Tesi sul tema "Mobile networks"
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1
Cheng, Jerry. "Collaborative network security for heterogeneous mobile networks". Diss., Restricted to subscribing institutions, 2007. http://proquest.umi.com/pqdweb?did=1472132471&sid=1&Fmt=2&clientId=1564&RQT=309&VName=PQD.
Testo completo
2
Glidden, Todd P. "Privacy for mobile networks via network virtualization". Thesis, Monterey, Calif. : Naval Postgraduate School, 2009. http://edocs.nps.edu/npspubs/scholarly/theses/2009/March/09Mar%5FGlidden.pdf.
Testo completoAbstract (sommario):
Thesis (M.S. in Computer Science)--Naval Postgraduate School, March 2009.Thesis Advisor(s): Singh, Gurminder ; Gibson, John. "March 2009." Description based on title screen as viewed on April 23, 2009. Author(s) subject terms: Privacy, mobile networks, first responders, mobile file sharing, data dissemination. Includes bibliographical references (p. 47-49). Also available in print.
3
Suárez, Trujillo Luis Carlos. "Securing network slices in 5th generation mobile networks". Thesis, Brest, 2020. http://www.theses.fr/2020BRES0050.
Testo completoAbstract (sommario):
Le « network slicing » est la pierre angulaire pour la conception et le déploiement de services de communication à forte valeur ajoutée qui seront supportés par les nouveaux cas d’usage introduits par la nouvelle architecture 5G. Ce document souligne le défi que représente l’isolation des « network slices », et la gestion de sa sécurité en fonction des politiques retenues.Tout d’abord, un nouveau modèle de contrôle d’accès a été créé. Il permet de sécuriser les interactions entre les fonctions réseaux supportées par les systèmes 5G. Ensuite, la gestion des interactions entre les «network slices » a été abordée. On utilise le concept de chaînes de « network slices », qui seront mises en oeuvre après validation des contraintes de sécurité selon la politique choisie. Enfin, une méthode de quantification de l’isolation a été mise au point, permettant de connaître le degré d’isolation d’un service de communication offert via des « network slices». Cela permet aux opérateurs de réseau et aux clients de mesurer le degré d’isolation, puis d’améliorer la configuration des « network slices » afin de le renforcer. Ces éléments établissent un cadre solide contribuant à sécuriser, verticalement, les services de communication d’un réseau 5G et à évaluer le degré de sécurité en ce qui concerne leurs interactions et leur isolationNetwork slicing is a cornerstone in the conception and deployment of enriched communication services for the new use cases envisioned and supported by the new 5G architecture.This document makes emphasis on the challenge of the network slicing isolation and security management according to policy. First, a novel access control model was created, that secures the interactions between network functions that reside inside the 5G system. Then, the management of the interactions between network slices was addressed. We coin the concept of network slice chains, which are conceived after security constraint validation according to policy. Lastly, a method to quantify isolation was developed, permitting to find out how well isolated a communication service is, which is offered via network slices. This enables network operators and customers to measure the isolation level and improve the configuration of the network slices so the isolation level can be enhanced. These components establish a solid framework that contributes to secure, vertically, the communication services of a 5G network and assess how secure they are with respect to their interactions and isolation
4
Moessner, K. "Reconfigurable mobile communication networks". Thesis, University of Surrey, 2001. http://epubs.surrey.ac.uk/844245/.
Testo completoAbstract (sommario):
Telecommunication technologies and networks are constantly changing; with the introduction of the GSM system the shift from wired to wireless telephony experienced a unique boom. Since then, behaviour and communication needs of users (i.e. subscribers) have undergone rapid changes from initially the need for pure wireless voice transmission to now data and multimedia content traffic. Introduction of the 3rd Generation (UMTS/IMT 2000) promised the delivery of these services and the integration with the Internet. However, legacy technologies and networks are not likely to be replaced soon, the different wireless and wired communication and information infrastructures will co-exist and will have to work, seemingly seamless, together. The here documented research work delivers basic mechanisms supporting this integration, therefore a variety of technologies from different areas, ranging from Software Radio technology to Object-Oriented computing, have been brought together to introduce reconfigurability to mobile communication networks. Distributed object computing technologies are evaluated and their application as signalling and support platforms for reconfigureable systems is shown in different examples. Other novelties are the introduction of a protocol for download of reconfiguration software, from various software sources, these sources include Smart Cards, wired outlets and Over-The-Air. Furthermore, an object-oriented framework for flexible, 'on-the-fly' protocol exchange has been developed; the mechanisms and architecture of this framework are described within this thesis. Combining protocol reconfiguration, software download and distributed platforms and focusing on control and management of reconfiguration have led to the design and definition of a reconfiguration management architecture. Functionality and structure of this architecture are documented, and its single modules are described. Providing means and mechanisms enabling management and control of reconfiguration within reconfigureable mobile communication networks is the purpose of this thesis. KM, Guildford, July 2001 Key words: reconfiguration, reconfiguration management. Software Radio, object-orientation, middleware, CORBA, Universal Control CHannel.
5
Dengiz, Orhan Smith Alice E. "Maximizing connectivity and performance in mobile ad hoc networks using mobile agents". Auburn, Ala., 2007. http://repo.lib.auburn.edu/2007%20Fall%20Dissertations/Dengiz_Orhan_22.pdf.
Testo completo
6
Cullen, Cionaith. "Network and signalling aspects of satellite personal communication networks". Thesis, University of Surrey, 1995. http://epubs.surrey.ac.uk/842984/.
Testo completoAbstract (sommario):
The use of satellites for mobile communication applications has become a global issue. The use of handheld, vehicle mounted and transportable terminals is a key feature of Satellite Personal Communication Networks (S-PCNs). Due to the higher eirp requirements on the Earths surface and also because of their inherent delay, geostationary (GEO) satellites are not considered suitable for such applications. Instead, constellations of satellites at lower altitudes have been proposed for use in what are termed 2nd generation mobile satellite communication systems. Low intensity regions in the Earths surrounding trapped radiation bands, have resulted in two altitude bands of specific interest, resulting in two constellation types - LEO (Low Earth Orbit) constellations at around 1,000 km and MEO (Medium Earth Orbit) constellations at around 10,000 km. A satellite constellation consists of a number of satellites orbiting at the same altitude and inclination and phased in a specific way. The work reported in this thesis proposes a network control architecture for LEO or MEO based S-PCN systems. Air-interface signalling aspects are then considered for mobility management and call setup signalling. LEO and MEO constellation design aspects and properties are initially considered. Important implications on the control network are drawn based on constellation coverage and connectivity properties. Other system constraints such as terrestrial network interworking considerations as well as user, network operator and regulator requirements are also considered. Finally network and more specifically satellite control signalling is examined before a S-PCN architecture is proposed. The reference architecture results in constellation control being distributed globally with individual satellite control, at any one time, being located at a specific earth station. The use of two earth station types allows network administration to be separated from traffic channel carrying aspects. In order to reduce system setup cost and delay, the reuse of network related standards from the GSM terrestrial mobile communication system is envisaged. An equivalence is made between the S-PCN architecture and the GSMs terrestrial architecture. Network implementation aspects are considered for a 14 satellite MEO constellation. Network implications resulting from the use of LEO and MEO constellations are considered. After an examination of S-PCN traffic demand on a MEO constellation, mobility management signalling is considered. A new approach is proposed based on the use of a positioning system. The performance of this approach is examined from a system signalling viewpoint for both LEO and MEO constellations and a method to minimise the required amount of signalling is described. The air interface signalling procedure for location update, based on a modified GSM network layer protocol, is simulated from a delay point of view for both LEO and MEO constellations. User-originated, user-terminated and user-to-user call setup signalling were also simulated and their delay performance examined. The importance of random access channel delay and of user cooperation with the link were highlighted as aspects which have a significant influence on the average signalling delay. Finally, the effect of common and dedicated control channel system signalling on satellite power consumption, based on busy hour call setup and mobility management signalling estimates, was examined for a MEO constellation. From this, conclusions can be made on the signalling power efficiency of S-PCN systems.
