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1
Yang, Weilai. "Pricing Network Resources for Differentiated Service Networks." Diss., Georgia Institute of Technology, 2004. http://hdl.handle.net/1853/5227.
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We developed a price-based resource allocation scheme for Differentiated Service (DiffServ) data networks. The DiffServ framework was proposed to provide multiple QoS classes over IP networks. Since the provider supports multiple service classes, we need a differentiated pricing scheme, as supposed to the flat-rate scheme employed by the Internet service providers of today. Charging efficiently is a big issue. The utility of a client correlates to the amount of bandwidth allocated. One difficulty we face is that determining the appropriate amount of bandwidth to provision and allocate is problematic due to different time scales, multiple QoS classes and the unpredictable nature of users.
To approach this problem, we designed a pricing strategy for Admission Control and bandwidth assignment. Despite the variety of existing pricing strategies, the common theme is that the appropriate pricing policy rewards users for behaving in ways to improve the overall utilization and performance of the network. Among existing schemes, we chose auction because it is scalable, and efficiently and fairly shares resources. Our pricing model takes the system's availability and each customer's requirements as inputs and outputs the set of clients who are admitted into the network and their allocated resource. Each client proposes a desired bandwidth and a price that they are willing to pay for it. The service provider collects this information and produces parameters for each class of service they provide. This information is used to decide which customers to admit.
We proposed an optimal solution to the problem of maximizing the provider's revenue for the special case where there is only one bottleneck link in the network. Then for the generalized network, we resort to a simple but effective heuristic method. We validate both the optimal solution and the heuristic algorithm with simulations driven by a real traffic scenario. Finally, we allow customers to bid on the duration for which the service is needed. Then we study the performance of those heuristic algorithms in this new setting and propose possible improvements.
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Bhatti, Atif, and Imran Aslam Choudhary. "Service Discovery for Future Mobile Services." Thesis, Norwegian University of Science and Technology, Department of Telematics, 2010. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-10900.
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The pervasive computing environment for heterogeneous network is on a continuous rise. The ability to interact and control network devices with different functionalities within office and home environment could be very beneficial to a lot of users. The service discovery in computers and mobile devices enabled them to interact with one another through wireless and heterogeneous wired networks. Services advertise their existence in a dynamic way and devices are designed with this capability to discover these services and its properties automatically. These devices are though based on different technologies but are still able to communicate and discover one another based on existing service discovery architectures. It is notable that a significant number of networked devices are now mobile and these mobile devices make service discovery more challenging.In future mobile multi-domain multi-language environments, a service can be anything and introduced by anybody. Consequently, same or equivalent services may have different names and services with same name or type may be completely different. Existing service discovery systems are incapable of handling these situations. We have implemented a service discovery system which supports semantics to service descriptions. It allows any user to act as a service provider and introduce any service at any time. The service provider can define any service as equivalent to any existing service and in any language as wanted. In addition, it is capable to find services that are not exact matches of the requested ones. More semantics are introduced through attributes like EquivalenceClass, ParentType and Keywords. The test conducted on this system in real time proves that the system is efficient and can be applied in real life.
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Valancius, Vytautas. "Wide-area route control for online services." Diss., Georgia Institute of Technology, 2012. http://hdl.handle.net/1853/43623.
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Accelerated by on-demand computing, the number and diversity of the
Internet services is increasing. Such online services often have unique
requirements for the underlying wide-area network: For instance, online
gaming service might benefit from low delay and jitter paths to client,
while online data backup service might benefit from cheaper paths.
Unfortunately, today's Internet does not accommodate fine-grained,
service-specific wide-area route control. In this dissertation, I achieve
the following goals: 1) improve the access to the routes, 2) quantify
the benefits of fine-grained route control, and 3) evaluate the
efficiency of current payment schemes for the wide-area routes.
* Improving access to wide-area route control. Online services
face significant technological and procedural hurdles in
accessing the routes: Each service in need to control the Internet
routes, has to obtain own equipment, Internet numbered resources, and
establish contracts with upstream ISPs. In this dissertation, I propose
and describe implementation and deployment of a secure and scalable
system which provides on-demand access to the Internet routes. In
setting such as cloud data center, the system can support multiple
online services, providing each service with an illusion of direct
connectivity to the neighboring Internet networks, which, for all
practical purposes, allows services to participate fully in the
Internet routing.
* Quantifying the benefits of fine-grained route control. Even
if online services are presented with wide-area route choice, it is not
clear how much tangible benefit such choice provides. Most modern Online
Service Providers (OSP) rely primarily on the content routing to
improve network performance between the clients and the replicas. In
this dissertation, I quantify the potential benefit the OSPs can gain if
they perform a joint network and content routing. Among other findings,
I find that by performing joint content and network routing, OSPs can
achieve 22% larger latency reduction than can be obtained by content
routing alone.
* Modeling and evaluating the efficiency of the current payment
schemes for wide-area routes. Finally, increasing diversity and
sophistication of the online services participating in the Internet
routing poses a challenge to payment models used in today's
Internet. Service providers today charge business customers a blended
rate: a single, "average" price for unit of bandwidth, without regard
to cost or value of individual customer's flows. In my dissertation, I
set to understand how efficient this payment model is and if more
granular payment model, accounting for the cost and value of different
flows could increase the ISP profit and the consumer surplus. I develop
an econometric demand and cost model and map three real-world ISP data
sets to it. I find that ISPs can indeed improve the economic efficiency
with just a few pricing tiers.
4
Kulkarni, Parag Gopal. "Lightweight Mechanisms for Quality of Service Management in Differentiated Services Networks." Thesis, Ulster University, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.487652.
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Ever since applications requiring different types of service (e.g. low loss, high throughput, low delay/jitter etc.) emerged, there has been a need to support service differentiation Le. differentiation based on the Quality of Service (QoS). Two key solutions to the QoS problem have emerged - Integrated Services (IntServ), which provide fine grained QoS on a per flow basis and Differentiated Services (DiffSelv), which provide coarse grained QoS on a traffic aggregate basis. DiffServ seems to be winning the battle so far because it is simple and scalable. In the DiffServ architecture, the edge routers measure traffic for each Service Level Agreement (SLA) and classify it (traffic classified by the edge router will henceforth be referred to as DS marked) into one of the service classes. The core routers on the other hand, on receipt of a DS marked packet, forward it onto the next hop according to a 'Per Hop Behaviour' (PHB) where a PHB corresponds to a traffic class. Even though the IETF DiffServ \Vorking Group has standardized a few PHBs such as the Expedited Forwarding (EF) PHB and Assured Forwarding (AF) PHB, it has not mandated any specific mechanisms to realize these. This thesis proposes lightweight mechanisms to address the requirements within these two PHBs.
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Avgeropoulos, Konstantinos. "Service Policy Management for User-Centric Services in Heterogeneous Mobile Networks." Thesis, KTH, Mikroelektronik och Informationsteknik, IMIT, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-93043.
