Generic Models for Mobility Management in Next Generation Networks

In the network community different mobility management techniques have been proposed over the years. However, many of these techniques share a surprisingly high number of similarities. In this technical report we analyze and evaluate the most relevant mobility management techniques, pointing out differences and similarities. For macro-mobility we consider Mobile IP (MIP), the Session Initiation Protocol (SIP) and mobility management techniques typical of a GSM network; for micro-mobility we describe and analyze several protocols such as: Hierarchical MIP, TeleMIP, IDMP, Cellular IP and HAWAII

Pervasive service discovery in low-power and lossy networks

Pervasive Service Discovery (SD) in Low-power and Lossy Networks (LLNs) is expected to play a major role in realising the Internet of Things (IoT) vision. Such a vision aims to expand the current Internet to interconnect billions of miniature smart objects that sense and act on our surroundings in a way that will revolutionise the future. The pervasiveness and heterogeneity of such low-power devices requires robust, automatic, interoperable and scalable deployment and operability solutions. At the same time, the limitations of such constrained devices impose strict challenges regarding complexity, energy consumption, time-efficiency and mobility. This research contributes new lightweight solutions to facilitate automatic deployment and operability of LLNs. It mainly tackles the aforementioned challenges through the proposition of novel component-based, automatic and efficient SD solutions that ensure extensibility and adaptability to various LLN environments. Building upon such architecture, a first fully-distributed, hybrid pushpull SD solution dubbed EADP (Extensible Adaptable Discovery Protocol) is proposed based on the well-known Trickle algorithm. Motivated by EADPs’ achievements, new methods to optimise Trickle are introduced. Such methods allow Trickle to encompass a wide range of algorithms and extend its usage to new application domains. One of the new applications is concretized in the TrickleSD protocol aiming to build automatic, reliable, scalable, and time-efficient SD. To optimise the energy efficiency of TrickleSD, two mechanisms improving broadcast communication in LLNs are proposed. Finally, interoperable standards-based SD in the IoT is demonstrated, and methods combining zero-configuration operations with infrastructure-based solutions are proposed. Experimental evaluations of the above contributions reveal that it is possible to achieve automatic, cost-effective, time-efficient, lightweight, and interoperable SD in LLNs. These achievements open novel perspectives for zero-configuration capabilities in the IoT and promise to bring the ‘things’ to all people everywhere

Descoberta de serviços independentes do acesso para redes heterogéneas

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

Mobility management in next generation networks

Master'sMASTER OF ENGINEERIN

Wireless Multi Hop Access Networks and Protocols

As more and more applications and services in our society now depend on the Internet, it is important that dynamically deployed wireless multi hop networks are able to gain access to the Internet and other infrastructure networks and services. This thesis proposes and evaluates solutions for providing multi hop Internet Access. It investigates how ad hoc networks can be combined with wireless and mesh networks in order to create wireless multi hop access networks. When several access points to the Internet are available, and the mobile node roams to a new access point, the node has to make a decision when and how to change its point of attachment. The thesis describes how to consider the rapid fluctuations of the wireless medium, how to handle the fact that other nodes on the path to the access point are also mobile which results in frequent link and route breaks, and the impact the change of attachment has on already existing connections. Medium access and routing protocols have been developed that consider both the long term and the short term variations of a mobile wireless network. The long term variations consider the fact that as nodes are mobile, links will frequently break and new links appear and thus the network topology map is constantly redrawn. The short term variations consider the rapid fluctuations of the wireless channel caused by mobility and multi path propagation deviations. In order to achieve diversity forwarding, protocols are presented which consider the network topology and the state of the wireless channel when decisions about forwarding need to be made. The medium access protocols are able to perform multi dimensional fast link adaptation on a per packet level with forwarding considerations. This i ncludes power, rate, code and channel adaptation. This will enable the type of performance improvements that are of significant importance for the success of multi hop wireless networks