7
Trullols, Cruces Oscar. "Information dissemination in mobile networks". Doctoral thesis, Universitat Politècnica de Catalunya, 2014. http://hdl.handle.net/10803/276176.
Testo completoAbstract (sommario):
This thesis proposes some solutions to relieve, using Wi-Fi wireless networks, the data consumption of cellular networks using cooperation between nodes, studies how to make a good deployment of access points to optimize the dissemination of contents, analyzes some mechanisms to reduce the nodes' power consumption during data dissemination in opportunistic networks, as well as explores some of the risks that arise in these networks.
Among the applications that are being discussed for data off-loading from cellular networks, we can find Information Dissemination in Mobile Networks.
In particular, for this thesis, the Mobile Networks will consist of Vehicular Ad-hoc Networks and Pedestrian Ad-Hoc Networks. In both scenarios we will find applications with the purpose of vehicle-to-vehicle or pedestrian-to-pedestrian Information
dissemination, as well as vehicle-to-infrastructure or pedestrian-to-infrastructure Information dissemination. We will see how both
scenarios (vehicular and pedestrian) share many characteristics, while on the other hand some differences make them unique, and therefore requiring of specific solutions. For example, large car batteries relegate power saving techniques to a second place, while power-saving techniques and its effects to network performance is a really relevant issue in Pedestrian networks.
While Cellular Networks offer geographically full-coverage, in opportunistic Wi-Fi wireless solutions the short-range non-fullcoverage paradigm as well as the high mobility of the nodes requires different network abstractions like opportunistic networking,
Disruptive/Delay Tolerant Networks (DTN) and Network Coding to analyze them.
And as a particular application of Dissemination in Mobile Networks, we will study the malware spread in Mobile Networks.
Even though it relies on similar spreading mechanisms, we will see how it entails a different perspective on Dissemination.
8
Zincir, Ibrahim. "Behavioural profiling in mobile networks". Thesis, University of Plymouth, 2011. http://hdl.handle.net/10026.1/884.
Testo completoAbstract (sommario):
In the last 20 years mobile devices gained an important role in daily life and became must have items for everyone. As mobile devices give us the much needed flexibility and mobility, they also represent one major concern; security. As the information is transmitted from node to node via radio frequencies, an imposter can gain access into a mobile network without the need to gain physical access to firewalls and gateways. Also, as they are light and small, mobile devices are easily lost and often used without any PIN or password protection enabled. Hence, it is not difficult for someone even without any technical knowledge to gain access to such devices if they have been left behind or stolen. As traditional intrusion detection systems are not very effective against this kind of attack, there is a need of a different approach that can assist in the identification of a potential imposter. This thesis begins by assessing the security needs of the mobile devices, and establishes the perceived inadequacy of existing safeguards in this respect. Therefore this research considers using Behaviour-Based Mobile Intrusion Detection System (BeMIDS) that aims to assist the identification of anomalous user activity. This in return presents the two main characteristics needed to classify a legitimate user inside a mobile network: first with whom, when and what type of connection is established and then at where the mobile device is left open. After this the research proposes a novel approach that investigates the application of three machine learning algorithms to profile user behaviour in mobile networks. In BeMIDS, historical user profiles are created and then compared with the real-time ones in order to detect unusual activity in mobile networks. If a user’s behaviour changes, this results in alerting the system as an anomalous activity. Specific examples of behaviours that BeMIDS appears to be particularly sensitive to include duration (of calls and of connection with cell towers), time of day (calls are made and cell towers are connected), and frequency of caller usage. In order to classify a legitimate user over a mobile network the thesis then validates this approach by implementing C4.5, RIPPER and SOM algorithms over MIT’s Reality Mining Dataset. The results support the proposed architecture and present accuracy rate as high as 96% for call logs and 94% for tower logs under training conditions.
9
Huang, E. "Rethinking mobile ad hoc networks". Thesis, University of Cambridge, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.604708.
Testo completoAbstract (sommario):
This thesis explores the physical layer feasibility, performance and limitations of MANETs through simulation and evaluation of a novel application scenario. The results of the work are intended to help researchers understand how and where MANETs can be used in the future, as well as to better understand physical layer considerations and methods of improving the physical layer performance of large scale, highly mobile MANETs. The thesis also investigates the effect and feasibility of using fixed relay or dispatch points that act as intermediate relays or source/sinks for messages. The results show the relative benefits of using relays vs. dispatch points, as well as the differences owing to the position, configuration and number of fixed points. We are then able to deduce the optimum configuration and type of fixed nodes to use to achieve the best results under various circumstances. Given the limited unlicensed spectrum available and the potentially high number of nodes in a bounded area, it is likely that interference will become a significant limiting factor for performance. The thesis explores this and other related issues to discover the significance of their effects and the necessary bounds for reasonable performance. We also explore the use of various techniques to mitigate these effects. The thesis concludes by investigating the issue of cooperation incentives. Without sufficient nodes cooperating to provide relaying functions, a MANET cannot function properly. Consequently various proposals have been made which provide incentives for individual users of a MANET to cooperate with each other. We examine the drawbacks of currently proposed incentive systems and propose a new solution.
10
Assasa, Hany. "Service Mobility in Mobile Networks". Thesis, KTH, Skolan för informations- och kommunikationsteknik (ICT), 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-166540.
Testo completoAbstract (sommario):
In the current mobile network architecture, network traffic between user equipment (UE) and services deployed on the public cloud is tromboned towards the anchor point which could lead to network congestion. Deploying services closer to the UE, for example near the eNodeB, is a potential solution. The services are deployed on small scale data centers connected to, or collocated with the eNodeB, called ’eNodeB-Cloud’ (eNBC). Mobility of UEs presents a challenge for deploying services in an eNBC. When the UE is handed over from one eNodeB to another, seamless migration of UE context between the service instances running in different eNBCs needs to be ensured. In this thesis, we propose a Platform as a Service framework to enable UE context migration between eNBCs. The architecture consists of handover signaling mechanism, network session migration technology, context transfer protocol and a set of APIs towards the service. The evaluation of the prototype implementation shows that virtualization causes some extra delays to the UE context migration time. Whereas when virtualization is omitted, the time taken to migrate a UE context between two eNBCs is in the order of 12 ms on average, which is within the limit of handover interruption time between two LTE-eNodeBs.
11
Haghnegahdar, Alireza. "Interference in wireless mobile networks". Thesis, University of British Columbia, 2014. http://hdl.handle.net/2429/46713.
Testo completoAbstract (sommario):
Given a set of positions for wireless nodes, the interference minimization problem is to assign a transmission radius (i.e., a power level) to each node such that the resulting communication graph is connected, while minimizing the maximum (respectively, average) interference. We consider the model introduced by von Rickenbach et al. (2005), in which each wireless node is represented by a point in Euclidean space on which is centered a transmis- sion range represented by a ball, and edges in the corresponding graph are symmetric. The problem is NP-complete in two or more dimensions (Buchin 2008) and no polynomial-time approximation algorithm is known. We show how to solve the problem efficiently in settings typical for wireless ad hoc networks. We show that if node positions are represented by a set P of n points selected uniformly and independently at random over a d-dimensional region, then the topology given by the closure of the Euclidean minimum spanning tree of P has O(log n) maximum interference, O(1) average inter- ference with high probability and O(1) expected average interference. This work is the first to examine average interference in random settings. We extend the first bound to a general class of communication graphs over a broad set of probability distributions. We present a local algorithm that constructs a graph from this class; this is the first local algorithm to provide an upper bound on expected maximum interference. To verify our results, we perform an empirical evaluation using synthetic as well as real world node placements.
12
Gudapati, Supriya. "Securing mobile ad hoc networks". Thesis, California State University, Long Beach, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=1604882.