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The Session Initiation Protocol (SIP) is a signaling protocol for IP-based media services that will be the de facto standard for future media-over-IP services. Since SIP User Agents (UAs) support a limited number of service types (usually one or two), we assume that the future user will need to operate several UAs simultaneously. These UAs will constitute the user's personal service network. In this thesis, we investigate architectures for policy-based management of this network so that it can be used in an efficient manner. To achieve this, we propose a new SIP entity, called the SIP Service Manager (SSM), which lies in the core of the management system. Finally, we evaluate our proposal by implementing one version of the SIP Service Manager.Session Initiation Protocol (SIP) är ett signaleringsprotokoll för IP-baserade mediatjänster som kommer att bli "de facto"-standard för framtida "media-över-IP"-tjänster. Då SIP User Agents (UAs) stöder ett begränsat antal typer av tjänster (oftast en eller två), antar vi att framtida användare kommer att behöva använda sig av flera UAs samtidigt. Dessa UAs utgör en användares personliga tjänstenätverk. I denna rapport, undersöker vi arkitekturer för policybaserad hantering (management) av detta nätverk, så att det kan användas effektivt. För att uppnå detta, föreslår vi en ny SIP-enhet, kallad SIP Service Manager (SSM), som är placerad i kärnan av hanteringssystemet. Slutligen utvärderar vi vår föreslagna lösning genom att implementera en version av en SIP Service Manager.
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Liang, Liang. "The impact of innovation networks on service design." Thesis, University of Exeter, 2016. http://hdl.handle.net/10871/28036.
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Innovation networks are not only about connections, but also dynamics, structures and influences. This research focuses on these three new aspects of innovation networks. The results of this research show that innovation networks have regularities in their dynamics, structures and influences. In the conclusion, these regularities are presented in the network snapshots and regression modelling. This research makes contributions in improving the understanding about how service innovation is created.
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Taneja, Mukesh. "A service curve approach for quality of service management in integrated services networks /." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 1998. http://wwwlib.umi.com/cr/ucsd/fullcit?p9914079.
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Régnier, Jean Michel. "Priority assignment in integrated services networks." Thesis, Massachusetts Institute of Technology, 1986. http://hdl.handle.net/1721.1/15076.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1986.MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING
Bibliography: leaves 139-141.
by Jean Michel Régnier.
Ph.D.
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Gingold, David. "Integrated digital services for cable networks." Thesis, Massachusetts Institute of Technology, 1996. http://hdl.handle.net/1721.1/10650.
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Morrar, Rabeh. "Public-private innovation networks in services." Thesis, Lille 1, 2011. http://www.theses.fr/2011LIL12005/document.
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En s’appuyant sur une réflexion théorique et une investigation empirique, cette thèse cherche à montrer que les Réseaux d’Innovation, surtout quand ils combinent les acteurs publics et privés, constituent à la fois un concept théorique important et une réalité économique croissante dans le secteur des services. Dans la partie théorique, nous développons un cadre conceptuel qui décrit le processus d’innovation des Réseaux d'Innovation Public-Privé dans le secteur des services (ServRIPP). L’innovation est produite à travers la mise en œuvre de mécanismes de coordination entre les quatre éléments suivants du cadre conceptuel : 1) l’inclusion des acteurs publics et privés, 2) le processus dynamique des interactions entre les réseaux d’acteurs, 3) l’existence des liens sociaux, et 4) un modèle dynamique des cycles de vie des réseaux d’innovation. Ce cadre conceptuel tient compte des différences entre ServRIPP et des types d’innovations qui leur sont associés. Dans la partie empirique, nous mobilisons tout d’abord le cas de Lyonbiopole afin d’analyser les processus d’innovation dans le cadre d’un ServRIPP de santé. Ensuite, nous utilisons les données françaises de la 4ème enquête communautaire sur l’innovation (CIS 4) pour tester l’effet des coopérations public-privé sur les performances d’innovationUsing both a theoretical discussion and an empirical illustration, this work shows that the INs, especially when they combine public and private service actors, are both a very important theoretical concept and a rising economic reality in service sectors. In the theoretical discussion, we develop a conceptual framework which describes the innovation process in the public-private innovation network in services (ServPPINs). The innovation is produced through the coordination mechanism between the four components of the framework: 1) the inclusion of public and private actors; 2) the dynamic process of interactions between network actors; 3) the existence of social relationships; 4) a network life cycle growth model. This conceptual framework considers the differences in the ServPPINs and their associated innovation output. In the empirical analysis, we employ Lyonbiopole as a case study to describe the innovation process under the conceptual framework of ServPPINs. Also, using French CIS 4 data, we test the effect of cooperation between public and private sectors (ServPPINs) on innovation output
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Serbest, Yetik. "Resource management of integrated services networks /." Digital version accessible at:, 2000. http://wwwlib.umi.com/cr/utexas/main.
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Aktop, Baris. "A framework for maximizing the survivability of network dependent services." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2003. http://library.nps.navy.mil/uhtbin/hyperion-image/02Mar%5FAktop.pdf.
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Demirci, Mehmet. "Facilitating the provision of auxiliary support services for overlay networks." Diss., Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/49089.
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Network virtualization and overlay networks have emerged as powerful tools for improving the flexibility of the Internet. Overlays are used to provide a wide range of useful services in today's networking environment, and they are also viewed as important building blocks for an agile and evolvable future Internet. Regardless of the specific service it provides, an overlay needs assistance in several areas in order to perform properly throughout its existence.
This dissertation focuses on the mechanisms underlying the provision of auxiliary support services that perform control and management functions for overlays, such as overlay assignment, resource allocation, overlay monitoring and diagnosis. The priorities and objectives in the design of such mechanisms depend on network conditions and the virtualization environment. We identify opportunities for improvements that can help provide auxiliary services more effectively at different overlay life stages and under varying assumptions.
The contributions of this dissertation are the following:
1. An overlay assignment algorithm designed to improve an overlay's diagnosability, which is defined as its property to allow accurate and low-cost fault diagnosis. The main idea is to increase meaningful sharing between overlay links in a controlled manner in order to help localize faults correctly with less effort.
2. A novel definition of bandwidth allocation fairness in the presence of multiple resource sharing overlays, and a routing optimization technique to improve fairness and the satisfaction of overlays. Evaluation analyzes the characteristics of different fair allocation algorithms, and suggests that eliminating bottlenecks via custom routing can be an effective way to improve fairness.
3. An optimization solution to minimize the total cost of monitoring an overlay by determining the optimal mix of overlay and native links to monitor, and an analysis of the effect of topological properties on monitoring cost and the composition of the optimal mix of monitored links. We call our approach multi-layer monitoring and show that it is a flexible approach producing minimal-cost solutions with low errors.
4. A study of virtual network embedding in software defined networks (SDNs), identifying the challenges and opportunities for embedding in the SDN environment, and presenting two VN embedding techniques and their evaluation. One objective is to balance the stress on substrate components, and the other is to minimize the delays between VN controllers and switches. Each technique optimizes embedding for one objective while keeping the other within bounds.
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Al, Ridhawi Yousif. "Dynamic Composition of Service Specific Overlay Networks." Thèse, Université d'Ottawa / University of Ottawa, 2013. http://hdl.handle.net/10393/24011.
