quality technologies (good R&D) invest more in R&D regardless of their market performance. Furthermore, though smaller firms get relatively less returns on quality and quantity of innovation, they tend to invest a bigger fraction of their total assets in R&D when they are generating high quality patents. Larger firms enjoy the super-additivity effects in terms of market performance as the same intellectual property gives better returns to them. In addition, returns to R&D are relatively higher in the pharmaceutical industry than semiconductor or wireless industries.

Internet Access logs in a local area network are the most prominent records when the source of an Internet event is traced back. Especially in a case where an illegal activity having originated from your local area network is of concern, it is highly desirable to provide healthy records to the court including the source user and machine identity of the log record in question. To establish the validity of user and machine identity in the log records is known as source authentication. In our study, after the problem of source authentication in each layer is discussed in detail, we argue that the only way to establish a secure source authentication is to implement a system model that unifies low level and upper level defense mechanisms. Hence, in this thesis we propose an Unauthorized Internet Access Blocking System validating the Source Information in Internet Access Logs. The first version of our proposed system, UNIDES, is a proxy based system incorporating advanced switches and mostly deals with the low level source authentication problems. In the second version, we extend our system with SIACS which is an Internet access control system that deals with the user level source authentication problems. By supplementing the classical username-password authentication mechanism with SSL client authentication, SIACS integrates a robust user level authentication scheme into the proposed solution.

The problem of providing Quality of Service (QoS) in the Internet has been an extremely active area of research and various mechanisms have been proposed related to this subject. Developing network applications have requirements such as bounded delay, jitter, minimum bandwidth and maximum loss rate. There is also a need to support large bandwidth networks because of growing link speeds. Previous QoS efforts did not fully satisfy all these needs of future networks but more recent approaches aim to be both scalable and rich in the provision of guaranteed services. Consequently core-stateless systems received much attention in recent years because of their scalability in supporting per-flow QoS. The property of not maintaining any per-flow state in the core routers is known as being core-stateless. In this thesis study, the need for core-stateless network architectures is pointed out and a literature survey about these schemes is carried out. Core-Stateless Guaranteed Fair (CSGF) network architecture, which provides deterministic fairness guarantees in a work-conserving manner, is selected and evaluated. Simulation studies about stateful Virtual Clock (VC) algorithm and CSGF&rsquo / s sub-protocols Core-Stateless Virtual Clock (CSVC), Core-Stateless Guaranteed Throughput (CSGT) and Core-Stateless Guaranteed Fairness (CSGF) are presented. Finally, the deficiencies in fairness of CSGF are demonstrated.

A substantial increase in the number of internet users and the traffic volume bring new challenges for network router design. The current routers need to support higher link data rates and large number of line cards to accommodate the growth of the internet traffic, which necessitate an increase in physical space, power and memory use. Packet forwarding, which is one of the major tasks of a router, has been a performance bottleneck in internet infrastructure. In general, most of the packet forwarding algorithms are implemented in software. However, hardware based solutions has also been popular in recent years because of their high throughput performance. Besides throughput, memory efficiency, incremental/dynamic updates and power consumption are the basic performance challenges for packet forwarding architectures. Hardware-based packet forwarding engines for network routers can be categorized into two groups that are ternary content addressable memory (TCAM) based and dynamic/static random access memory (DRAM/SRAM) based solutions. TCAM-based architectures are simple and hence popular solutions for today&rsquo / s routers. However, they are expensive, power-hungry, and oer little adaptability to new addressing and routing protocols. On the other hand, SRAM has higher density, lower power consumption, and higher speed. The common data structure used in SRAM-based solutions for performing longest prefix matching (LPM) is some type of a tree. In these solutions, multiple memory accesses are required to find the longest matched prefix. Therefore, parallel and pipelining techniques are used to improve the throughput. This thesis studies TCAM and SRAM based parallel and pipelined architectures for high performance packet forwarding. We proposed to use a memory efficient disjoint prefix set algorithm on TCAM based parallel IP packet forwarding engine to improve its performance. As a fundamental contribution of this thesis, we designed an SRAM based parallel, intersecting and variable length multi-pipeline array structure (SAFIL) for trie-based internet protocol (IP) lookup. We also proposed a novel dual port SRAM based high throughput IP lookup engine (SAFILD) which is built upon SAFIL. As an alternative to traditional binary trie, we proposed a memory efficient data structure called compact clustered trie (CCT) for IP lookup. Furthermore, we developed a novel combined length-infix pipelined search (CLIPS) architecture for high performance IPv4/v6 lookup on FPGA. Finally, we designed a memory efficient clustered hierarchical search structure (CHSS) for packet classification. A linear pipelined SRAM-based architecture for CHSS which is implemented on FPGA is also proposed.