Test and measurement environments for VANETs and MANETs

Mestrado em Engenharia de Computadores e TelemáticaA crescente necessidade por parte dos utilizadores em obterem acesso à Internet “em qualquer lugar e qualquer momento” tem incentivado investiga ção e desenvolvimento de abordagens capazes de resolver esta questão. Um dos maiores obstáculos em fornecer uma solução de acesso ubíquo à Internet tem sido a gestão de mobilidade. Nesta Tese de Mestrado ir-se-á implementar uma das soluções correntemente em desenvolvimento, integrando-a num ambiente MANET. A plataforma resultante pode ser posteriormente avaliada e até retiradas medidas de desempenho, podendo-se ainda tirar conclusões importantes sobre como um ambiente MANET se comporta numa plataforma de mobilidade global e acesso ubíquo. Na àrea de Sistemas de Transporte Inteligentes, tópicos como eficiência de tráfego e segurança dos utilizadores têm-se mostrado muito populares e deram in´ıcio a pesquisa extensiva em Redes Veículares Ad-Hoc (VANETs). Métodos tradicionais para investigação e desenvolvimento como testes com protótipos ou simulação computacional têm sido largamente usados. No entanto, os testes com protótipos são usualmente muito caros e a simulação computacional tem falta de precisão em ambientes sem fios. Esta Tese de Mestrado tem também por objectivo construir uma solução híbrida que combine os métodos de emulação e simulação. A solução proposta será implementada num testbed para VANETs. O testbed resultante irá permitir que multiplas instâncias de programas de routing reais possam ser executadas sobre um ambiente simulado computacionalmente. Assim poderão ser também retiradas elacções sobre o seu desempenho em características como o consumo de recursos e escalabilidade. ABSTRACT: The growing need from users to have internet access “whenever and wherever” has driven research to devise several approaches to cope with this issue. One of the greatest challenges in providing ubiquitous internet access has been the management of mobility. In this Master Thesis a solution currently under development, will be implemented integrating a MANET environment. The resulting testbed can later be evaluated and it’s performance measured, drawing important conclusions about how a MANET environment behaves in a global mobility and ubiquitous access framework. In the area of Intelligent Transportation System traffic efficiency and safety for users have become very popular topics and have triggered extensive research in Vehicular Ad-Hoc Networks (VANETs). Traditional methods for reaserch and development like field testing and simulation have been used. But field testing is usually very expensive expensive and simulation lacks accuracy in wireless environments. This Master Thesis also aims to provide a hybrid solution that combines the simulation and emulation methods. The proposed solution is implemented in a testbed for VANETs. The resulting testbed would allow multiple real routing instances to run simultaneously on a simulated environment. And to provide performance measures such as resource consumption and scalability

Adaptive load balancing routing algorithms for the next generation wireless telecommunications networks

This thesis was submitted for the degree of Doctor of Philosophy and was awarded by Brunel UniversityWith the rapid development of wireless networks, mesh networks are evolving as a new important technology, presenting a high research and commercial interest. Additionally, wireless mesh networks have a wide variety of applications, offering the ability to provide network access in both rural and urban areas with low cost of maintenance. One of the main functionalities of a wireless mesh network is load balancing routing, which is the procedure of finding the best, according to some criteria, routes that data need to follow to transfer from one node to another. Routing is one of the state-of-the-art areas of research because the current algorithms and protocols are not efficient and effective due to the diversity of the characteristics of these networks. In this thesis, two new routing algorithms have been developed for No Intra-Cell Interference (NICI) and Limited Intra-Cell Interference (LICI) networks based on WiMAX, the most advanced wireless technology ready for deployment. The algorithms created are based on the classical Dijkstra and Ford-Fulkerson algorithms and can be implemented in the cases of unicast and multicast transmission respectively.State scholarships foundation of Greece