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Content delivery through service overlay networks has gained popularity due to the overlays’ abilities to provide effective and reliable services. Inefficiencies of one-to-one matching of user requirements to a single service have given rise to service composition. Customized media delivery can be achieved through dynamic compositions of Service Specific Overlay Networks (SSONs). However, the presence of SSONs in dynamic environments raises the possibility of unexpected failures and quality degradations. Thus constructing, managing, and repairing corrupted service paths are challenging dilemmas. This thesis investigates the problem of autonomous SSON construction and management and identifies the drawbacks of current approaches.
A novel multi-layered, autonomous, self-adaptive framework for constructing SSONs is presented. The framework includes a Hybrid Service Overlay Network layer (H-SON). The H-SON is a dynamic hybrid overlay dedicated to service composition for multimedia delivery in dynamic networks. Node placement in the overlay depends on the node’s stability, types and quality of provided services. Changes in stability and QoS of service nodes are reflected by dynamic re-organizations of the overlay. The H-SON permits fast and efficient searches for component services that meet client functional and quality expectations.
Self-managed overlay nodes coordinate their behaviors to formulate a service composition path that meets the client’s requirements. Two approaches are presented in this work. The first illustrates how SSONs are established through dynamically adaptable MS-designed plans. The imprecise nature of nonfunctional service characteristics, such as QoS, is modeled using a fuzzy logic system. Moreover, semantic similarity evaluations enable us to include, in compositions, those services whose operations match, semantically, the requirements of the composition plan.
Plan-based composition solutions restrict service discovery to defined abstract models. Our second composition approach introduces a semantic similarity and nearness SSON composition method. The objective is to free service nodes from the adherence to restrictive composition plans. The presented work illustrates a service composition solution that semantically advances service composition paths towards meeting users’ needs with each service hop while simultaneously guaranteeing user-acceptable QoS levels.
Simulation results showcase the effectiveness of the presented work. Gathered results validate the success of our service composition methods while meeting user requirements.
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Cardoso, Tiago Oliveira Machado de Figueiredo. "Proactive services ecosystem framework." Doctoral thesis, Faculdade de Ciências e Tecnologia, 2011. http://hdl.handle.net/10362/7499.
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Dissertation presented to obtain the degree of
Doctor in Electrical and Computer Engineering, specialization on Collaborative Enterprise NetworksCollaborative-Networks (CN) have experienced a fast evolution in the last two decades. The collaboration among independent entities or professionals supported by Information and Communication Technology (ICT) has attracted the research community to establish the conceptual basis for this scientific discipline. Service Orientation has been one of the key selected paradigms for that conceptual basis. Nevertheless, the service concept itself does not have a common understanding in the Business and ICT worlds. In the former, client satisfaction, resources management and business process models are some example concerns, whilst the later deals with interoperability, remote function calling or communication protocols. If for example an enterprise provides some service, it may hire specialists to wrap such service into web-services, expecting to reach worldwide potential new clients. In fact, nowadays Web Services and Service Oriented Architectures (SOA) are the technological elements most commonly used. However, these are passive elements in the sense they do not perform any action towards pursuing business interests, which constitute a limiting factor from a business perspective. Another approach for the above mentioned enterprise is to follow the Multi-Agent Systems (MAS) approach, as the pro-activity is a keyword in such contexts. Nevertheless, as MAS approaches are not so commonly used and not so robust yet, the worldwide potential set of new clients is reduced; which also constitutes an inhibitor factor from the business perspective. This dissertation proposes a Pro-Active Services Ecosystem Framework, gathering inspiration from both the SOA and MAS research areas, trying to bridge the business and ICT worlds through the base concepts for the creation of a Services’ Ecosystem where business services are represented in a pro-active manner towards pursuing business interests, like finding collaboration opportunities or improving the chances each CN member has to see its services selected among competitors, for example. This work also includes a prototype system applied / validated in the area of a Professional Virtual Community of Senior Professionals.
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Braun, Matthew J. "A method for mitigating denial of service attacks on differentiated services networks." Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2002. http://library.nps.navy.mil/uhtbin/hyperion-image/02sep%5FBraun.pdf.
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Li, Shu-leung Sammy. "The evolving internet services industry in HK : strategic management on changes and service innovation /." Hong Kong : University of Hong Kong, 1997. http://sunzi.lib.hku.hk/hkuto/record.jsp?B18831308.
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Bonada, i. Cruells Eduard. "Building ethernet connectivity services for provider networks." Doctoral thesis, Universitat Pompeu Fabra, 2012. http://hdl.handle.net/10803/85413.
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Network providers are motivated to deploy Ethernet in their infrastructures. However, this represents a new application for Ethernet technology that leads to new requirements. In Ethernet networks, the Rapid Spanning Tree Protocol (RSTP) creates an active tree on top of the physical topology to avoid potential loops and allows the bridge functionalities to work properly. However, there are some implications of using RSTP to prune the physical topology into an active tree: unused links and sub-optimal paths. In addition, RSTP suffers count-to-infinity and takes too long to recover from critical failures. In this thesis we propose a complete solution based on RSTP extensions that addresses the shortcomings. We design and evaluate two extensions: RSTP-Conf to provide quick recoveries and RSTP-SP to operate with optimal path communications.Els proveïdors de xarxa estan motivats per implementar Ethernet en les seves infraestructures. No obstant, això representa una nova aplicació per Ethernet que comporta nous requeriments. En les xarxes Ethernet, el protocol de Rapid Spanning Tree (RSTP) crea un arbre actiu per evitar cicles i permetre que les xarxes Ethernet funcionin correctament. Hi ha però algunes implicacions de l'ús de RSTP per transformar la topologia física en un arbre actiu: alguns enllaços no utilitzats i la creació de rutes sub-òptimes. A més, RSTP pateix count-to-infinity i tarda massa temps per recuperar-se de caigudes crítiques. En aquesta tesi es proposa una solució completa basada en extensions d’RSTP que aborda les seves deficiències. Dissenyem i avaluem dues extensions: RSTP-Conf per proporcionar una ràpida recuperació i RSTP-SP per operar amb comunicacions per camins òptims.
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Wright, Roger E. "Management System for Heterogeneous Networks security services." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1998. http://handle.dtic.mil/100.2/ADA349548.
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Thesis (M.S. in Systems Technology (Command, Control and Communications)) Naval Postgraduate School, June 1998."June 1998." Thesis advisor(s): Cynthia E. Irvine. Includes bibliographical references (p. 261-263). Also available online.
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Guerreiro, João. "Secure Web Services for Wireless Sensor Networks." Thesis, Uppsala University, Department of Information Technology, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-129474.
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Sensor deployments are becoming more and more common nowadays and the ways to access them are becoming more standardized. Indeed, users want to access sensor data via the Internet and without using some complex and unknown protocol; enter Web Services. By observing the typical system architecture for relaying sensor information to the web, we identified out of a large group of security issues a particular one. The issue in question is user privacy.
In this thesis we focus on hiding the activity of a user who queries a sensor deployment, from an attacker that can listen to communications in the neighborhood of the network. Our goal is to generate extra traffic in an intelligent way so that it can effectively mask user activity without draining the energy from the sensors.
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Cao, Guangtong. "Distributed services for mobile ad hoc networks." Texas A&M University, 2005. http://hdl.handle.net/1969.1/2541.