Testo completoAbstract (sommario):
Wireless sensor networks has been growing rapidly over the past few decades. Due to their flexibility, wireless sensor networks have been in practice in many areas. Unlike other network architectures, Mobile Ad hoc networks (MANETs) have no central architecture; every node is free to work both as a transmitter and receiver and it depends on neighboring nodes to send relay messages. Due to their advantages, MANETs are used in many different applications like health care and military. However the wide distribution of MANETs makes it vulnerable to malicious attacks. Hence it is necessary to design a secure system for MANETs. In this report, we implement a secure system named Enhanced Adaptive Acknowledgement especially for MANETs. To ensure higher security and reduce the network overhead and delay, we use a different approach called hybrid cryptography in our proposed scheme. Enhanced Adaptive Acknowledgment detects higher malicious attackers without greatly disturbing the network performances. In the simulation we compare the differences within the Enhanced Adaptive Acknowledgment (EAACK) before and after introducing the Hybrid cryptography approach.
13
Erramilli, Vijay. "Forewarding in Mobile Opportunistic Networks". Boston University Computer Science Department, 2009. https://hdl.handle.net/2144/1722.
Testo completoAbstract (sommario):
Recent advances in processor speeds, mobile communications and battery life have enabled computers to evolve from completely wired to completely mobile. In the most extreme case, all nodes are mobile and communication takes place at available opportunities – using both traditional communication infrastructure as well as the mobility of intermediate nodes. These are mobile opportunistic networks.
Data communication in such networks is a difficult problem, because of the dynamic underlying topology, the scarcity of network resources and the lack of global information. Establishing end-to-end routes in such networks is usually not feasible. Instead a store-and-carry forwarding paradigm is better suited for such networks. This dissertation describes and analyzes algorithms for forwarding of messages in such networks.
In order to design effective forwarding algorithms for mobile opportunistic networks, we start by first building an understanding of the set of all paths between nodes, which represent the available opportunities for any forwarding algorithm. Relying on real measurements, we enumerate paths between nodes and uncover what we refer to as the path explosion effect. The term path explosion refers to the fact that the number of paths between a randomly selected pair of nodes increases exponentially with time. We draw from the theory of epidemics to model and explain the path explosion effect. This is the first contribution of the thesis, and is a key observation that underlies subsequent results.
Our second contribution is the study of forwarding algorithms. For this, we rely on trace driven simulations of different algorithms that span a range of design dimensions. We compare the performance (success rate and average delay) of these algorithms. We make the surprising observation that most algorithms we consider have roughly similar performance. We explain this result in light of the path explosion phenomenon.
While the performance of most algorithms we studied was roughly the same, these algorithms differed in terms of cost. This prompted us to focus on designing algorithms with the explicit intent of reducing costs. For this, we cast the problem of forwarding as an optimal stopping problem. Our third main contribution is the design of strategies based on optimal stopping principles which we refer to as Delegation schemes. Our analysis shows that using a delegation scheme reduces cost over naive forwarding by a factor of O(√N), where N is the number of nodes in the network. We further validate this result on real traces, where the cost reduction observed is even greater.
Our results so far include a key assumption, which is unbounded buffers on nodes. Next, we relax this assumption, so that the problem shifts to one of prioritization of messages for transmission and dropping. Our fourth contribution is the study of message prioritization schemes, combined with forwarding. Our main result is that one achieves higher performance by assigning higher priorities to young messages in the network. We again interpret this result in light of the path explosion effect.Thomson Research, Paris; National Science Foundation (CCR-0325701, ANI-0322990); HAGGLE FET Project; Erramilli family.
14
Al-Bayatti, Ali Hilal. "Security management for mobile ad hoc network of networks (MANoN)". Thesis, De Montfort University, 2009. http://hdl.handle.net/2086/2417.
Testo completoAbstract (sommario):
Mobile Ad hoc Network of Networks (MANoN) are a group of large autonomous wireless nodes communicating on a peer-to-peer basis in a heterogeneous environment with no pre-defined infrastructure. In fact, each node by itself is an ad hoc network with its own management. MANoNs are evolvable systems, which mean each ad hoc network has the ability to perform separately under its own policies and management without affecting the main system; therefore, new ad hoc networks can emerge and disconnect from the MANoN without conflicting with the policies of other networks. The unique characteristics of MANoN makes such networks highly vulnerable to security attacks compared with wired networks or even normal mobile ad hoc networks. This thesis presents a novel security-management system based upon the Recommendation ITU-T M.3400, which is used to evaluate, report on the behaviour of our MANoN and then support complex services our system might need to accomplish. Our security management will concentrate on three essential components: Security Administration, Prevention and Detection and Containment and Recovery. In any system, providing one of those components is a problem; consequently, dealing with an infrastructure-less MANoN will be a dilemma, yet we approached each set group of these essentials independently, providing unusual solutions for each one of them but concentrating mainly on the prevention and detection category. The contributions of this research are threefold. First, we defined MANoN Security Architecture based upon the ITU-T Recommendations: X.800 and X.805. This security architecture provides a comprehensive, end-to-end security solution for MANoN that could be applied to every wireless network that satisfies a similar scenario, using such networks in order to predict, detect and correct security vulnerabilities. The security architecture identifies the security requirements needed, their objectives and the means by which they could be applied to every part of the MANoN, taking into consideration the different security attacks it could face. Second, realising the prevention component by implementing some of the security requirements identified in the Security Architecture, such as authentication, authorisation, availability, data confidentiality, data integrity and non-repudiation has been proposed by means of defining a novel Security Access Control Mechanism based on Threshold Cryptography Digital Certificates in MANoN. Network Simulator (NS-2) is a real network environment simulator, which is used to test the performance of the proposed security mechanism and demonstrate its effectiveness. Our ACM-MANoN results provide a fully distributed security protocol that provides a high level of secure, available, scalable, flexible and efficient management services for MANoN. The third contribution is realising the detection component, which is represented by providing a Behavioural Detection Mechanism based on nodes behavioural observation engaged with policies. This behaviour mechanism will be used to detect malicious nodes acting to bring the system down. This approach has been validated using an attacks case study in an unknown military environment to cope with misbehaving nodes.
15
Wang, Hao. "Performance modelling of network management schemes for mobile wireless networks". Thesis, University of Edinburgh, 2009. http://hdl.handle.net/1842/13192.
Testo completo
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Jeoun, Kristina S. "The tactical network operations communication coordinator in mobile UAV networks". Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2004. http://library.nps.navy.mil/uhtbin/hyperion/04Jun%5FJeoun.pdf.
Testo completo
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Ho, Yao Hua. "Connectionless approach--a localized scheme to mobile ad hoc networks". Orlando, Fla. : University of Central Florida, 2009. http://purl.fcla.edu/fcla/etd/CFE0002742.
Testo completo
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Shankaran, Rajan, University of Western Sydney, of Science Technology and Environment College e School of Computing and Information Technology. "Security issues in mobile IP and mobile ad hoc networks". THESIS_CSTE_CIT_Shankaran_R.xml, 2004. http://handle.uws.edu.au:8081/1959.7/585.
Testo completoAbstract (sommario):
The need for information anywhere and at any time has been the driving force for the increasing growth in mobile networks and devices. The field of mobile computing is the merger of advances in computing and communications with the aim of providing seamless and ubiquitous computing environment for mobile users. Whereas notebook computers and personal digital assistants (PDAs) are self-contained, networked computing constitutes a new paradigm of computing that is revolutionizing the way computers are used. Mobile networking greatly enhances the utility of carrying a computing device. It provides mobile users with versatile communication to other people and expedient notification of important events, yet with much more flexibility than cellular telephones and pagers. It also permits continuous access to services and resources of the traditional land-based wired networks. This combination of networking and mobility will engender new applications and services, such as collaborative software to support impromptu meetings, electronic bulletin boards that adapt to the contents according to the participants present, self adjusting lighting and heating, and navigation software to guide users in unfamiliar places and tours. To support mobility in the Internet, the Internet Protocol (IP) has been extended to support mobility. Also at the same time, there is also a growing trend for these IP based networks to operate in an infrastructureless environment called mobile ad-hoc networks. However, the proliferation of such mobile networks depends on a multitude of factors, with trustworthiness being one of the primary challenges to be met. The objective of this dissertation is to address the issues involved in the design of security services for Mobile IP and ad-hoc networks. Extensions to IP based networks (both wired and infrastructureless networks) to facilitate mobility have not been designed keeping security in mind. However adequate security features are basic requirements for the continued functioning of mobile networks. Clearly the problem is so broad that there is no way to devise a general solution We aim to address most of these wide- ranging problems and in the process initiate a practical approach to the development of an integrated security infrastructure for mobile networks. The intention is to seamlessly integrate these security services and mechanisms at the IP level within the mobile IP and ad-hoc networks. The provision of security services at the higher and lower layers and their interoperability with our proposed framework is outside the scope of this thesisDoctor of Philosophy (PhD)
19
Cherriman, Peter John. "Mobile video networking". Thesis, University of Southampton, 1998. https://eprints.soton.ac.uk/251962/.
