Self organisation for 4G/5G networks

Nowadays, the rapid growth of mobile communications is changing the world towards a fully connected society. Current 4G networks account for almost half of total mobile traffic, and in the forthcoming years, the overall mobile data traffic is expected to dramatically increase. To manage this increase in data traffic, operators adopt network topologies such as Heterogeneous Networks. Thus, operators can de­ ploy hundreds of small cells for each macro cell, allowing them to reduce coverage hales and/or lack of capacity. The advent of this technology is expected to tremendously increase the number of nodes in this new ecosystem, so that traditional network management activities based on, e.g., classic manual and field trial design approaches are just not be viable anymore. As a consequence, the academic J literature has dedicated a significant amount of effort to Self-Organising Network (SON) algorithms. These solutions aim to bring intelligence and autonomous adaptability into cellular networks, thereby reducing capital and operation expenditures (CAPEX/OPEX). Another aspect to take into account is that, these type of networks generate a large amount of data during their normal operation in the form of control, management and data measurements. This data is expected to increase in SG due to different aspects, such as densification, heterogeneity in layers and technologies, additional control and management complexity in Network Functions Virtualisation (NFV) and Software Defined Network (SDN), and the advent of the Internet of Things (loT), among others. In this context, operators face the challenge of de ­ signing efficient technologies, while introducing new services, reaching challenges in terms networks, which are self-aware, self-adaptive, and intelligent. This dissertation provides a contribution to the design, analysis, and evaluation of SON solutions to improve network opera tor performance, expenses, and users' experience, by making the network more self-adaptive and intelligent. It also provides a contribution to the design of a self-aware network planning tool, which allows to predict the Quality of Service (QoS) offered to end-users, based on data al ­ ready available in the network . The main thesis contributions are divided into two parts. The first part presents a novel functional architecture based on an automatic and self-organised Reinforcement Learning (RL) based approach to model SON functionalities, in which the main task is the self-coordination of different actions taken by different SON functions to be automatically executed in a self-organised realistic Long Term Evolution (LTE) network. The proposed approach introduces a new paradigm to deal with the conflicts genera ted by the concurrent execution of multiple SON functions, revealing that the proposed approach is general enough to modelali the SON functions and their derived conflicts. The second part of the thesis is dedicated to the problem of QoS prediction. In particular, we aim at finding patterns of knowledge from physical layer data acquired from heterogeneous LTE networks. We propose an approach that not only is able to verify the QoS level experienced by the users, through physical layer measurements of the UEs, but it is a lso able to predict it based on measurements collected at different time, and from different regions of the heterogeneous network. We propose then to make predictions independently of the physical location, in order to exploit the experience gained in other sectors of the network, to properly dimension and deploy heterogeneous nodes. In this context, we use Machine Learning (ML) as a tool to allow the network to learn from experience, improving performances, and big data analytics to drive the network from reactive to predictive.Hoy en día, el rápido crecimiento de las comunicaciones móviles está cambiando el mundo hacia una sociedad completamente conectada. Las redes 4G actuales representan casi la mitad del tráfico móvil total, y en los próximos años se espera que el tráfico total de los dispositivos móviles aumente drásticamente. Para gestionar este incremento de tráfico de datos, los operadores adoptan tecnologías de redes como las redes heterogéneas. De esta manera, los operadores pueden desplegar centena res de pequeñas celdas por cada macro celda, permitiendo reducir zonas sin cobertura y/o falta de capacidad. Con la introducción de esta tecnología, se espera que incremente de manera sustancia l el número de nodos en el nuevo ecosistema, de manera que las actividades de gestión de las redes tradicionales, basadas en, por ejemplo, el diseño manual, sean inviables. Como consecuencia, la literatura académica ha dedicado un esfuerzo significativo al diseño de algoritmos de redes auto-organizadas (SON). Estas soluciones tienen como objetivo introducir inteligencia y capacidad autónoma a las redes móviles, reduciendo la capacidad y costes operativos. Otro aspecto a tener en cuenta es que este tipo de redes generan una gran cantidad de datos durante su funcionamiento habitual, en forma de medidas de control y gestión de datos. Se espera que estos datos incrementen con la tecnología SG, debido a diferentes aspectos como los son la densificación de redes heterogéneas, la complejidad adicional en el control y la gestión de la virtualización de las funciones de redes (NFV) y las redes definidas por software (SON), así como la llegada del internet de las cosas (loT), entre otros. En este contexto, los operadores se enfrentan al reto de diseñar tecnologías eficientes, mientras introducen nuevos