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A mobile ad hoc network consists of certain nodes that communicate only
through wireless medium and can move arbitrarily. The key feature of a mobile ad
hoc network is the mobility of the nodes. Because of the mobility, communication
links form and disappear as nodes come into and go out of each other's communica-
tion range. Mobile ad hoc networks are particularly useful in situations like disaster
recovery and search, military operations, etc. Research on mobile ad hoc networks
has drawn a huge amount of attention recently. The main challenges for mobile ad
hoc networks are the sparse resources and frequent mobility. Most of the research
work has been focused on the MAC and routing layer. In this work, we focus on
distributed services for mobile ad hoc networks. These services will provide some
fundamental functions in developing various applications for mobile ad hoc networks.
In particular, we focus on the clock synchronization, connected dominating set, and
k-mutual exclusion problems in mobile ad hoc networks.
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Ghani, Nasir. "Available bit rate services in ATM networks." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/nq22206.pdf.
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Thomas, Scott D. "Vector processor services for local area networks." Thesis, This resource online, 1991. http://scholar.lib.vt.edu/theses/available/etd-10312009-020126/.
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Lee, Narm Hee. "Routing in high speed integrated services networks." Thesis, University of Cambridge, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.387455.
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Gibson, Rachel. "Pollination networks and services in agro-ecosystems." Thesis, University of Bristol, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.601158.
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Pollinators provide essential services to crop and wild plants. Declines of native and managed pollinators have prompted considerable interest in the identity and importance of native pollinators and the services they provide. In agro-ecosystems there is particular concern over the impact of landscape simplification on these communities of 'service providers' , This thesis has two main aims; First, to investigate the ecosystem service of crop pollination by native insects, using ecological networks as a tool to identify pollinator interactions with crops, natural and semi-natural habitats. Pollination services to Fragaria x ananassa (strawberry), an insect-pollinated, high value crop, were used as a model system for this work. Networks were used to study interactions and spillover of insects between crop and semi-natural habitats at the local scale, the potential effects of poll in at or extinctions on pollination services, as well as pollen-transport interactions at the field scale and how they are affected by the structure of the surrounding landscape. The second aim of the thesis is {o explore the effects of sampling bias, specifically the type of sampling methodology employed, on the structure of the resulting plant-pollinator networks. The work presented in this thesis demonstrates the wide range of possible applications of plantpollinator networks to the study of crop pollination. The results reveal temporal changes in pollinator importance, spillover of pollinators across boundaries between crop and seminatural habitats and negative effects of landscape structure on pollinator communities and their interactions along with significant impacts of sampling bias on network structure. Network approaches to conservation issues reveal hidden effects of anthropogenic change on biodiversiry and are likely to be increasingly employed for such purposes in the future. The thesis ends by highlighting areas for improvement in the application of plant pollinator networks to the study of plant-pollinator community structure and pollination services, in order that ecologists gain the maximum benefit from using networks to answer questions about the effects of human activity on plant-pollinator communities and interactions.
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Magistretti, Eugenio <1978>. "Dynamic services in mobile ad hoc networks." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2007. http://amsdottorato.unibo.it/399/.
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The increasing diffusion of wireless-enabled portable devices is pushing toward the design of novel service scenarios, promoting temporary and opportunistic interactions in infrastructure-less environments. Mobile Ad Hoc Networks (MANET) are the general model of these higly dynamic networks that can be specialized, depending on application cases, in more specific and refined models such as Vehicular Ad Hoc Networks and Wireless Sensor Networks. Two interesting deployment cases are of increasing relevance: resource diffusion among users equipped with portable devices, such as laptops, smart phones or PDAs in crowded areas (termed dense MANET) and dissemination/indexing of monitoring information collected in Vehicular Sensor Networks. The extreme dynamicity of these scenarios calls for novel distributed protocols and services facilitating application development. To this aim we have designed middleware solutions supporting these
challenging tasks. REDMAN manages, retrieves, and disseminates replicas of software resources in dense MANET; it implements novel lightweight protocols to maintain a desired replication degree despite participants mobility, and efficiently perform resource retrieval. REDMAN exploits the high-density assumption to achieve scalability and limited network overhead. Sensed data gathering and distributed indexing in Vehicular Networks raise similar
issues: we propose a specific middleware support, called MobEyes, exploiting node mobility to opportunistically diffuse data summaries among neighbor vehicles. MobEyes
creates a low-cost opportunistic distributed index to query the distributed storage and to determine the location of needed information. Extensive validation and testing of REDMAN and MobEyes prove the effectiveness of our original solutions in limiting communication overhead while maintaining the required accuracy of replication degree and indexing completeness, and demonstrates the feasibility of the middleware approach.
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Siddiqui, Mahboob-ul-Haq. "Performance measurement methodology for integrated services networks." Thesis, Loughborough University, 1989. https://dspace.lboro.ac.uk/2134/15430.
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With the emergence of advanced integrated services networks, the need for effective performance analysis techniques has become extremely important. Further advancements in these networks can only be possible if the practical performance issues of the existing networks are clearly understood. This thesis is concerned with the design and development of a measurement system which has been implemented on a large experimental network. The measurement system is based on dedicated traffic generators which have been designed and implemented on the Project Unison network. The Unison project is a multisite networking experiment for conducting research into the interconnection and interworking of local area network based multi-media application systems. The traffic generators were first developed for the Cambridge Ring based Unison network. Once their usefulness and effectiveness was proven, high performance traffic generators using transputer technology were built for the Cambridge Fast Ring based Unison network. The measurement system is capable of measuring the conventional performance parameters such as throughput and packet delay, and is able to characterise the operational performance of network bridging components under various loading conditions. In particular, the measurement system has been used in a 'measure and tune' fashion in order to improve the performance of a complex bridging device. Accurate measurement of packet delay in wide area networks is a recognised problem. The problem is associated with the synchronisation of the clocks between the distant machines. A chronological timestamping technique has been introduced in which the clocks are synchronised using a broadcast synchronisation technique. Rugby time clock receivers have been interfaced to each generator for the purpose of synchronisation. In order to design network applications, an accurate knowledge of the expected network performance under different loading conditions is essential. Using the measurement system, this has been achieved by examining the network characteristics at the network/user interface. Also, the generators are capable of emulating a variety of application traffic which can be injected into the network along with the traffic from real applications, thus enabling user oriented performance parameters to be evaluated in a mixed traffic environment. A number of performance measurement experiments have been conducted using the measurement system. Experimental results obtained from the Unison network serve to emphasise the power and effectiveness of the measurement methodology.
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Huck, Paul E. (Paul Eriksen) 1978. "Zero configuration name services for IP networks." Thesis, Massachusetts Institute of Technology, 2001. http://hdl.handle.net/1721.1/86716.
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Thesis (M.Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2001.Includes bibliographical references (leaves 75-78).
by Paul E. Huck, Jr.
M.Eng.
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Solyman, Ahmed Amin Ahmed. "Multimedia services over wireless networks using OFDM." Thesis, University of Strathclyde, 2013. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=22548.