Enabling Multipath and Multicast Data Transmission in Legacy and Future Internet

The quickly growing community of Internet users is requesting multiple applications and services. At the same time the structure of the network is changing. From the performance point of view, there is a tight interplay between the application and the network design. The network must be constructed to provide an adequate performance of the target application. In this thesis we consider how to improve the quality of users' experience concentrating on two popular and resource-consuming applications: bulk data transfer and real-time video streaming. We share our view on the techniques which enable feasibility and deployability of the network functionality leading to unquestionable performance improvement for the corresponding applications. Modern mobile devices, equipped with several network interfaces, as well as multihomed residential Internet hosts are capable of maintaining multiple simultaneous attachments to the network. We propose to enable simultaneous multipath data transmission in order to increase throughput and speed up such bandwidth-demanding applications as, for example, file download. We design an extension for Host Identity Protocol (mHIP), and propose a multipath data scheduling solution on a wedge layer between IP and transport, which effectively distributes packets from a TCP connection over available paths. We support our protocol with a congestion control scheme and prove its ability to compete in a friendly manner against the legacy network protocols. Moreover, applying game-theoretic analytical modelling we investigate how the multihomed HIP multipath-enabled hosts coexist in the shared network. The number of real-time applications grows quickly. Efficient and reliable transport of multimedia content is a critical issue of today's IP network design. In this thesis we solve scalability issues of the multicast dissemination trees controlled by the hybrid error correction. We propose a scalable multicast architecture for potentially large overlay networks. Our techniques address suboptimality of the adaptive hybrid error correction (AHEC) scheme in the multicast scenarios. A hierarchical multi-stage multicast tree topology is constructed in order to improve the performance of AHEC and guarantee QoS for the multicast clients. We choose an evolutionary networking approach that has the potential to lower the required resources for multimedia applications by utilizing the error-correction domain separation paradigm in combination with selective insertion of the supplementary data from parallel networks, when the corresponding content is available. Clearly both multipath data transmission and multicast content dissemination are the future Internet trends. We study multiple problems related to the deployment of these methods.Internetin nopeasti kasvava käyttäjäkunta vaatii verkolta yhä enemmän sovelluksia ja palveluita. Samaan aikaan verkon rakenne muuttuu. Suorituskyvyn näkökulmasta on olemassa selvä vuorovaikutussovellusten ja verkon suunnittelun välillä. Verkko on rakennettava siten, että se pystyy takaamaan riittävän suorituskyvyn halutuille palveluille. Tässä väitöskirjassa pohditaan, miten verkon käyttökokemusta voidaan parantaa keskittyen kahteen suosittuun ja resursseja vaativaan sovellukseen: tiedonsiirtoon ja reaaliaikaiseen videon suoratoistoon. Esitämme näkemyksemme tekniikoista, jotka mahdollistavat tarvittavien verkkotoiminnallisuuksien helpon toteuttavuuden sekä kiistatta parantavat sovelluksien suorityskykyä. Nykyaikaiset mobiililaitteet monine verkkoyhteyksineen, kuten myös kotitietokoneet, pystyvät ylläpitämään monta internet-yhteyttä samanaikaisesti. Siksi ehdotamme monikanavaisen tiedonsiirron käyttöä suorituskyvyn parantamiseksi ja etenkin vaativien verkkosovelluksien, kuten tiedostonsiirron, nopeuttamiseksi. Tässä väitöskirjassa suunnitellaan Host Identity Protocol (mHIP) -laajennus, sekä esitetään tiedonsiirron vuorotteluratkaisu, joka hajauttaa TCP-yhteyden tiedonsiirtopaketit käytettävissä oleville kanaville. Protokollamme tueksi luomme myös ruuhkautumishallinta-algoritmin ja näytämme sen pystyvän toimimaan yhteen nykyisien verkkoprotokollien kanssa. Tämän lisäksi tutkimme peliteoreettista mallinnusta käyttäen, miten monikanavaiset HIP-verkkopäätteet toimivat muiden kanssa jaetuissa verkoissa. Reaaliaikaisten sovellusten määrä kasvaa nopeasti. Tehokas ja luotettava multimediasisällön siirto on olennainen vaatimus nykypäivän IP-verkoissa. Tässä työssä ratkaistaan monilähetyksen (multicast) jakelustruktuurin skaalautuvuuteen liittyviä ongelmia. Ehdotamme skaalautuvaa monilähetysarkkitehtuuria suurille peiteverkoille. Ratkaisumme puuttuu adaptiivisen virhekorjauksen (Adaptive Hybrid Error Correction, AHEC) alioptimaalisuuteen monilähetystilanteissa. Luomme hierarkisen monivaiheisen monilähetyspuutopologian parantaaksemme AHECin suorituskykyä, sekä taataksemme monilähetysasiakkaiden palvelun laadun. Valitsimme evoluutiomaisen lähestymistavan, jolla on potentiaalia keventää multimediasovelluksien verkkoresurssivaatimuksia erottamalla virhekorjauksen omaksi verkkotunnuksekseen, sekä käyttämällä valikoivaa täydentävää tiedonlisäystä rinnakkaisverkoista vastaavan sisällön ollessa saatavilla. Sekä monikanava- että monilähetystiedonsiirto ovat selvästi osa internetin kehityssuuntaa. Tässä väitöskirjassa tutkimme monia ongelmia näiden tekniikoiden käyttöönottoon liittyen