servicios, consiguiendo objetivos en términos de satisfacción del cliente, en donde el objetivo global del operador es la construcción de redes auto-conscientes, auto-adaptables e inteligentes. Esta tesis ofrece una contribución al diseño y evaluación de soluciones SON para mejorar el rendimiento de las redes, los costes y la experiencia de los usuarios, consiguiendo que la red sea auto-adaptable e inteligente. Así mismo, proporciona una contribución al diseño de una herramienta de planificación de red auto-consciente, que permita predecir la calidad de servicio brindada a los usuarios finales, basada en la explotación de datos disponibles en la red.Avui en dia, el ràpid creixement de les comunicacions mòbils està canviant el món cap a una societat completament connectada. Les xarxes 4G actuals representen casi la m trànsit mòbil total, i en els propers anys s’espera que el trànsit total de dades mòbils augmenti dràsticament. Per gestionar aquest increment de trànsit de dades, els operadors adopten topologies de xarxa com ara les xarxes heterogènies (HetNets). D’aquesta manera, els operadors poden desplegar centenars de cel·les petites per a cada cella macro, permetent reduir forats en la cobertura i/o la manca de capacitat. Amb l’arribada d’aquesta tecnologia, s’espera que incrementi enormement el nombre de nodes en el nou ecosistema, de manera que les activitats de gestió de xarxa tradicionals, basades en, per exemple, el disseny manual i els assaigs de camp esdevenen simplement inviables. Com a conseqüència, la literatura acadèmica ha dedicat una quantitat significativa d’esforç als algorismes de xarxa auto organitzada (SON). Aquestes solucions tenen com a objectiu portar la intel·ligència i capacitat d’adaptació autònoma a les xarxes mòbils, reduint el capital i les despeses operatives (CAPES/OPEX). Un altre aspecte a tenir en compte és que aquest tipus de xarxes generen una gran quantitat de dades durant el seu funcionament habitual, en forma de mesuraments de control, gestió i dades. S’espera que aquestes dades incrementin amb la tecnologia 5G, degut a diferents aspectes com ara la densificació, l’heterogeneïtat en capes i tecnologies, la complexitat addicional en el control i la gestió de la virtualització de les funcions de xarxa (NFV) i xarxes definides per software (SDN), i l’adveniment de la internet de les coses (IoT), entre d’altres. En aquest context, els operadors s’enfronten al repte de dissenyar tecnologies eficients, mentre introdueixen nous serveis, aconseguint objectius en termes de satisfacció del client, i on l’objectiu global d’un operador és la construcció de xarxes que són autoconscients, auto-adaptables i intel·ligents. Aquesta tesis ofereix una contribució al disseny, l’anàlisi i l’avaluació de les solucions SON per millorar el rendiment de l’operador de xarxa, les xi despeses i l’experiència dels usuaris, fent que la xarxa sigui més auto-adaptable i intel·ligent. També proporciona una contribució al disseny d’una eina de planificació de xarxa autoconscient, el que permet predir la qualitat de servei (QoS) oferta als usuaris finals, basada en dades ja disponibles a la xarxa. Les contribucions principals d’aquesta tesis es divideixen en dues parts. La primera part presenta una nova arquitectura funcional basada en un aprenentatge per reforç (RL) automàtic i auto-organitzat, enfocat en modelar funcionalitats SON, on la tasca principal és l’auto-coordinació de les diferents accions dutes a terme perles diferents funcions SON a ser executades de forma automàtica en una xarxa Long Term Evolution (LTE) auto-organitzada. L’enfocament proposat introdueix un nou paradigma perfer front als conflictes generats per l’execució simultània de múltiples funcions SON, revelant que l’enfocament proposat és prou general per modelar totes les funcions SON i els seus conflictes derivats. La segona part de la tesis està dedicada al problema de la predicció de la qualitat de servei. En particular, el nostre objectiu és trobar patrons de coneixement a partir de dades de la capa física adquirides de xarxes LTE heterogènies. Proposem un enfocament que no només és capaç de verificar el nivell de QoS experimentat pels usuaris, a través de mesuraments de la capa física dels UEs, sinó que també és capaç de predir-ho basant-se en mesuraments adquirits en diferents instants, i de diferents regions de la xarxa heterogènia. Proposem per tant fer prediccions amb independència de la ubicació física, aprofitant l’experiència adquirida en altres sectors de la xarxa, per dimensionar i desplegar nodes heterogenis correctament. En aquest context, utilitzem l’aprenentatge automàtic (ML) com a eina per permetre que la xarxa aprengui de l’experiència, millorant el rendiment, i l’anàlisi de grans volums de dades per a conduir la xarxa de reactiva a predictiva. Durant l’elaboració d’aquesta tesis, s’han extret dues conclusions principals clau. En primer lloc, destaquem la importància de dissenyar algorismes SON eficients per fer front eficaçment a diversos reptes, com ara la ubicació més adequada de funcions SON i algorismes per resoldre adequadament el problema d’implementació distribuïda o centralitzada, o la solució de conflictes entre funcions SON executades a diferents nodes o xarxes. En segon lloc, en termes d’eines de planificació de xarxes, es poden trobar diferents eines cobrint una àmplia gamma de sistemes i aplicacions orientades a la indústria, així com per a fins d’investigació. En aquest context, les solucions investigades són sotmeses contínuament a canvis importants, on un del principals impulsors és presentar solucions més rentable