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This Thesis presents Multimedia systems based on Orthogonal Frequency Division Multiplexing (OFDM) multi carrier modulation system (MCM) architecture and signal processing techniques including discrete fractional Fourier transform (DFrFT), discrete fractional Cosine transform (DFrCT), and equalisation algorithms to mitigate the doubly dispersive channel effect on the OFDM communication systems. Equalisation algorithms are implemented for both the OFDM and the DFrFT orthogonal chirp division multiplexing (OCDM) systems. Mathematical formulae for the equalisation problem in doubly dispersive channel scenario are derived. A multimode system using both the OFDM and the DFrFT-OCDM depending on the communication channel characteristics and the system performance are presented. New low complexity equalisers based on the LSMR iterative algorithm are developed. The performance of these new equalisers is shown to be comparable to conventional low complexity equalisers however they require less complexity. A good improvement in the MCM systems under doubly dispersive channels is gained using the DFrCT transformation as bases for the MCM system with the new low complexity equalisers. Finally, extension to the previous work in multi input multi output (MIMO) is proposed including multi input single output (MISO) Alamouti space time block codes (STBCs), the extended orthogonal STBC (EO-STBC) MISO systems and the MIMO systems with the using of equalisation to improve the overall system performance under doubly dispersive fading channels.
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Silva, Jesús, Naveda Alexa Senior, Movilla José Solórzano, Núẽz William Niebles, and Palma Hugo Hernández. "Neural Networks for the Web Services Classification." Institute of Physics Publishing, 2020. http://hdl.handle.net/10757/652143.
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This article introduces a n-gram-based approach to automatic classification of Web services using a multilayer perceptron-type artificial neural network. Web services contain information that is useful for achieving a classification based on its functionality. The approach relies on word n-grams extracted from the web service description to determine its membership in a category. The experimentation carried out shows promising results, achieving a classification with a measure F=0.995 using unigrams (2-grams) of words (characteristics composed of a lexical unit) and a TF-IDF weight.
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Mukanyiligira, Didacienne. "Virtualization of multicast services in WiMAX networks." Doctoral thesis, University of Cape Town, 2017. http://hdl.handle.net/11427/27360.
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Multicast service is one of the methods used to efficiently manage bandwidth when sending multimedia content. To improve bandwidth utilisation, virtualization is often invoked because of its additional features such as bandwidth sharing and support of services that require high volumes of transactional data. Currently, network providers are concerned with the bandwidth amount for efficient use of the limited wireless network capabilities and the provision of a better quality of service. The virtualization design of a multicast service framework should satisfy several objectives. For example, it should enable the interchange of service delivery between multiple networks with one shareable network infrastructure. Also, it should ensure efficient use of network resources and guarantee users' demands of Quality of Service (QoS). Thus, the design of virtualization of multicast service framework is a complex research study. Due to the bandwidth-related arguments, a strong focus has been put on technical issues that facilitate virtualization in wireless networks. A well-designed virtualized network guarantees users with the required quality service. Similarly, virtualization of multicast service is invoked to improve efficient utilisation of bandwidth in wireless networks. As wireless links prove to be unstable, packet loss is unavoidable when multicast service-oriented virtual artefacts are incorporated in wireless networks. In this thesis, a virtualized multicast framework was modelled by using Generalized Assignment Problem (GAP) methodology. Mixed Integer Linear Programing (MILP) was implemented in MATLAB to solve the GAP model. This was to optimise the allocation of multicast traffic to the appropriate virtual networks. Thus, the developed model allows users to have interchangeable services offered by multiple networks. Furthermore, Network Simulator version 3 (NS-3) was used to evaluate the performance of the virtualized multicast framework. Three applications, namely, voice over IP (VoIP), video streaming, and file download have been used to evaluate the performance of a multicast service virtualization framework in Worldwide Interoperability for Microwave Access (WiMAX) networks using NS-3. The performance evaluation was based on whether MILP is used or not used. The results of experimentation have revealed that there is good performance of virtual networks when multicast traffic is sent over one single virtual network instead of sending it over multiple virtual networks. Similarly, the results show that the bandwidth is efficiently used because the multicast traffic is not delivered through multiple virtual networks. Overall, the concepts, the investigations and the model presented in this thesis can enable mobile network providers to achieve efficient use of bandwidth and provide the necessary means to support services for QoS differentiations and guarantees. Also, the multicast service virtualization framework provides an excellent tool that can enable network providers to interchange services. The developed model can serve as a basis for further extension. Specifically, the extension of the model can boost load balancing in the flow allocation problem and activate a virtual network to deliver traffic. This may rely on the QoS policy between network providers. Therefore, the model should consider the number of users in order to guarantee improved QoS.
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Sussman, Jeremy Brand. "Group communication services versus wide-area networks /." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 1999. http://wwwlib.umi.com/cr/ucsd/fullcit?p9945774.
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Chebrolu, Kameswari. "Multi-access services in heterogeneous wireless networks /." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2004. http://wwwlib.umi.com/cr/ucsd/fullcit?p3127621.
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Naidoo, Vaughn. "Policy Based Network management of legacy network elements in next generation networks for Voice Services." Thesis, University of the Western Cape, 2002. http://etd.uwc.ac.za/index.php?module=etd&action=viewtitle&id=gen8Srv25Nme4_5830_1370595582.
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Simpson, Antony Paul. "An information services framework for commercial extension services." Thesis, Nelson Mandela Metropolitan University, 2014. http://hdl.handle.net/10948/8575.
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The first of the eight United Nations Millennium Development Goals for 2015 is to “Eradicate Extreme Poverty and Hunger”. Achieving this goal would be aided by having an effective and productive agricultural community. Agricultural organisations assist producers to be more effective in their operation through Commercial Extension Services (CES). Through CES, producers are advised and educated about new agricultural practices, techniques and products. A key component of CES is the provision of relevant information to producers. The problem this research addressed was that producers experience difficulty in accessing the information they require in a timeous, relevant and personalised manner. No suitable framework was found for agricultural organisations to use when designing and implementing an Information Services Platform. The main research objective was to develop and evaluate an Information Services Framework (ISF) for organisations offering information as a CES. The research methodology used to achieve this objective was Design Science Research (DSR). DSR is an iterative methodology with three cycles, namely the relevance, the design and the rigor cycles. The relevance cycle was used to acquire the information required to inform the design cycle. The information was collected by using literature research and empirical studies. The first study, the Producer Information Requirements Survey (PIRS) sought to determine the information requirements of grain producers and was conducted by interviewing grain producers in the Swartland region of South Africa. The second study, the Internet and Mobile Device Usage Survey (IMDUS) investigated the use of the Internet and mobile devices amongst South African producers by means of a national on-line survey. The quantitative and qualitative results of the analysis were used during the design phase to develop the ISF. The design phase of DSR process led to the creation of an ISF for providing Information as a Service (IaaS) in CES. The framework allows for information services to be provided in a manner and form customised to an individual producer’s preferences. The foundation of the framework is that information can be sourced from various sources, internal or external to the organisation and distributed to producers by using a unified platform. During the research, an agricultural organisation, BKB GrainCo used the proposed ISF to develop an Information Services Platform (ISP) to provide information to its producers. BKB GrainCo’s development process included two evaluations. The first evaluation, the Information Preferences Prototype Survey, was intended to test a key component of the framework, the nformation Preferences Profile. The Information Preferences Profile was conceptualized following the PIRS. In the PIRS it was determined that individual producers would prefer to specify what information they would receive, when they required it and have it delivered by using a medium of their choice. The second evaluation of the design phase was a Usability Study. The Usability Study was intended to test the functionality of the system across various technologies. The rigor cycle, following the implementation of BKB GrainCo’s ISP, contained the main evaluation, the Information Services Platform Evaluation. The evaluation was used to test the impact of BKB GrainCo’s ISP on perception of received service. The evaluation used a standardised version of the standardised SERVQUAL instrument specifically adapted in this research to measure the provision of IaaS. The results obtained during the evaluation indicated that the BKB GrainCo’s Information Services Platform was found to be valued by producers and improved the communication services of agricultural organisations. It was inferred from the successful implementation of BKB GrainCo’s ISP and the positive response from producers, after the evaluations, that the developed ISF was suitable for an agricultural organisation to provide CES. The theoretical contributions included underpinning the concept of CES in terms of stakeholder theory. Its underpinning provides justification for agricultural organisations to improve CES – including the provision of information. A second theoretical contribution was the extension of SERVQUAL as an IS theory by developing and validating a dimension designed to test the provision of IaaS. Providing producers with accurate and reliable personalised information has the capacity to improve producers’ ability to make informed decisions. Informed decision making will contribute to having an effective and productive agricultural community; resulting in improvement of agricultural output and contributing to food security and job creation. Improved agricultural output, better food security and job creation are aspects which will contribute toward the attainment of the first of eight United Nations Millennium Development Goals for 2015, which is to “Eradicate Extreme Poverty and Hunger”.
