Proposal and analysis of integrated PTN architecture in the mobile backhaul to improve the QoS of HetNets

Los rápidos avances de las tecnologías de dispositivos móviles han implicado que la red de acceso debe evolucionar y desarrollar nuevas estrategias para satisfacer las necesidades de los usuarios. La red heterogénea (HetNet) permite una estrategia de implementación flexible y ofrece soluciones económicamente viables para mejorar la escalabilidad de red y cobertura en interiores. Este tema emergente ha captado la atención de la comunidad científica y la industria debido a la importancia de estas redes para satisfacer la demanda de servicios de datos. Para proporcionar esta demanda, deben satisfacerse diferentes parámetros de calidad de servicio (QoS). En este trabajo, presentamos un estudio sobre los últimos avances y los temas de investigación sobre movilidad en conjunción con protocolos de conmutación de etiquetas multiprotocolo (MPLS) de paquetes basado en redes de transporte (PTN) para proporcionar QoS en redes heterogéneas inalámbricas. Se presentan diversos protocolos de gestión móvil y su interacción con la red de retorno móvil yred básica por paquetes. Una nueva arquitectura denominada Proxy integrado Mobile MPLS-TP (MIP-TP) se expone también a reducir los costos y mejorar la señalización de la QoS en HetNets con altas tasas de movilidad.The rapid progress made in mobile device technologies has implied that the access network must evolute and develop new strategies to satisfy the requirements of the users. Heterogeneous network (HetNet) allows for a flexible deployment strategy and offers economically viable solutions to improve network scalability and indoor coverage. This emerging topic has caught the attention of the research community and the industry because of the importance of these networks to satisfy the demand of data services. To provide this demand, different parameters of quality of service (QoS) must be satisfied. In this paper, we present a study on recent advances and open research issues on Mobility Protocols in conjunction with Multi-Protocol Label Switching (MPLS)-based packet transport networks (PTN) to provide QoS in wireless heterogeneous networks. Various mobile management protocols and their interaction with the mobile backhaul and packet core network are briefly introduced. A new architecture called Integrated Proxy Mobile MPLS-TP (IPM-TP) is also outlined to reduce the signalling cost and improve the QoS in HetNets with high rates of mobility.Unión Europea. Fondos Europeos de Desarrollo Regional (FEDER). Proyecto SOE4/P3/E804peerReviewe

Optimal Power Allocation for Energy Efficient MIMO Relay Systems in 5G Wireless Communication

Wireless communication has undergone a significant growth to meet the unexpected demand of wireless data traffic over the past two decades. As manifested by the revolution of the third and fourth generations and long-term evolution advanced (LTE-A), engineers and researchers have been devoted to the development of the next-generation (5G) wireless solutions to meet the anticipated demand of 2020. To this end, cooperative relay communication has been introduced as an enabling technology to increase the throughput and extend the coverage of the broadband wireless networks. Decode-and-forward (DF) has been known as an effective cooperative relaying strategy for its outstanding features. On the other hand, merging massive multi-input-multi-output (MIMO) with cooperative DF relay is considered as a key technology for 5G wireless networks to improve the quality-of-service (QoS) in a cost-effective manner. The objective of this thesis is to establish and solve a power allocation optimization problem for energy efficient multi-pair DF relay systems integrated with massive MIMO. The first part of the thesis is focused on a constrained optimization problem to minimize the total transmit power for each transmission phase of the DF relay. Due to the non-convexity characteristic, the objective function is approximated as a convex function by means of complementary geometric programming (CGP) which is then solved by a sequence of geometric programming (GP). A lower bound of average SINR is also introduced by adopting the MMSE channel state information (CSI) to relax the constraint functions in the standard GP form. Finally, we proposed a homotopy or continuation method based algorithm to solve the optimization problem via popular CVX optimization toolbox. MATLAB simulations are conducted to validate the proposed algorithm. In the second part, another optimization problem is presented for the entire two-hop transmission of the DF relay to improve the global energy efficiency (GEE) under different channel conditions. Here, we estimate the channel by maximum likelihood (ML) criterion and investigate a closed-form expression of GEE. Further, GEE is approximated in a convex form by applying CGP due to the difficulty arising from the non-convexity and a lower bound of the average SINR expression is also derived to relax the constraint functions in the GP problem. Numerical results showing a detailed comparison of GEE under ML and MMSE channel estimation conditions and the performance improvement from the proposed algorithm are provided