Testo completo
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Chochlidakis, Georgios. "Mobility-aware virtual network embedding techniques for next-generation mobile networks". Thesis, King's College London (University of London), 2018. https://kclpure.kcl.ac.uk/portal/en/theses/mobilityaware-virtual-network-embedding-techniques-for-nextgeneration-mobile-networks(174e714f-2a4a-447a-bcd5-d526170377fd).html.
Testo completoAbstract (sommario):
Network virtualisation has become one of the most prominent solutions for sus-tainability towards the dramatic increase of data demand in next-generation mobile networks. In addition, apart from increasing the overall infrastructure utilisation, it also greatly improves the manageability, the scalability and the robustness of the network. In order to allow multiple virtual networks to coexist in the same substrate network, the need for efficient network sharing techniques is imperative. The main purpose of this work is to provide a holistic optimization framework for vir-tual network embedding solutions, where the actual user mobility effect is explicitly considered. First, the main focus is given on the study of the mobility effect and the impact of the mobility management techniques on the end-to-end communication of the mobile user. A hybrid-distributed mobility management scheme is proposed and compared against the latest mobility management schemes. Then, an optimisation framework for efficient mobility-aware virtual network embedding is proposed and evaluated by comparison with other works from the literature. Moving deeper in the area of virtual network embedding, the focus is given on minimizing the end-to-end delay and providing service differentiation, allowing in this way delay sensitive services to use the formed virtual networks with the minimum possible delay, as op-posed to other more elastic services that use the same substrate network. The last part of this work is the study and the analysis of the stochastic nature of the virtual network embedding parameters and the proposal of an optimisation framework for adjustable-robustness virtual network embedding. Driven by the benefits from virtualising the network and its functions, research as well as industry are expected to exploit in a greater degree than today the merits of this concept. The co-existence of multiple tenants not only will greatly change the network industry from a business perspective, but also will emphasise the need for more efficient and flexible network sharing techniques. This work belongs to the initial efforts to embrace and adopt the virtualisation concept in the next-generation wireless networks.
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Dharne, Avinash Gopal. "Issues in autonomous mobile sensor networks". [College Station, Tex. : Texas A&M University, 2007. http://hdl.handle.net/1969.1/ETD-TAMU-1343.
Testo completo
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Kobosko, Kristoffer, e Henrik Wallentin. "Mobile Groups in Ad-hoc Networks". Thesis, Uppsala University, Department of Information Technology, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-108036.
Testo completoAbstract (sommario):
Most current research on Mobile Ad-hoc NETworks (MANETs) concerns one ad-hocnetwork at a time. A common topic is how to handle the merging of new nodesappearing in range of an existing MANET into a new, larger network. CurrentMANET implementations do not define the handling of policies for controllingmembership or routing messages, neither do they support policy-based inter-MANETrouting.
In this thesis, we present an implementation of Mobile Group Protocol (MGP) whichenhances the reactive routing protocol AODV with an administrative framework inwhich Mobile Ad-hoc NETwork (MANET) policies are defined. Such policies are usedto control membership and signaling in a MANET. We define new roles for theMANET members such as nodes, leaders and gateways. We discuss the messageexchange taking place during forming of Mobile Groups (MGs) and study the theparticular implementation by simulating a group of simple MGP scenarios usingNetwork Simulator 2 (NS-2).
We conclude our work by discussing the using of MGP as a base for an inter-MANETrouting protocol providing policy-based routing in MANETs.
23
Karaminas, Panagiotis D. "Array processing in mobile radio networks". Thesis, Imperial College London, 2001. http://hdl.handle.net/10044/1/11483.
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Biswas, Subir Kumar. "Handling realtime traffic in mobile networks". Thesis, University of Cambridge, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.320943.
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Giortzis, Athanasios. "Channel assignment in mobile radio networks". Thesis, Imperial College London, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.266017.
Testo completo
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Kong, Chenguang, e 孔臣光. "Collaborative streaming in mobile social networks". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2011. http://hub.hku.hk/bib/B47849897.
Testo completoAbstract (sommario):
Mobile social applications have emerged in recent years. They explore social
connections among mobile users in a variety of novel scenarios, including
friend finding, message routing, and content sharing. However, efficiently supporting
resource-demanding delay-sensitive streaming applications on the mobile
platform remains a significant challenge. Research on such topics will naturally
widen the usage of mobile social applications. The solutions to the challenges
will provide suggestion on many related work. It is interesting and valuable to
explore the system performance and users’ experience in such scenarios.
Furthermore, users’ concern about social network is also significant to develop
a mobile social network application. It is important to detect users’ strategies
to communicate with others. That influences the network topologies and
provides biased connections. The strategy consists of various of aspects, most of
which are the user preference and user social attributes.
Focusing on this meaningful research field, we study collaborative VoD-type
streaming of short videos among small groups of mobile users, so as to effectively
exploit their social relationships. Such an application can be practically set in
a number of usage scenarios, including streaming of introductory video clips of
exhibition items to visitors’ mobile devices, such as in a museum. We analyze
users’ behavior strategies based on their social preference and social attributes.
We design SMS, an architecture that engineers such Streaming over Mobile Social
networks. SMS constructs a collaborative streaming overlay by carefully
inspecting social connections among users and infrastructure characteristics of
Bluetooth technologies. To improve the performance, we analyze the scatternet
structure of Bluetooth technology and propose appropriate scatternet structure
in our system. We evaluate our design based on prototype implementation on
the Android platform, as well as on a large emulation testbed. The results obtained
indicate that we are able to achieve a well-performed streaming system in
a mobile social network.published_or_final_version
Computer Science
Master
Master of Philosophy
27
Fabri, S. N. "Multimedia communications over mobile packet networks". Thesis, University of Surrey, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.343461.
Testo completoAbstract (sommario):
This thesis describes several concepts associated with the transmission of multimedia services over mobile radio access networks. The error performance and traffic requirements of real-time video transmission over the General Packet Radio Services (GPRS) access network and its successor Enhanced-GPRS is examined. In view of this. video error resilience techniques which exploit channel prioritisation mechanisms are introduced with a view to increasing the robustness of received video sequences encoded with MPEG-4 to channel errors. These include stream prioritisation using unequal error protection and region-of-interest prioritisation for use in multiparty communications and streaming applications. A new forward-error correction scheme for EGPRS which uses iterative serially-concatenated convolutional-Reed Solomon codes is designed and is shown to significantly enhance the error performance for real-time services. A study of (he use of backward error correction mechanisms when transmitting streaming multimedia services is carried out, and a new retransmission scheme is introduced to increase the capacity of the radio access network when supporting streaming services
28
Panaousis, Emmanouil A. "Security for mobile ad-hoc networks". Thesis, Kingston University, 2012. http://eprints.kingston.ac.uk/23989/.
Testo completoAbstract (sommario):
Ad-hoc networks are crucial enablers of next generation communications. Such networks can be formed and reconfigured dynamically and they can be mobile, standalone or inter-networked with other networks. Mobile Ad-hoc NETworks (MANETs) are established by group of autonomous nodes that communicate with each other by establishing a multihop radio network and maintain connectivity in an infrastructureless manner. Security of the connections between devices and networks is crucial. Current MANET routing protocols inherently trust all participants being cooperative by nature and they depend on neighbouring nodes to route packets to a destination. Such a model allows malicious nods to potentially harm MANET communications links or reveal confidential data by launching different kind of attacks. The main objective of this thesis is to investigate and propose security mechanisms for MANET communications mainly emphasising on emergency scenarios where first responders' devices communicate by establishing a decentralised wireless network. To this end, we have proposed security mechanisms for innovtive routing and peer-to-peer overlay mechanisms for emergency MANETs proposed supplementarily to the findings of this thesis. Such security mechanisms guarntee confidentiality and integrity of the emergency MANET communications. We have also proposed novel ways of improving availability in MANETs in presence of intrusion detection systems by increasing the nodes' lifetime based on a novel game theoretic routing protocol for MANETs. We have thoroughly evaluated the performance of all the proposed mechanisms using a network simulator. The main objective of undertaking these evaluations was to guarantee that security introduces affordable overhead thereby respecting the Quality-of-Service of MANET communication links.