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Jirón, Cecilia Sabina. "DISTRIBUTED SERVICES ON A LOCALNET 20 NETWORK." Thesis, The University of Arizona, 1985. http://hdl.handle.net/10150/275451.
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Cavalcanti, de Castro Marcel. "Enabling Multimedia Services over Wireless Multi-Hop Networks." Licentiate thesis, Karlstad University, Faculty of Economic Sciences, Communication and IT, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-3980.
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With the constant development of wireless technologies, the usageof wireless devices tends to increase even more in the future.Wireless multi-hop networks (WMNs) have emerged as a keytechnology to numerous potential scenarios, ranging from disasterrecovery to wireless broadband internet access. The distributedarchitecture of WMNs enables nodes to cooperatively relay othernode's packets. Because of their advantages over other wirelessnetworks, WMNs are undergoing rapid progress and inspiringnumerous applications. However, many technical issues still existin this field. In this thesis we investigate how Voice over IP(VoIP) and peer-to-peer (P2P) application are influenced bywireless multi-hop network characteristics and how to optimizethem in order to provide scalable communication.We first consider the deployment of VoIP service in wirelessmulti-hop networks, by using the Session Initiation Protocol (SIP)architecture. Our investigation shows that the centralized SIParchitecture imposes several challenges when deployed in thedecentralized wireless multi-hop environment. We find that VoIPquality metrics are severely degraded as the traffic and number ofmultiple hops to the gateway increase. In the context ofscalability, we further propose four alternative approaches whichavoid current limitations.In the second part of this thesis we tackle the network capacityproblem while providing scalable VoIP service over wirelessmulti-hop networks. The performance evaluation shows the influenceof intra and inter-flow interference in channel utilization, whichdirect impacts the VoIP capacity. In order to avoid the small VoIPpacket overhead, we propose a new adaptive hop-by-hop packetaggregation scheme based on wireless link characteristics. Ourperformance evaluation shows that the proposed scheme can increasethe VoIP capacity by a two-fold gain.The study of peer-to-peer applicability over wireless multi-hopnetworks is another important contribution. A resource lookupapplication is realized through structured P2P overlay. We showthat due to several reasons, such as characteristics of wirelesslinks, multi-hop forwarding operation, and structured P2Pmanagement traffic aggressiveness the performance of traditionalP2P applications is rather low in wireless multi-hop environments.Therefore, we suggested that a trade-off between the P2P lookupefficiency and the P2P management traffic overhead can be achievedwhile maintaining the overlay network consistency in wirelessmulti-hop networks.
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Shrinivas, V. Prasanna. "Pricing Multicast Network Services." Thesis, Indian Institute of Science, 2001. http://hdl.handle.net/2005/270.
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Multicast has long been considered an attractive service for the Internet for the provision of multiparty applications. For over a decade now multicast has been a proposed IETF standard. Though there is a strong industry push towards deploying multicast, there has been little multicast deployment by commercial Internet Service Providers (ISPs) and more importantly most end-users still lack multicast capabilities. Depending on the underlying network infrastructure, the ISP has several options of implementing his multicast capabilities. With significantly faster and more sophisticated protocols being designed and prototyped, it is expected that a whole new gamut of applications that are delay sensitive will come into being. However, the incentives to resolve the conflicting interests of the ISPs and the end-users have to be provided for successful implementation of these protocols. Thus we arrive at the following economic questions: What is the strategy that will enable the ISP recover his costs ? How can the end-user be made aware of the cost of his actions ? Naturally, the strategies of the ISP and the end-user depend on each other and form an economic game. The research problems addressed in this thesis are:
A pricing model that is independent of the underlying transmission protocols is prefered. We have proposed such a pricing scheme for multicast independent of the underlying protocols, by introducing the concept of pricing points* These pricing points provide a range of prices that the users can expect during a particular time period and tune their usage accordingly. Our pricing scheme makes both the sender and receiver accountable. Our scheme also provides for catering to heterogeneous users and gives incentive for differential pricing.
We explore a number of formulations of resource allocation problems arising in communication networks as optimization models. Optimization-based methods were only employed for unicast congestion control. We have extended this method for single rate multicast. We have also devised an optimization-based approach for multicast congestion control that finds an allocation rate to maximize the social welfare. Finally we also show that the session-splitting problem can also be cast as an optimization problem.
The commonly used "max-min" fairness criteria suffers from serious limitations like discriminating sessions that traverse large number of links and poor network utilization. We provide an allocation scheme that reduces discrimination towards multicast sessions that traverse many links and also improves network utilization.
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Reñé, Vicente Sergi. "Handoff management for infotainment services over vehicular networks." Doctoral thesis, Universitat Politècnica de Catalunya, 2015. http://hdl.handle.net/10803/317957.
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Intelligent Transportation Systems (ITS) has impulsed the vehicular communications at the present time. The vehicular communications field is a hot research topic and is attracting a great interest in the automotive industry and telecommunications. There are essentially two main lines of work: (1) communication services related to road safety and traffic information; and (2) information and entertainment services, also named infotainment services. These latter services include both transmitting multimedia (voice over IP, streaming, on-line gaming, etc.) and classic data services (e-mail, access to private networks, web browsing, file sharing, etc.). In this thesis we will focus on these infotainment services because further research in this immature research field is necessary and, until nowadays, the main effort of the research community regarding vehicular communication has been focused on road safety and traffic information.
Vehicular nodes need to be reached from the Internet and vice versa to be able to access to infotainment services. While vehicles move along the road infrastructure, they change their wireless point of attachment to the network. During this process, connectivity breaks down until the vehicle is connected again to a new road side unit in its area. This disconnection causes a disruption in the communications. Fast handoffs are a crucial requirement for vehicular networks to avoid long disruption times, since the high speed of vehicular nodes involves suffering a lot of handoffs during an Internet connection.