The most studies on ad hoc network mainly focus on TCP (Transmission Control Protocol) of transport layer, the routing of network layer, multi-hop of Data-link layer, and the integration of WWAN and WLAN to increase the load balancing, coverage, and power savings. Nevertheless, in this dissertation, the system performances of four schemes proposed are improved with respect to data-link and network layers. One purpose of the data link layer is to perform error correction or detection. The other is responsible for the way in which different users share the transmission medium. The Medium Access Control (MAC) sublayer is responsible for allowing frames to be sent over the shared media without undue interference with other users. This aspect is referred to as multi-access communications. In the first and third schemes, the FDMA (Frequently-division multiple access) is employed to improve system performance, while in the fourth scheme the CDMA (Code-division multiple access) is used to enhance performance. Network layer has several functions, first is to determine the routing information. A second function is to determine the quality of service. A third function is flow control to avoid network to become congested. In the third scheme, the data-link and network layers have been used to increase system performance. Furthermore, the second scheme mainly concentrates on power savings under wireless sensor network. In ad hoc wireless networks, most data delivery is accomplished through multi-hop routing (hop by hop). This approach may leads to long delay and routing overhead regardless of which routing protocol is used. To overcome this inherent characteristic, this work presents a novel idea adopting dual-card-mode and performing self-organization process with specific IP naming and channel assignment to form a hierarchical star-graph ad hoc network (HSG-ad hoc) which can not only expedite the data transmission but also eliminate the route discovery procedure during data transmission. Therefore, the overall network reliability and stability can be significantly improved. Simulation results show that the proposed approach achieves substantial improvements in terms of average end-to-end delay, throughput, and packet delivery ratio. In a large-scale wireless sensor network, a topology is needed to gather state-based data from sensor network and efficiently aggregate the data given the requirements of balanced load, minimal energy consumption and prolonged network lifetime. In this study, we proposed a ring-based hierarchical clustering scheme (RHC) consisting of four phases: pre-deployment, parent-child relationship building, deployment, and member join phases. Two node types are distributed throughout the network: cluster head nodes (type 1 node) and general sensor nodes (type 2 node). The type 1 node has better battery life, software capability and hardware features than the type 2 node does; therefore, the type 1 node is a better cluster head than type 2 node. Most routing protocols focus mainly on obtaining a workable route without considering network traffic conditions for a mobile ad hoc network. Consequently, real time and multimedia applications do not achieve adequate quality of service (QoS). To support QoS, this work proposes a QoS-aware routing protocol, i.e. QUality of service with Admission control RouTing (QUART), that incorporates an admission control scheme into route discovery and route setup procedures. One variant of QUART, called, QUART-DD, adopts a dual-card dual-signal mechanism to increase system performance. Simulation results indicate that QUART-DD can significantly improve packet delivery ratio and throughput, while having a lower average end-to-end delay than routing protocols without QoS support. The performance of ad hoc wireless network suffers from problems in multi-hop transmission. This study adopts code division to modulate the frame header and the frame payload separately. A common spreading code modulates the frame header, and a special spreading code is negotiated and to modulate the frame payload. A field in the frame header indicates the spreading code used to modulate the successive frame payload. The modulated frame is transparent for every node, enabling many frames to be transmitted simultaneously. To allow the special spreading code negotiation, the RTS/CTS command is modified as ERTS/ECTS, and a spreading code table (SCT) is maintained in every node. Due to the space reuse, the proposed scheme has superior performance in latency and bandwidth utilization, as revealed by the simulation results.

The advent of Internet, the phone mobile and the globalization have modified the forms of communication in the world and the enterprises in general. All this has brought the search of facilities of communications permanents, mobilities and secures with quality of service to improve the Internet and the new aplications on devices mobile. The studies of the new protocol of internet as Ipv6 are in a proces that consist in finding new focus to improve the quality of service. This thesis consists in analyzing and give recomendations of Ipv6 with Business Intelligence to demonstrate that the use improve the management in the enterprises. Ipv6 is the best solution to improve the throughput in the network. The other side, it proposes a new way of business on internet y the born the new aplications as for example the m-commerce and Business Intelligence since any devices mobile.

<p>The most widely used protocol for providing reliable service and congestion control in the Internet is the Transmission Control Protocol (TCP). When the Internet is moving towards more use in mobile applications it is getting more important to know how TCP works for this purpose.</p><p>One of the technologies used for mobile Internet is the Enhanced General Packet Radio Service (EGPRS) extension to the popular GSM system. This thesis presents a low-level analysis of TCP performance in an EGPRS system and an overview of existing TCP, GSM and EGPRS technologies.</p><p>The bottleneck in an EGPRS system is the wireless link – the connection between the mobile phone and the GSM base station. The data transfer over the wireless link is mainly managed by the complex RLC/MAC protocol.</p><p>In this thesis, simulations were made to identify some problems with running TCP and RLC/MAC together. The simulations were made using existing EGPRS testing software together with a new TCP module. The simulation software is also briefly described in the thesis.</p><p>Additionaly, some suggestions are given in order to enhance performance, both by changing the EGPRS system and by modifying the TCP algorithms and parameters.</p>

Les réseaux de communication offrent à ce jour un ensemble de services très<br />diversifié aussi bien pour les industriels, les banques, la recherche, pour des particuliers et récemment<br />dans la médecine et la commande à distance. A cette forte utilisation des réseaux<br />viennent s'ajouter des contraintes de performances, de sécurité et de qualité de service que les<br />fournisseurs de service se doivent de respecter. L'étude des performances des réseaux ainsi que<br />leur modélisation exacte est donc un pas important pour la connaissance des influences des<br />différents liens des lignes de transmission sur les données qui les traversent. Afin d'évaluer l'in-<br />fluence des réseaux de communication dans la transmission des données, nous proposons de<br />modéliser puis d'étudier une ligne de transmission TCP/IP soumise aux protocoles de contrôle<br />de congestion et plongée dans un environnement Internet. L'outil de modélisation utilisé est les<br />RdP hybrides. Un modèle a été établi à base duquel toutes les dynamiques peuvent être observées<br />à tous les niveaux d'une communication (charge des buffers, baisse des vitesses à l'entrée<br />des routeurs, séparation des flux par les routeurs, priorités, stockage des données, retards, pertes,<br />etc.). Ce modèle détaillé nous a aussi permis de visualiser directement l'effet des changements<br />de paramètres de la ligne et des protocoles sur l'évolution de la transmission sur la ligne : Un<br />large panel de simulations a donc été effectué afin de visualiser ces différentes performances.<br />Enfin, un travail d'amélioration du temps de détection des pertes sur une ligne a été effectué.