Energy and Spectrum Efficient Transmission Techniques Under QoS Constraints Toward Green Heterogeneous Networks

This paper proposes a joint energy efficiency (EE) and spectrum efficiency (SE) tradeoff analysis as a multi-objective optimization problem (MOP) in the uplink of multi-user multi-carrier two-tier orthogonal frequency division multiplexing access heterogeneous networks subject to users' maximum transmission power and minimum rate constraints. The proposed MOP is modeled such that the network providers can dynamically tune the tradeoff parameters to switch between different communication scenarios with diverse design requirements. In order to find its Pareto optimal solution, the MOP is transformed, using a weighted sum method, into a single-objective optimization problem (SOP), which itself can further be transformed from a fractional form, by exploiting fractional programming, into a subtractive form. Since the formulated SOP is hard to solve due to the combinatorial channel allocation indicators, we reformulate the SOP into a better tractable problem by relaxing the combinatorial indicators using the idea of time-sharing. We then prove that this reformulated SOP is strictly quasi-concave with respect to the transmission power and the subcarrier allocation indicator. We then propose an iterative two-layer distributed framework to achieve an upper bound Pareto optimal solution of the original proposed MOP. The numerical simulations demonstrate the effectiveness of our proposed two-layer framework achieving an upper bound Pareto optimal solution, which is very close to an optimal solution, with fast convergence, lower and acceptable polynomial complexity, and balanced EE-SE tradeoff

Cognitive radio architecture for massive internet of things services with dynamic spectrum access

En esta investigación se propone una arquitectura cognitiva para servicios masivos de Internet de las cosas sobre Huecos Espectrales en Televisión. La propuesta seleccionó la banda de frecuencia de TVWS como la mejor para enfrentar el reto de escasez de espectro radioeléctrico para servicios masivos de IoT. La arquitectura provee la lista de canales disponibles a dispositivos IoT y tiene restricciones de Calidad de servicio (QoS). Definimos un mecanismo de acceso novedoso que se basa en políticas regulatorias al interactuar con TVWS Geolocation Base de datos (GLDB) a través del Protocolo de acceso a espacios en blanco (PAWS) para proporcionar la lista de canales disponibles para dispositivos IoT. Con respecto a restricciones de QoS, exploramos diferentes tipos de implementaciones y referencias áreas de cobertura considerando un modelo de probabilidad de pérdida de paquetes. Además, la investigación describe el proceso de optimización para obtener la máxima área de servicio mientras se mantiene una probabilidad de interrupción por debajo de un objetivo dado. Además, aplicamos un mecanismo de macro-diversidad para mejorar la probabilidad de pérdida de paquetes con respecto a nuestra propuesta y una topología con un solo dispositivo maestro. Podemos evidenciar que la probabilidad promedio de pérdida de paquetes es reducido en 26% cuando la carga es igual al 80% en nuestra propuesta.IMT AtlantiqueUniversidad Santo TomásCEA-IoT , Pontificia Universidad JaverianaThis research proposes a novel cognitive radio architecture for massive Internet of Things (IoT) services over TV White Spaces (TVWS). The proposal considers TVWS as suitable frequency bands for facing the limited spectrum problem for massive IoT services. The architecture provides the available list of channels to IoT devices, and its access mechanisms have Quality of Service (QoS) constrains. We define a novel access mechanism that is based on regulatory policies by interacting with TVWS Geolocation Database (GLDB) through the Protocol to Access White-Space (PAWS) for providing the available list of channels to IoT devices. Regarding QoS constraints, we explore different types of deployments and reference coverage areas considering a packet loss probability model. In addition, the research describes the optimization process to obtain the maximum service area while maintaining an outage probability below a given objective. Moreover, we applied a macro-diversity mechanism for improving the packet loss probability with respect to our proposal and one Master Device (MD) topology. We can evidence that the average packet loss probability is reduced in 26% when the load is equal to 80% in our proposal.Doctor en IngenieríaDoctoradohttps://orcid.org/0000-0002-9579-678Xhttps://scholar.google.es/citations?user=-VX8bMEAAAAJ&hl=eshttp://scienti.colciencias.gov.co:8081/cvlac/visualizador/generarCurriculoCv.do?cod_rh=000084496