This thesis is focused on Vehicular-to-Infrastructure (V2I) real-time infotainment services. The main contributions of this thesis are: i) a new testing framework for V2I communications to be able to test infotainment services in an easy way; ii) the analysis of the deployability of infotainment video services in vehicular networks using mobility protocols; and iii) the development of a new TCP architecture that will provide a better performance for all TCP-based infotainment services in a vehicular scenario with handoffs.
In this thesis, firstly, we propose a new testing framework for vehicular infotainment applications. This framework is a vehicular emulation platform that allows testing real applications installed on Linux virtual machines. Using emulation, we are able to evaluate the performance of real applications with real-time requirements, so we can test multimedia applications used to offer infotainment services in vehicular scenarios in a straightforward way.
Secondly, using the testing framework implemented in the first part of the thesis, we have done a performance evaluation of an infotainment service. Among these services, we think that video on demand services on highways will be interesting for users, and generate revenue to network operators. So we evaluated how network-layer handoffs can limit the deployment of a video streaming service. According to the results obtained, driving at high speeds will be an issue for a correct playback of video content, even using fast handoffs techniques.
Finally, we developed a new TCP architecture to enhance performance during handoffs. Most of the non-safety services on ITS rely on the Transport Control Protocol (TCP), one of the core protocols of the Internet Protocol Suite. However there exists several issues related to TCP and mobility that can affect to TCP performance, and these issues are particularly important in vehicular networks due to its high mobility. Using new IEEE 802.21 MIH services, we propose a new TCP architecture that is able to anticipate handoffs, permitting to resume the communication after a handoff, avoiding long delays caused by TCP issues and adapting the TCP parameters to the new characteristics of the network. Using the architecture proposed, the performance of TCP is enhanced, getting a higher overall throughput and avoiding TCP fairness issues between users.Els Sistemes de Transport Intel·ligents (ITS) han impulsat les comunicacions vehiculars en l'actualitat. Les comunicacions vehiculars és un camp d'investigació de moda, i està atraient un gran interès en la indústria automobilística i de les telecomunicacions. En el camp de les comunicacions vehiculars, hi ha principalment dues línies de treball: (1) serveis de comunicacions relacionats amb la seguretat viària i la informació del trànsit; i (2) serveis d'informació i entreteniment, també anomenats serveis d'infotainment. Aquests últims inclouen tant serveis multimèdia (veu sobre IP, streaming, jocs on-line, etc.), com serveis clàssics de dades (correu electrònic, accés a xarxes privades, navegació web, compartir arxius, etc.). En aquesta tesi ens centrarem en aquests serveis d'infotainment ja que és necessari aprofundir en la investigació per aquests tipus de serveis, ja que, fins avui, els esforços de la comunitat científica en el camp de les comunicacions vehiculars s'ha centrat en els serveis relacionats amb la seguretat viària i la informació del trànsit. Els nodes vehiculars necessiten tenir connexió a Internet per a poder tenir accés als serveis d'infotainment. Mentre els vehicles estan en moviment a través de la xarxa viària, els vehicles han d'anar canviant el punt de connexió sense fils amb la xarxa. Durant aquest procés de canvi de punt de connexió, anomenat handoff, es perd la connectivitat fins que el vehicle es reconnecta a un altre punt de connexió viària prop de la seva àrea. Aquesta desconnexió causa interrupcions en les comunicacions. Uns handoffs ràpids són bàsics a les xarxes vehiculars per a evitar llargs períodes d'interrupció durant les comunicacions, ja que la gran velocitat a la que es mouen els nodes vehiculars significa un gran nombre de handoffs durant una connexió a Internet. Aquesta tesi es centra en serveis d'infotaiment en temps real per a comunicacions Vehicle-a-Infraestructura (V2I). Les principals contribucions d'aquesta tesi son: i) un nou marc de proves per a les comunicacions (V2I) per a poder provar serveis d'infotainment d'una manera fàcil; ii) l'anàlisi de la viabilitat del desplegament de serveis d'infotainment de vídeo en xarxes vehiculars utilitzant protocols de mobilitat IP; i iii) el desenvolupament d'una nova arquitectura TCP que proporciona un millor funcionament per a tots aquells serveis d'infotainment basats en el protocol TCP en un escenari vehicular amb handoffs. En aquesta tesi, primer proposem un nou marc de proves per a aplicacions vehiculars d'infotainment. Aquest marc és una plataforma d'emulació vehicular que permet provar aplicacions reals instal·lades en màquines virtuals Linux. Utilitzant l'emulació, som capaços d'avaluar el rendiment d'aplicacions reals amb característiques de temps real. D'aquesta manera es poden avaluar aplicacions multimèdia utilitzades per oferir serveis d'infotainment d'una forma senzilla en escenaris vehiculars. Segon, utilitzant el marc de prova implementat en la primera part de la tesi, hem avaluat el rendiment d'un servei d'infotainment. Entre aquest tipus de servei, creem que els serveis de vídeo sota demanda en autopistes/autovies serà interessant pels usuaris i generarà beneficis per als operadors de la xarxa. Per tant, hem avaluat com els handoffs a nivell de la capa de xarxa poden limitar el desplegament d'un servei de streaming de vídeo sota demanda. D'acord amb els resultats obtinguts, conduir a grans velocitats podria ser un problema per a poder reproduir un vídeo correctament, tot i utilitzar tècniques de handoffs ràpids. Finalment, hem desenvolupat una nova arquitectura TCP per a millorar el rendiment del protocol durant els handoffs. La majoria dels serveis d'infotainment utilitzen el Protocol de Control de Transport (TCP), un dels principals protocols de la pila de protocols d'Internet. Però existeixen forces problemes relacionats amb l'ús de TCP i la mobilitat que n'afecta el rendiment, i aquests problemes són particulars
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Farkas, Károly. "Supporting distributed services in Mobile Ad hoc Networks /." Aachen : Shaker Verlag, 2007. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=16987.
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Wang, Ning. "Scalable multicast provisioning in IP differentiated services networks." Thesis, University of Surrey, 2004. http://epubs.surrey.ac.uk/843389/.
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The emergence of point-to-multipoint applications with Quality of Service (QoS) requirements in the Internet has prompted research towards the deployment of multicast communications in Differentiated Services (DiffServ) environments. However, despite many past research efforts, global availability of IP multicast is still a pie in the sky for Internet users, let alone applications with QoS guarantees. One of the key factors that hamper associated progress is scalability, in terms of various types of states associated with routing and signaling in both multicast and QoS. In this thesis we aim at a scalable architectural design of multicast service provisioning for end users with heterogeneous QoS requirements, targeted to the DiffServ environment. Our architecture consists of three planes: management, control and data plane. First of all, we design and evaluate the Offline Multicast Traffic Engineering (OMTE) building block in the management plane for QoS aware multicast service dimensioning. The main novelty of this scheme is that we shift away from the commonly used Multi-Protocol Label Switching (MPLS) based traffic engineering, and address the bandwidth constrained IP multicast TE directly based on link state routing protocols. With this approach, end-to-end performance can be achieved without MPLS explicit routing that potentially suffers from scalability problems in terms of Label Switching Path (LSP) maintenance and is relatively expensive to deploy. In the control plane, we propose two different paradigms. QoS aware Source Specific Multicast (QSSM) is designed for dedicated multicast delivery tree construction in different QoS classes, while another overlay scheme, known as Differentiated QoS Multicast (DQM), attempts to build a single hybrid tree that exhibits heterogeneous QoS channels within the network. In both approaches, multicast group addresses are used to encode QoS class information, and the associated benefit is reflected in scalability and backwards compatibility; neither underlying multicast protocols nor existing routers need any extension for carrying and maintaining QoS states within the network. Finally, envisaging the importance of protecting dimensioned resources from Denial-of-Service (DoS) attacks from malicious hosts, we propose the Multicast Sender Access Control (MSAC) mechanism, which is indispensable in multicast security, but still lacks significant attention from the research community. We focus on bi-directional multicast trees, which is the most vulnerable routing paradigm to DoS attacks. Both intra- and inter-domain control mechanisms are addressed with scalability considerations in mind.