29
Jiang, Menglan. "Traffic management in heterogeneous mobile networks". Thesis, King's College London (University of London), 2017. https://kclpure.kcl.ac.uk/portal/en/theses/traffic-management-in-heterogeneous-mobile-networks(42f0075f-9433-4593-adf1-9401f7e8276a).html.
Testo completoAbstract (sommario):
Enhancing the efficiency of traffic management and improving the network revenue for operators are the most essential issues in heterogeneous mobile networks. As the heterogeneous mobile network is composed of diverse network technologies, it is expected to offer effective network connections and sufficient network resources to increased number of mobile users with various traffic demands. Moreover, the price of each selling resources might vary significantly from the business point of view. Therefore, heterogeneous mobile networks aim to provide superior user experience, guarantee efficient resource utilisation and maximise mobile network revenue. The main objective of this thesis is to manage and allocate limited network resources to mobile users for improving their quality level and network revenue. The primary focus of this thesis is on developing valid network architecture for efficient resource allocation and designing novel optimisation algorithms for effective traffic management. Besides, the other focus of this thesis is on exploring future works in the field of traffic management in heterogeneous mobile networks. This thesis covers two aspects of traffic management from the mobile user side and the network side. With the motivation of ever increasing traffic demands in heterogeneous mobile networks, maintaining quality level of mobile users, improving resource utilisation and maximising network revenue are more than ever challenging. In this thesis, a fully distributed device- controlled network assisted mechanism for network selection has been developed. Decisions in this mechanism are made by mobile devices only. The device controlled mechanism mainly focuses on Quality of Service (QoS) requirements of mobile devices, while network information and location profiles are provided by the network assisted part. In order to improve the network performance, a novel semi-centralised QoS-based traffic management mechanism has been developed further. The semi-centralised mechanism aims to maintain the quality level of mobile users and guarantee the fairness among mobile users in heterogeneous mobile networks. Moreover, a novel prioritised admission control mechanism has been developed for network slicing. Network slicing, where virtualised network resources are packaged and assigned in an isolated manner to set of mobile users, is considered as a key paradigm to implement resource allocation based on diversity of resource requirements. The mechanism is heuristic based and contains two-tier priority level among different service slices and mobile users. The mechanism aims to maximise resource utilisation and guarantee the mobile users resource requirements. Apart from this, network slicing is also significant for the business model of operators. As as result, a novel economics based traffic management mechanism has been developed further. It aims to maximise the network revenue and enhance network utilisation in heterogeneous mobile networks. Finally, the thesis is concluded and some proper future researches are included as well.
30
Toh, Chai-Keong. "Protocol aspects of mobile radio networks". Thesis, University of Cambridge, 1996. https://www.repository.cam.ac.uk/handle/1810/273055.
Testo completo
31
Pietiläinen, Anna-Kaisa. "Opportunistic mobile social networks at work". Paris 6, 2010. http://www.theses.fr/2010PA066587.
Testo completoAbstract (sommario):
Les réseaux mobiles opportunistes ad-hoc se forment lorsque des terminaux mobiles portés par des utilisateurs communiquent entre eux sans aucune infrastructure. Ils diffèrent ainsi des réseaux classiques comme Internet dont l'architecture suppose la disponibilité instantanée de chemins reliant les hôtes et dont les délais de propagation, et le taux de perte des paquets, sont faibles. Dans les réseaux opportunistes, la mobilité des individus induit de nombreuses déconnexions et de grandes variations des délais. Dans cette thèse nous adoptons une démarche expérimentale pour concevoir et analyser les réseaux opportunistes. D'abord l'étude détaillée des communications opportunistes via Bluetooth dans des environnements contrôlés et réels, montre qu'en dépit des limitations pratiques de cette technologie, la communication opportuniste ad-hoc constitue un paradigme de communication efficace et attractif. Nous avons ensuite conçu et implémenté MobiClique, un middleware de communication destiné aux réseaux opportunistes qui s'appuie sur la mobilité et les relations sociales des utilisateurs pour le routage opportuniste des messages. Enfin, la réalisation d'une expérience grandeur nature mobilisant 80 personnes nous a permis de collecter les informations concernant leurs réseaux sociaux, leurs contacts ad-hoc et les traces de leurs communications. Nous proposons une méthodologie d'analyse des structures des communautés temporelles dans le réseau opportuniste. Nous étudions également de quelle façon ces structures et les interactions sociales caractérisent les chemins de dissémination du contenu.
32
Watson, Simon Andrew. "Mobile platforms for underwater sensor networks". Thesis, University of Manchester, 2012. https://www.research.manchester.ac.uk/portal/en/theses/mobile-platforms-for-underwater-sensor-networks(00f93130-f9d6-4479-80ab-58a0c60327c0).html.
Testo completoAbstract (sommario):
The production of clean water, the generation of nuclear power and the development of chemicals, petro-chemicals and pharmaceuticals all rely on liquid-based processes. They are fundamental to modern society, however the real-time monitoring of such processes is an inherently difficult challenge which has not yet been satisfactorily solved.Current methods of monitoring include on- and off-line spot checks and industrial process tomography. Neither of these methods provides the spatial or temporal resolution required to properly characterise the processes. This research project proposes a new monitoring method for processes which can tolerate foreign objects; a mobile underwater sensor network (MUSN).An MUSN has the potential to increase both the spatial and temporal resolution of measurements and could be used in real-time. The network would be formed by a number of mobile sensor platforms, in the form of micro-autonomous underwater vehicles (uAUVs) which would communicate using acoustics. The demonstrator for the technology is for use in the monitoring of nuclear storage ponds.Current AUV technology is not suitable for use in enclosed environments such as storage ponds due to the size and maneuverability. This thesis presents the research conducted in the development of a new vehicle uAUV. The work presented covers the mechatronic aspects of the vehicle; the design of the hull, propulsion systems, corresponding control circuitry and basic motion control systems. One of the main factors influencing the design of the vehicle has been cost. If a large number of vehicles are used to form a network, the cost of an individual uAUV should be kept as low as possible. This has raised a number of technical challenges as low-cost components are often of low-tolerance. Imbalanced time-varying thrust, low manufacturing tolerances and noisy indirect sensor measurements for the control systems have all been overcome in the design of the vehicle. The outcome of the research is a fully functional prototype uAUV. The vehicle is spherical in shape with a diameter of approximately 15cm, with six thruster units mounted around the equator (increasing the horizontal clearance to 20cm) to provide thrust in four degrees of freedom (surge, sway, heave and yaw). The vehicle has a sensor suite which includes a pressure sensor, digital compass and a gyroscope which provide inputs to the motion control systems. The controllers have been developed and implemented on the vehicle's custom built embedded system. Experiments have been conducted showing that the uAUV is able to move in 3D with closed-loop control in heave and yaw. Motion in surge and sway is open-loop, via a dead-reckoning system.
33
Ma, Wenchao. "Mobility management for wireless mobile networks". [Gainesville, Fla.] : University of Florida, 2003. http://purl.fcla.edu/fcla/etd/UFE0001252.
Testo completo
34
Xu, Ji. "Data caching in wireless mobile networks /". View abstract or full-text, 2004. http://library.ust.hk/cgi/db/thesis.pl?COMP%202004%20XU.
Testo completoAbstract (sommario):
Thesis (M. Phil.)--Hong Kong University of Science and Technology, 2004.Includes bibliographical references (leaves 57-60). Also available in electronic version. Access restricted to campus users.