Virtualisation des réseaux sans fil: stratégie optimisée de déploiement progressif

La virtualisation est un nouveau concept qui promet de répondre à la demande croissante en qualité de service (QoS) tout en réduisant d’une part les émissions de carbone et d’autres parts, les dépenses d’investissements de capital (CAPEX) ainsi que celles d’exploitation (OPEX). Dans ce contexte, plusieurs modèles de virtualisations des réseaux d’accès sans fil (WAV) ont été développés et sont utilises afin de trouver un équilibre entre la satisfaction des abonnés ainsi que le coût de déploiement des infrastructures réseau. Le choix d’un cadre de virtualisation est un grand défi puisque chaque modèle est caractérisé par un coût (CAPEX et OPEX) et une QoS bien spécifique. La virtualisation dans un contexte "green field" fournit un outil qui permet de donner une visibilité aux exploitants en prenant en considération leurs contraintes budgétaires ainsi que leurs exigences en termes de QoS. Toutefois, le déploiement de cette stratégie demeure inapplicable dans la pratique en raison de la migration brusque de LTE (Long Term Evolution) vers un réseau virtualisé. En outre, le processus de virtualisation nécessite un temps considérable afin de remplacer graduellement le réseau LTE sans avoir d’impact sur le bon fonctionnement du système. Ainsi, le déploiement progressif est une solution inévitable qui permettra aux exploitants et industriels d’avoir une vision pratique sur les différentes étapes du processus de virtualisation. L’objectif principal de ce projet de recherche est de proposer et de valider la meilleure stratégie de déploiement progressif (WAV) afin de permettre aux exploitants télécom d’avoir un outil optimisé et pratique pour le déploiement progressif. Dans ce mémoire, nous avons proposé deux stratégies de deployment progressif : pré-planifiée et optimisée. La première se base sur des algorithmes évolutionnaires tandis que la deuxième se base sur la théorie des graphes. Les résultats obtenus permettent de confirmer avec certitude que la stratégie optimisée de déploiement offre de meilleures performances. En effet, l’implémentation de ce nouvel outil nous permet non seulement de trouver la solution optimale de déploiement, mais aussi il permet de résoudre des problèmes d’optimisation multidimensionnelle de plus en plus hétérogènes (architectures de virtualisation, densités d’utilisateurs, HetNet, exploitants)

An efficient cluster-based service model for vehicular ad-hoc networks on motorways

Vehicular Ad-Hoc Networks (VANET) can, but not limited to provide users with useful traffic and environmental information services to improve travelling efficiency and road safety. The communications systems used in VANET include vehicle-to-vehicle communications (V2V) and vehicle-to-infrastructure communications (V2I). The transmission delay and the energy consumption cost for maintaining good-quality communications vary depending on the transmission distance and transmission power, especially on motorways where vehicles are moving at higher speeds. In addition, in modern transportation systems, electric vehicles are becoming more and more popular, which require a more efficient battery management, this also call for an efficient way of vehicular transmission. In this project, a cluster-based two-way data service model to provide real-time data services for vehicles on motorways is designed. The design promotes efficient cooperation between V2V and V2I, or namely V2X, with the objective of improving both service and energy performance for vehicular networks with traffic in the same direction. Clustering is an effective way of applying V2X in VANET systems, where the cluster head will take the main responsibility of exchanging data with Road Side Units (RSU) and other cluster members. The model includes local service data collection, data aggregation, and service data downloading. We use SUMO and OMNET++ to simulate the traffic scenarios and the network communications. Two different models (V2X and V2I) are compared to evaluate the performance of the proposed model under different flow speeds. From the results, we conclude that the cluster-based service model outperforms the non-clustered model in terms of service successful ratio, network throughput and energy consumption