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Dong, Ying. "Providing security services for mobile ad hoc networks." Click to view the E-thesis via HKUTO, 2007. http://sunzi.lib.hku.hk/HKUTO/record/B3955711X.
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Shi, Zheng. "Real-time communication services for networks on chip." Thesis, University of York, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.516403.
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Dong, Ying, and 董穎. "Providing security services for mobile ad hoc networks." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2007. http://hub.hku.hk/bib/B3955711X.
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Mahfooz, Saeed. "Mechanisms for differential services in the access networks." Thesis, Liverpool John Moores University, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.343197.
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Van, Wamelen Riaan Joop. "Artificial neural networks in the financial services industry." Thesis, Stellenbosch : Stellenbosch University, 1999. http://hdl.handle.net/10019.1/85178.
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Thesis (MBA)--Stellenbosch University, 1999.ENGLISH ABSTRACT: Neural networks are computer systems that attempt to mimic the operation of the human brain. In contrast to traditional systems these systems can learn and will change their behaviour over time. In the highly competitive business environment of today, neural networks is one of many technologies that can assist organisations in gaining a competitive advantage. Neural networks also find application in the financial services industry. Applications range from corporate distress or failure models to forecasting of stock prices and many others. Generally speaking, neural networks often offer an exciting alternative to traditional methods of forecasting and classification in this industry. Neural networks must be implemented with care and judgement, as their performance is sensitive with respect to their construction and architecture. Neural networks, as with other technologies, rarely operate in isolation. Neural networks can be integrated with expert systems, genetic algorithms, data mining and even traditional statistical and operational research techniques. Integration produces systems in which the whole is greater than the sum of the parts. Neural networks are also researched and applied in the South African financial services industry, both at an academic and commercial level. Indications are that South Africa is not far behind the international community in exploring the benefits of neural networks.
AFRIKAANSE OPSOMMING: Neurale netwerke is rekenaarstelsels wat poog om die werking van die menslike brein na te boots. In kontras met tradisionele stelsels, leer neurale netwerke en verander dus hul gedrag met verloop van tyd. In vandag se hoogs kompeterende besigheids omgewing, is neural netwerke een van vele tegnologieë wat organisasies kan gebruik om ‘n mededingende voordeel te bekom. Neurale netwerke het ook toepassing in die finansiële dienste industrie. Toepassings wissel van korporatiewe mislukkings modelle tot die vooruitskatting van aandele pryse en vele ander. Neurale netwerke bied ‘n opwindende alternatief tot tradisionele modelle vir vooruitskatting en klassifikasie. Toepassings van neurale netwerke moet egter met oorleg plaasvind, aangesien hul prestasie sterk afhanklik is van hul konstruksie en argitektuur. Soos met ander tegnologie, word neurale netwerke selde in isolasie geïmplementeer. Neurale netwerke kan met sukses geïntegreer word met ekspert stelsels, genetiese algoritmes, data ontginnings metodes sowel as tradisionele statistiese of operasionele navorsings metodes. Integrasie bied stelsels wat meer bied as die som van die onafhanklike komponente. Neurale netwerke word ook in die Suid-Afrikaanse finansiële industrie nagevors en toegepas. Alle indikasies dui daarop dat, met betrekking tot die navorsing van voordele van neurale netwerke, Suid Afrika nie ver agter die internasionale gemeenskap is nie.
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Guimarães, Carlos Eduardo Magalhães. "Discovery of media independent services for heterogeneous networks." Master's thesis, Universidade de Aveiro, 2011. http://hdl.handle.net/10773/8834.
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Mestrado em Engenharia de Computadores e TelemáticaA recente proliferação de nós móveis com múltiplas interfaces sem fios e a constituição de ambientes heterogéneos possibilitaram a criação de cenários complexos onde os operadores de rede necessitam de disponibilizar conectividade para diferentes tipos de redes de acesso. Assim, a norma IEEE 802.21 foi especificada de forma a facilitar e optimizar os procedimentos de handover entre diferentes tecnologias de acesso sem perda de conectividade. Para cumprir o seu propósito, a norma disponibiliza serviços chamados Media Independent Handover e que permitem o controlo e a obtenção de informação de diferentes ligações. A configuração estática destes serviços por parte do nó móvel torna-se ineficiente devido aos múltiplos cenários possíveis. Desta forma, o nó móvel deve descobrir nós da rede que providenciem serviços de mobilidade e as suas capacidade de uma forma dinâmica. Nesta dissertação, um conjunto de mecanismos para descoberta de serviços de handover independentes do acesso são analisados, implementados e avaliados em termos de duração e quantidade de informação trocada. Um novo mecanismo de descoberta de entidades locais é também proposto e avaliado, demonstrando que a sua utilização aumenta o desempenho e requer a troca de menos quantidade de informação.
The recent proliferation of mobile nodes with multiple wireless interfaces, in addition to the creation of heterogeneous environments, created complex scenarios where network operators need to provide connectivity for di erent kinds of access networks. Therefore, the IEEE 802.21 standard has been speci ed to facilitate and optimize handover procedures between di erent access technologies in a seamless way. To ful l its purpose, it provides Media Independent Handover services which allow the control and gathering of information from di erent links. The static con guration of these services by the MN becomes ine cient due to the amount of possible scenarios. Thus, the MN must discover the network-supporting nodes and their capabilities in a dynamic way. In this work, a series of proposed Media Independent Handover discovery procedures are analyzed, implemented and evaluated in terms of duration and amount of exchanged information. In addition, a novel discovery procedure for local entities is proposed and evaluated, showing that its deployment increases the performance and requires less information exchanged.
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Dong, Liqin Carleton University Dissertation Engineering Electrical. "Compressed voice in integrated services frame relay networks." Ottawa, 1992.
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Sharon, C. M. (Colin Michael) Carleton University Dissertation Engineering Systems and Computer. "Compressed video in integrated services frame relay networks." Ottawa, 1994.
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Sonalker, Anuja Anilkumar. "Designing robust collaborative services in distributed wireless networks." College Park, Md.: University of Maryland, 2007. http://hdl.handle.net/1903/7662.
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Thesis (Ph. D.) -- University of Maryland, College Park, 2007.Thesis research directed by: Dept. of Electrical and Computer Engineering. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.