35
Kumar, Kavitha. "Intrusion Detection in Mobile Adhoc Networks". Connect to full text in OhioLINK ETD Center, 2009. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=toledo1260232844.
Testo completoAbstract (sommario):
Thesis (M.S.)--University of Toledo, 2009.Typescript. "Submitted to the Graduate Faculty as partial fulfillment of the requirements for the Master of Science Degree in Engineering." "A thesis entitled"--at head of title. Bibliography: leaves 80-84.
36
Mosko, Marc Elliott. "Routing in mobile ad hoc networks /". Diss., Digital Dissertations Database. Restricted to UC campuses, 2004. http://uclibs.org/PID/11984.
Testo completo
37
Shigueta, Roni. "Channel Allocation in Mobile Wireless Networks". Thesis, Université Paris-Saclay (ComUE), 2018. http://www.theses.fr/2018SACLX037/document.
Testo completoAbstract (sommario):
L'utilisation intensive des services de données mobiles a de plus en plus augmenté la consommation de ressources sur les réseaux sans fil. La ressource principale utilisée pour la communication sans fil est le spectre de fréquence. À mesure que le trafic de données augmente brusquement, de nouvelles bandes du spectre de fréquences ne sont pas disponibles dans la même proportion, ce qui rend le spectre de fréquence de plus en plus rare et saturé. Plusieurs propositions ont été présentées pour optimiser l'allocation des canaux de fréquences afin d'atténuer les interférences entre les liaisons proches qui transmettent des données. Beaucoup d'entre eux utilisent un critère unique et ne considèrent pas le comportement de l'utilisateur pour guider le processus d'allocation de canaux. Les utilisateurs ont des cycles de routine et un comportement social. Ils passent au travail, à l'école, utilisent leurs appareils mobiles générant du trafic de données, et rencontrent des amis formant des groupes. Ces caractéristiques peuvent être explorées pour optimiser le processus d'allocation des canaux.Cette thèse présente une stratégie d'allocation de canaux pour les réseaux sans fil basée sur le comportement de l'utilisateur. Notre contribution principale consiste à considérer certaines caractéristiques du comportement de l'utilisateur, telles que la mobilité, le trafic et la popularité dans le processus d'allocation des canaux. De cette façon, nous priorisons l'allocation de canaux pour les nœuds qui resteront dans le réseau dans une fenêtre de temps future, avec un trafic plus élevé dans le réseau, et avec plus de popularité. Nous adoptons une approche distribuée qui permet de limiter le nombre de messages échangés dans le réseau tout en répondant rapidement aux changements de la topologie du réseau. Dans notre évaluation des performances, nous considérons des scénarios dans des réseaux ad hoc et véhiculaires, et nous utilisons des modèles de mobilité synthétique, tels que SLAW et Manhattan grid, et l'ensemble de données de traces de ville de Cologne. Dans les scénarios, nous comparons notre mécanisme avec différents types de techniques : une centralisée (nommée TABU), une autre aléatoire (nommée RANDOM), une avec la plus grande distance spectrale (appelée LD) et une avec un seul canal (appelée SC). Nous évaluons les métriques telles que le débit agrégé, le débit de livraison des paquets et le délai de bout en bout.Les simulations envisageant un scénario ad hoc avec un routage monodiffusion montrent que notre stratégie présente des améliorations en termes de débit de l'ordre de 14,81% par rapport à RANDOM et de 16,28% par rapport à l'allocation de canal LD. Dans le scénario véhiculaire, notre stratégie montre des gains de taux de livraison de paquets de l'ordre de 11,65% et de 17,18% par rapport aux méthodes RANDOM et SC, respectivement. Dans ces deux scénarios, la performance de notre stratégie est proche de la limite supérieure donnée par l'approche centralisée de TABU, mais avec l’envoie de moins des messagesThe intensive use of mobile data services has increasingly increased resource consumption over wireless networks. The main resource used for wireless communication is the frequency spectrum. As data traffic rises sharply, new bands of the frequency spectrum are not available in the same proportion, making the frequency spectrum increasingly scarce and saturated. Several proposals have been presented to optimize frequency channel allocation in order to mitigate interference between nearby links that are transmitting data. Many of them use a single criterion and does not consider the user behavior to guide the channel allocation process. Users have routine cycles and social behavior. They routinary move to work, to school, use their mobile devices generating data traffic, and they meet with friends forming clusters. These characteristics can be explored to optimize the channel allocation process.This thesis presents a channel allocation strategy for wireless networks based on user behavior. Our main contribution is to consider some characteristics of the user behavior, such as mobility, traffic, and popularity in the channel allocation process. In this way, we prioritize the channel allocation for the nodes that will remain in the network in a future time window, with higher traffic in the network, and with more popularity. We adopt a distributed approach that allows limiting the number of messages exchanged in the network while quickly responding to changes in the network topology. In our performance evaluation, we consider scenarios in ad hoc and vehicular networks, and we use some synthetic mobility models, such as SLAW and Manhattan grid, and the traces dataset of Cologne city. In the scenarios, we compare our mechanism with different types of approaches: i.e., a centralized (named TABU), a random (named RANDOM), a with largest spectral distance (named LD), and a with single channel (named SC). We evaluate metrics such as aggregated throughput, packet delivery rate, and end-to-end delay. Simulations considering ad hoc scenario with unicast routing show that our strategy presents improvements in terms of throughput at the order of 14.81% than RANDOM and 16.28% than LD channel allocation. In vehicular scenario, our strategy shows gains of packet delivery rate at the order of 11.65% and 17.18% when compared to RANDOM and SC methods, respectively. In both scenarios, the performance of our strategy is close to the upper bound search of the TABU centralized approach, but with lower overhead
38
Tin, Yiu Shing (Terry). "Secure key establishment for mobile networks". Thesis, Queensland University of Technology, 2005. https://eprints.qut.edu.au/16035/1/Yiu_Shing_Tin_Thesis.pdf.
Testo completoAbstract (sommario):
Informal analysis of authenticated key establishment (ake) protocols was commonly accepted as the valid argument for their security in the past. Although it can provide some confidence in protocol correctness, experience has shown time and again that ake protocols are likely to contain flaws even after an informal analysis is completed. Therefore, it has become increasingly common to expect a formal analysis, and preferably a mathematical proof, of any published ake protocol in order to obtain increased confidence in its security. In this research we use an appropriate model for analysing ake protocols based on its features and properties. The model allows us to design ake protocols modularly and reuse existing protocol components. We provide a detailed description of its formalisation, operations and usage. This description also includes ways of extracting new protocol components from existing ake protocols. Following the description of the model, we propose a new unauthenticated key establishment protocol for two-party communications. By composing this protocol with authentication protocols, we can construct several new secure ake protocols. These new protocols are compared with existing protocols for their computational efficiency. The comparison shows that our new proven secure protocols are as efficient as the existing protocols with an informal security analysis. We then propose a three-party key establishment protocol which involves a trusted server and two users. We also propose a non-interactive authentication protocol and discuss it and a variant of it. These components are used to construct a secure three-party ake protocol that supports a privacy framework. This framework allows users to remain anonymous while conducting electronic transactions with an independent service provider. A new password-based authentication protocol is proposed to address the problem of authentication using passwords. This protocol carries a proof of security and satisfies a slightly relaxed definition of security. We demonstrate its application by composing it with existing key establishment protocols. To maximise its use, we modified a two-party key establishment protocol to become three-party server based. By using the server for authentication, two users within a common network domain can establish a secure session key. Only a small number of ake protocols are demonstrated in this thesis. There exist many more provably secure ake protocols that can be constructed using the protocol components presented by applying the approach of "mix and match". That is, each new component results in a number of new ake protocols depending on the number of existing components.
39
Tin, Yiu Shing (Terry). "Secure Key Establishment for Mobile Networks". Queensland University of Technology, 2005. http://eprints.qut.edu.au/16035/.
