HDMM: deploying client and network-based distributed mobility management

Mobile operators are now facing the challenges posed by a huge data demand from users, mainly due to the introduction of modern portable devices and the success of mobile applications. Moreover, users are now capable to connect from different access networks and establish several active sessions simultaneously, while being mobile. This triggered the introduction of a new paradigm: the distributed mobility management (DMM) which aims at flattening the network and distributing the entities in charge of managing users' mobility. In this article, we review existing DMM proposals and describe a hybrid solution which benefits from combining a network-based and a client-based approach. We analyze the signaling cost and the handover latency of our proposal, comparing them with their centralized alternatives. We also include validation and performance results from experiments conducted with a Linux-based prototype, which show that achievable enhancements depend on the underlying network topology. We argue that the proposed hybrid DMM solution provides additional flexibility to the mobile network operators, which can decide when and how to combine these two approaches.The research leading to these results has received funding from the European Community’s Seventh Framework Programme (FP7-ICT-2009-5) under Grant agreement n. 258053 (MEDIEVAL project) and from the Spanish Government, MICINN, under research grant TIN2010-20136-C0

Simultaneous multi-access in heterogeneous mobile networks

The exponential growth of the number of multihomed mobile devices is changing the way how we connect to the Internet. Unfortunately, it is not yet easily possible to a multihomed device to be simultaneously connected to the network through multiple links. This work enhances the network access of multihomed devices. This enhancement is achieved by using simultaneously all of the mobile devices interfaces, and by individually routing each data flow through the most adequate technology. The proposed solution is only deployed at the network core and it does not depend on the mobile devices, i.e., it’s transparent to the mobile devices. This work gives the necessary tools to reuse the already deployed technologies like WiFi or 3G/LTE. Moreover, it is also possible to extend the network by using femtocells which support multi access technologies. This work is also integrated with IEEE 802.21 standard to improve the handover mechanisms in the network. Additionally, we also propose an integration with a broker that can manage all the data flows individually. The proposed solution improves the quality of service of the users while not overloading the operator infrastructure. Evaluation results, obtained from the developed prototype, evidence that the overhead for using the proposed solution is very small when compared to the advantages.O crescimento exponencial do número de equipamentos móveis com múltiplas tecnologias de acesso à rede está a mudar a maneira como nos ligamos à Internet. Infelizmente, ainda não é possível usar simultaneamente todas as interfaces de rede de um equipamento móvel. Este trabalho melhora o acesso à rede a partir de dispositivos móveis com múltiplas interfaces de rede. Para alcançar esta melhoria todas as interfaces de rede dos dispositivos móveis podem ser usadas simultaneamente, e os fluxos de tráfego são encaminhados individualmente através da tecnologia mais conveniente. A solução proposta apenas é instalada na rede core, ou seja, é transparente para os equipamentos móveis. Este trabalho desenvolveu as ferramentas necessárias para reutilizar as tecnologias existentes que já estão disponíveis em larga escala, como o WiFi ou o 3G/LTE. É também possível usar femto-­células com suporte a múltiplas tecnologias de acesso para expandir mais rapidamente a rede. Este trabalho criou também uma integração com a norma IEEE 802.21 para melhorar os processos de handover. Adicionalmente propomos a integração com um broker externo para uma melhor gestão dos fluxos de tráfego. A solução proposta melhora a qualidade de serviço dos utilizadores sem sobrecarregar a infra-­estrutura do operador. Os resultados obtidos a partir dos testes realizados ao protótipo desenvolvido mostram que o impacto na performance ao usar esta solução é extremamente reduzido quando comparado com as suas vantagens

Distributed mobility management for a flat architecture in 5G mobile networks: solutions, analysis and experimental validation

In the last years, the commercial deployment of data services in mobile networks has been evolving quickly, providing enhanced radio access technologies and more efficient network architectures. Nowadays, mobile users enjoy broadband and ubiquitous wireless access through their portable devices, like smartphones and tablets, exploiting the connectivity offered by the modern 4G network. Nevertheless, the technological evolution keeps moving towards the development of next generation networks, or 5G, aiming at further improving the current system in order to cope with the huge data traffic growth foreseen in the future years. One of the possible research guidelines aims at innovating the mobile networks architecture by designing a flat system. Indeed, current systems are built upon a centralized and hierarchical structure, where multiple access networks are connected to a central core hosting crucial network functions, e.g., charging, control and maintenance, as well as mobility management, which is the main topic of this thesis. In such a central mobility management system, users’ traffic is aggregated at some key nodes in the core, called mobility anchors. Thus, an anchor can easily handle user’s mobility by redirecting traffic flows to his/her location, but i) it poses scalability issues, ii) it represents a single point of failure, and iii) the routing path is in general suboptimal. These problems can be overcome moving to a flat architecture, adopting a Distributed Mobility Management (DMM) system, where the centralized anchor is removed. This thesis develops within the DMM framework, presenting the design, analysis, implementation and experimental validation of several DMM protocols. In this work we describe original protocols for client-based and network-based mobility management, as well as a hybrid solution. We study analytically our solutions to evaluate their signaling cost, the packet delivery cost, and the latency introduced to handle a handover event. Finally, we assess the validity of some of our protocols with experiments run over a network prototype built in our lab implementing such solutions.El despliegue comercial de los servicios de datos en las redes móviles ha evolucionado rápidamente en los últimos años, proporcionando tecnologías de acceso radio más avanzadas y arquitecturas de red más eficientes. Los usuarios ya pueden disfrutar de los servicios de banda ancha desde sus dispositivos móviles, como smartphones y tablets, aprovechando la conectividad de las modernas redes 4G. Sin embargo, la evolución tecnológica sigue trazando su camino hasta el desarrollo de las redes de próxima generación, o 5G, en previsión del enorme aumento del tráfico de los años futuros. Una de las innovaciones bajo estudio aborda la arquitectura de las redes móviles, con el objetivo de diseñar un sistema plano. Efectivamente, el sistema actual se basa en una estructura centralizada y jerárquica, en la cual múltiples redes de acceso se conectan al núcleo central, dónde residen funciones cruciales para el control de la red y facturación, así como la gestión de la movilidad, que es el tema central de esta tesis. En un sistema con gestión centralizada de la movilidad, se agregan los flujos de tráfico en algunos nodos claves situados en el núcleo de la red, llamados anclas de movilidad. De este modo, un ancla puede fácilmente redirigir los flujos al lugar donde se halla el usuario, pero i) supone problemas de escalabilidad, ii) representa un punto único de fallo, y iii) el encaminamiento es en general sub-óptimo. Estos problemas se pueden resolver pasando a una arquitectura plana, cambiándose a un sistema de gestión distribuida de la movilidad (Distributed Mobility Management – DMM), donde no hay anclas centralizadas. Esta tesis se desarrolla dentro el marco propuesto por DMM, presentando el diseño, el análisis, la implementación y la validación experimental de varios protocolos de movilidad distribuida. Se describen soluciones basadas en el cliente y en la red, así como una solución híbrida. El funcionamiento de las soluciones ha sido estudiado analíticamente, para evaluar los costes de señalización, el coste del transporte de los paquetes y la latencia para gestionar el traspaso de los usuarios de una red a otra. Finalmente, la validez de los protocolos ha sido demostrada con experimentos sobre un prototipo donde se implementan algunas de las soluciones utilizando el equipamiento de nuestro laboratorio.Programa Oficial de Doctorado en Ingeniería TelemáticaPresidente: Arturo Azcorra Saloña.- Secretario: Ramón Agüero Calvo.- Vocal: Jouni Korhone