Testo completoAbstract (sommario):
Informal analysis of authenticated key establishment (ake) protocols was commonly accepted as the valid argument for their security in the past. Although it can provide some confidence in protocol correctness, experience has shown time and again that ake protocols are likely to contain flaws even after an informal analysis is completed. Therefore, it has become increasingly common to expect a formal analysis, and preferably a mathematical proof, of any published ake protocol in order to obtain increased confidence in its security. In this research we use an appropriate model for analysing ake protocols based on its features and properties. The model allows us to design ake protocols modularly and reuse existing protocol components. We provide a detailed description of its formalisation, operations and usage. This description also includes ways of extracting new protocol components from existing ake protocols. Following the description of the model, we propose a new unauthenticated key establishment protocol for two-party communications. By composing this protocol with authentication protocols, we can construct several new secure ake protocols. These new protocols are compared with existing protocols for their computational efficiency. The comparison shows that our new proven secure protocols are as efficient as the existing protocols with an informal security analysis. We then propose a three-party key establishment protocol which involves a trusted server and two users. We also propose a non-interactive authentication protocol and discuss it and a variant of it. These components are used to construct a secure three-party ake protocol that supports a privacy framework. This framework allows users to remain anonymous while conducting electronic transactions with an independent service provider. A new password-based authentication protocol is proposed to address the problem of authentication using passwords. This protocol carries a proof of security and satisfies a slightly relaxed definition of security. We demonstrate its application by composing it with existing key establishment protocols. To maximise its use, we modified a two-party key establishment protocol to become three-party server based. By using the server for authentication, two users within a common network domain can establish a secure session key. Only a small number of ake protocols are demonstrated in this thesis. There exist many more provably secure ake protocols that can be constructed using the protocol components presented by applying the approach of "mix and match". That is, each new component results in a number of new ake protocols depending on the number of existing components.
40
Kobo, Hlabishi. "Situation-aware routing for wireless mesh networks with mobile nodes". Thesis, University of the Western Cape, 2012. http://etd.uwc.ac.za/index.php?module=etd&action=viewtitle&id=gen8Srv25Nme4_6647_1370594682.
Testo completo
41
Zhao, Xiaogeng. "An adaptive approach for optimized opportunistic routing over Delay Tolerant Mobile Ad hoc Networks". Thesis, Rhodes University, 2008. http://hdl.handle.net/10962/d1004822.
Testo completoAbstract (sommario):
This thesis presents a framework for investigating opportunistic routing in Delay Tolerant Mobile Ad hoc Networks (DTMANETs), and introduces the concept of an Opportunistic Confidence Index (OCI). The OCI enables multiple opportunistic routing protocols to be applied as an adaptive group to improve DTMANET routing reliability, performance, and efficiency. The DTMANET is a recently acknowledged networkarchitecture, which is designed to address the challenging and marginal environments created by adaptive, mobile, and unreliable network node presence. Because of its ad hoc and autonomic nature, routing in a DTMANET is a very challenging problem. The design of routing protocols in such environments, which ensure a high percentage delivery rate (reliability), achieve a reasonable delivery time (performance), and at the same time maintain an acceptable communication overhead (efficiency), is of fundamental consequence to the usefulness of DTMANETs. In recent years, a number of investigations into DTMANET routing have been conducted, resulting in the emergence of a class of routing known as opportunistic routing protocols. Current research into opportunistic routing has exposed opportunities for positive impacts on DTMANET routing. To date, most investigations have concentrated upon one or other of the quality metrics of reliability, performance, or efficiency, while some approaches have pursued a balance of these metrics through assumptions of a high level of global knowledge and/or uniform mobile device behaviours. No prior research that we are aware of has studied the connection between multiple opportunistic elements and their influences upon one another, and none has demonstrated the possibility of modelling and using multiple different opportunistic elements as an adaptive group to aid the routing process in a DTMANET. This thesis investigates OCI opportunities and their viability through the design of an extensible simulation environment, which makes use of methods and techniques such as abstract modelling, opportunistic element simplification and isolation, random attribute generation and assignment, localized knowledge sharing, automated scenario generation, intelligent weight assignment and/or opportunistic element permutation. These methods and techniques are incorporated at both data acquisition and analysis phases. Our results show a significant improvement in all three metric categories. In one of the most applicable scenarios tested, OCI yielded a 31.05% message delivery increase (reliability improvement), 22.18% message delivery time reduction (performance improvement), and 73.64% routing depth decrement (efficiency improvement). We are able to conclude that the OCI approach is feasible across a range of scenarios, and that the use of multiple opportunistic elements to aid decision-making processes in DTMANET environments has value.
42
Rogers, Paul Edward. "On robustness in high load mobile ad hoc networks". Diss., Online access via UMI:, 2005.
Cerca il testo completo
43
Pedersen, Finn. "Exploring Mobile TV in Sweden using Value Networks". Thesis, University of Gävle, Department of Business Administration and Economics, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-4046.
Testo completoAbstract (sommario):
Mobile TV is an application which has not yet been much described in academic literature. But the media and telecommunications industries are busy with Mobile TV deployment, motivated by for example decrease in revenues from existing products. This study should be seen as an exploratory study in the academia, aiming at a context for the experiences from exploratory work in the industry.
The study of the status of the application Mobile TV focused on legislation, spectra, content and terminals. These areas are of great interest for the telecom and the media industries, and their interests were described with regards to Mobile TV. Large structures like local legislation, spectral resource management on EU level and charging for content becomes visible and are discussed. On a lower level, two differences between the industries were high-lighted. One is the way revenue is collected for content, and the other is information sharing about the Consumers preferences. Overcoming these differences would ease collaboration. Another business topic for the two industries is the relation between the SIM card (which manifest the subscription) and the charging for content.A value network model which satisfies the legal, technical and business requirements is presented. In particular, a new role as Content Site Provider is identified. Since the interviewees suggested a future hybrid solution, both Mobile TV via streaming and via broadcast are included in the model.It is concluded that the telecom industry had all the means and incentive to create Mobile TV. It is also concluded that the process of digitalization is an ongoing process which continues to have an impact on the two industries, in that different offerings can be bundled together. One possible scenario is an Internet-like evolution of the mobile Internet, the Consumers will learn to find the applications closer to the source. This would make a broadcast solution less likely. The higher cost for over-the-air transmission is one obstacle for this scenario, but it might vanish with next generation mobile networks.
44
Kuhr, Mark Gregory Hamilton John A. "An adaptive jam-resistant cross-layer protocol for mobile ad-hoc networks In noisy environments". Auburn, Ala., 2009. http://hdl.handle.net/10415/1611.
Testo completo
45
Baig, Adeel Computer Science & Engineering Faculty of Engineering UNSW. "Improving throughput and fairness of on-board mobile networks". Awarded by:University of New South Wales. School of Computer Science & Engineering, 2007. http://handle.unsw.edu.au/1959.4/28247.
Testo completoAbstract (sommario):
The Internet Engineering Task Force (IETF) has recently released network mobility standards that allow deployment of TCP/IP networks onboard a vehicle and maintain permanent network connectivity to the Internet via a vehicular mobile router. This recent development opens up new opportunities for providing efficient mobile computing for users on the move, especially for commuters traveling on public transports. Moreover, central and coordinated management of mobility in a single router, rather than by each user device individually, has numerous advantages. In this architecture, however, it becomes challenging to guarantee network performance due to the mobility of the network and inherently vulnerable nature of wireless links. In this thesis, a detailed performance study of onboard networks is conducted. It has been shown that disruptions in the mobile router connectivity can significantly degrade network throughput. Moreover, factors such as the limited wireless bandwidth of the access link, variations in the bandwidth due to technology switching, and the communication diversity of onboard users all contribute to the problem of unfair sharing of wireless bandwidth. By leveraging the fact that all onboard communications go through the mobile router, performance enhancing solutions are proposed that can be deployed in the mobile router to transparently address the throughput and fairness problems. In this architecture, when the route is known in advance and repetitive (e.g. for public transport or a regularly commuting private vehicle), a certain degree of prediction of impending link disruptions is possible. An anticipatory state freezing mechanism is proposed that relies on the prediction of link disruptions to freeze and unfreeze the state machine of TCP, the widely used transport protocol in the Internet. Simulation study shows that TCP throughput has a non-linear relationship with the prediction accuracy. As prediction accuracy increases, throughput problem diminishes quickly. An adaptive mobile router based fairness control mechanism is proposed to address the unfair sharing of wireless bandwidth in highly dynamic scenarios. The fairness is controlled by dynamically estimating the round-trip-times of all onboard TCP connections and transparently adjusting the protocol control parameters at the router. The thesis also discusses implementation issues for the proposed solutions.
46
Sousa, Ângelo Miguel Raposo Almeida e. "Forecasting key performance indicator of mobile networks: application to mobile cellular networks". Master's thesis, 2019. http://hdl.handle.net/10773/29563.
Testo completoAbstract (sommario):
The increase of data trafic in the world has increased the need for mobile
network operators to take greater care in planning and managing theirs
infrastructures. This work explores the performance of several statistical
forecasting models aplied in voice and data trafic. This data was obtained
from an European mobile network, and, regarding the predictive models, it
was applied classic models like exponential smoothing, Holt-Winters, ARIMA,
Random-Walk; as well as two more recent model proposals. Regarding
the daily data, the proposed model could predict values with higher precision
compared to the other models. For hourly data, depending on the time
zone where the models were tested, the models with higher performance were
Random-Walk and the second proposed model. In summary, this dissertation
shows the performance of several classic statistical models, and how these
compare to recently proposed models. It also shows that mobile network
operator can use statistical forecasting methods to try to get information on
how their network might react in future, giving valueable insights to perform
a better managment of their network.O aumento do tráfego de dados no mundo, aumentou a necessidade dos operadores de redes móveis terem um maior cuidado a planear e gerir as suas infraestruturas. Este trabalho explora o desempenho de vários modelos estatísticos de previsão aplicados a tráfego de voz e de dados. Os dados têm origem numa rede móvel Europeia. Relativamente aos modelos preditivos, foram aplicados modelos clássicos como alisamento exponencial, Holt-Winters, ARIMA, Random-Walk; bem como duas propostas de modelos mais recentes. Em suma, esta dissertação mostra o desempenho de alguns modelos estatísticos clássicos, e como estes se comparam a modelos recentemente propostos. Também mostra que operadores de redes podem usar métodos preditivos estatísticos para tentar obter informações de como a sua rede pode reagir no futuro, dando assim informações valiosas para que estes efetuem uma melhor gestão da sua rede.
Mestrado em Engenharia Eletrónica e Telecomunicações
47
Chang-Jung, Kao, e 高長榮. "TCP in Mobile Networks". Thesis, 2002. http://ndltd.ncl.edu.tw/handle/29675103936203373345.
Testo completoAbstract (sommario):
碩士國立臺灣大學
電機工程學研究所
90
Advent technology of mobile computing devices has accelerated the development of wireless networks in recent years. To date, mobile devices, such as notebooks, mobile phones, and PDAs, can connect to the Internet via specific wireless network system nowadays. However, due to the feature of mobility in the mobile devices, there are different characteristics compared with the wired one, such as higher bit error rate in the wireless link and temporary data disconnection due to handoff between base stations. In wireless environments, the protocols designed for wired network might degrade their performance due to the effects mentioned above. Thus, the issues of TCP in mobile networks will be studied in this thesis. TCP had been designed in wired networks to provide reliable and ordered data transmission service. However, TCP degrades its performance due to the features of high bit error rate and mobility when being adopted in mobile devices. Consequently, this thesis attempts to propose a solution to the problems. The main contribution of this thesis is to propose a new sender-side TCP extension mechanism to solve the inefficient bandwidth utilization resulting from handoff. In addition, we also simulate the performance of the proposed mechanism. The results prove the enhancement of bandwidth efficiency by adopting the proposed mechanism in TCP sender.
48
Lu, Chang-che, e 呂長哲. "Location-based Network Management System for Heterogeneous Mobile Networks". Thesis, 2007. http://ndltd.ncl.edu.tw/handle/35186404723344553357.
Testo completoAbstract (sommario):
碩士國立中央大學
資訊工程研究所
95
With the improvement of society, the technology of internet is growing constantly. New wireless internet agreement like IEEE 802.11 (Wi-Fi) 、 IEEE 802.16 (WiMAX) and 3GPP (3rd Generation Partnership Project) provide internet users have different options for different broadband, different internet field and different prices. Many different wireless internet form an internet environment. We called it Heterogeneous wireless network environment. With new internet agreement getting mature, a variety of broadband wireless equipment is developed. To administer heterogeneous wireless network is becoming a significant issue when we face so many internet equipment at the same time. Traditional internet administration should be improved to manage heterogeneous wireless network environment. The most important problem in the administration of heterogeneous wireless network is how to administer many wireless networks at the same time. And it’s quite difficult to let internet administration center know the status of each wireless internet correctly and fast. Therefore, the essay offers a management system which applied to Heterogeneous wireless network. (Heterogeneous Mobile Network Management System，call the HMNMS). The system uses separated construction to set up a HMNMS on every different mobile wireless network. Every HMNMS will be able to share the information of Mobile Network with neighboring HMNMS. To measure intensity of message for bigger shooting range base with the location of smaller shooting range base. Making good use of several interfaces to decrease unnecessary cost on measurement. The system not only offers a convenient monitoring and manages wireless network equipment under Heterogeneous Mobile Network, but also analyze covering range of base through the intensity of message of the users and the location of users. With proper adjustment and the setting up of base location, to create the environment that internet exists everywhere.
49
Maji, A. "Load Balancing in Wireless Mobile Ad Hoc Networks". Thesis, 2010. http://ethesis.nitrkl.ac.in/1679/1/LOAD_BALANCING__(2).pdf.
Testo completoAbstract (sommario):
Ad hoc networks consist of a set of homogeneous nodes (computers or embedded devices) that move in an independent fashion and communicate with the other node in the topology over a wireless channel. Such networks are logically realized as a set of clusters by grouping together nodes which are in close proximity with one another or through another wireless node. Clusters are formed by clubbing together nodes along the wireless links. Cluster Heads are the nodes which communicate with the other nodes that it can cover under its communication range. Cluster Heads form a virtual backbone and may be used to route packets for nodes in their cluster. Nodes, being in an Ad Hoc network, are presumed to have a non-deterministic mobility pattern. Different heuristics employ different policies to elect Cluster Heads. Many of these policies are biased in favor of some nodes. As a result, these nodes shoulder greater responsibility which may deplete their energy faster due higher number of communication made, causing them to drop out of the network. Therefore, there is a need for load-balancing among Cluster Heads to allow all nodes the opportunity to serve as a Cluster Head. I propose a few enhancements to existing algorithms to remove the unbalanced distribution of nodes under the Cluster Heads and increase the active life of a node in a network.
50
Dolev, Shlomi, Seth Gilbert, Nancy A. Lynch, Elad Schiller, Alex A. Shvarstman e Jennifer Welch. "Virtual Mobile Nodes for Mobile Ad Hoc Networks". 2004. http://hdl.handle.net/1721.1/30450.
Testo completoAbstract (sommario):
One of the most significant challenges introduced by mobile networks is the difficulty in coping withthe unpredictable movement of mobile nodes. If, instead, the mobile nodes could be programmed totravel through the world in a predictable and useful manner, the task of designing algorithms for mobilenetworks would be significantly simplified. Alas, users of mobile devices in the real world are notamenable to following instructions as to where their devices may travel.While real mobile nodes may be disinclined to move as desired, we propose executing algorithmson virtual mobile nodes that move in a predetermined, predictable, manner through the real world. Inthis paper, we define the Virtual Mobile Node Abstraction, and present selected algorithms that takeadvantage of virtual mobile nodes to simply and efficiently perform complicated tasks in highly dynamic,unpredictable mobile ad hoc networks.We then present the Mobile Point Emulator, a new algorithm that implements robust virtual mobilenodes. This algorithm replicates the virtual node at a constantly changing set of real nodes, choosingnew replicas as the real nodes move in and out of the path of the virtual node. We claim that the MobilePoint algorithm correctly implements a virtual mobile node, and that it is robust as long as the virtualnode travels through well-populated areas of the network.