A comprehensive survey on radio resource management in 5G HetNets: current solutions, future trends and open issues

The 5G network technologies are intended to accommodate innovative services with a large influx of data traffic with lower energy consumption and increased quality of service and user quality of experience levels. In order to meet 5G expectations, heterogeneous networks (HetNets) have been introduced. They involve deployment of additional low power nodes within the coverage area of conventional high power nodes and their placement closer to user underlay HetNets. Due to the increased density of small-cell networks and radio access technologies, radio resource management (RRM) for potential 5G HetNets has emerged as a critical avenue. It plays a pivotal role in enhancing spectrum utilization, load balancing, and network energy efficiency. In this paper, we summarize the key challenges i.e., cross-tier interference, co-tier interference, and user association-resource-power allocation (UA-RA-PA) emerging in 5G HetNets and highlight their significance. In addition, we present a comprehensive survey of RRM schemes based on interference management (IM), UA-RA-PA and combined approaches (UA-RA-PA + IM). We introduce a taxonomy for individual (IM, UA-RA-PA) and combined approaches as a framework for systematically studying the existing schemes. These schemes are also qualitatively analyzed and compared to each other. Finally, challenges and opportunities for RRM in 5G are outlined, and design guidelines along with possible solutions for advanced mechanisms are presented

Resource Management and Backhaul Routing in Millimeter-Wave IAB Networks Using Deep Reinforcement Learning

Thesis (PhD (Electronic Engineering))--University of Pretoria, 2023..The increased densification of wireless networks has led to the development of integrated access and backhaul (IAB) networks. In this thesis, deep reinforcement learning was applied to solve resource management and backhaul routing problems in millimeter-wave IAB networks. In the research work, a resource management solution that aims to avoid congestion for access users in an IAB network was proposed and implemented. The proposed solution applies deep reinforcement learning to learn an optimized policy that aims to achieve effective resource allocation whilst minimizing congestion and satisfying the user requirements. In addition, a deep reinforcement learning-based backhaul adaptation strategy that leverages a recursive discrete choice model was implemented in simulation. Simulation results where the proposed algorithms were compared with two baseline methods showed that the proposed scheme provides better throughput and delay performance.Sentech Chair in Broadband Wireless Multimedia Communications.Electrical, Electronic and Computer EngineeringPhD (Electronic Engineering)Unrestricte

Neural network design for intelligent mobile network optimisation

This thesis was submitted for the award of Doctor of Philosophy and was awarded by Brunel University LondonThe mobile networks users’ demands for data services are increasing exponentially, this is due to two main factors: the first is the evolution of smart phones and their application, and the second is the emerging new technologies for internet of things, smart cities…etc, which keeps pumping more data into the network; ‘though most of the data routed in the current mobile network is non-live data’. This increasing of demands arise the necessity for the mobile network operators to keep improving their network to satisfy it, this improvement takes place via adding hardware or increasing the resources or a combination of both. The radio resources are strictly limited due to spectrum licensing and availability, therefore efficient spectrum utilization is a major goal to be achieved for both network operators and developers. Simultaneous and multiple channel access,and adding more cells to the network are ways used to increase the data exchanged between the network nodes. The current 4G mobile system is based on the Orthogonal Frequency Division Multiple Access (OFDMA) for accessing the medium and the intercell interference degrades the link quality at the cell edge, with the introduction of heterogeneity concept to the LTE in Release 10 of the 3GPP the handover process became even more complex. To mitigate the intercell interference at the cell edge, coordinated multipoint and carrier aggregation techniques are utilized for dual connectivity. This work is focused on designing and proposing enhancing features to improve network performance and sustainability, these features comprises of distributing small cells for data only transmission, handover schemes performance evaluation at cell edge with dual connectivity, and Artificial Intelligence technology for balancing and prediction. In the proposed model design the data and controls of the Small eNodeB (SeNodeB) are processed at the network edge using a Mobile Edge Computing (MEC) server and the SeNodeBs are used to boost services provided to the users, also the concept of caching data has been investigated, the caching units where implemented in different network levels. The proposed system and resource management are simulated using the OPNET modeller and evaluated through multiple scenarios with and without full load, the UE is reconfigured to accommodate dual connectivity and have two separate connections for uplink and downlink, while maintaining connection to the Macro cell via uplink, the downlink is dedicated for small cells when content is requested from the cache. The results clearly show that the proposed system can decrease the latency while the total throughput delivered by the network has highly improved when SeNodeBs are deployed in the system, rising throughput will incur the rise of overall capacity which leads to better services being provided to the users or more users to join and benefit from the network. Handover improvement is also considered in this work, with the help of two Artificial Intelligence (AI) entities better handover performance are achieved. Balanced load over the SeNodeBs results in less frequent handover, the proposed load balancer is based on artificial neural network clustering model with self-organizing map as a hidden layer, it’s trained to forecast the network condition and learn to reduce the number of handovers especially for the UEs at the cell edge by performing only necessary ones, and avoid handovers to the Macro cell for the downlink direction. The examined handovers concern the downlinks when routing non live video stored at the small cell’s cache, and a reduction in the frequent handovers was achieved when running the balancer. Keep revolving in the handover orbit, another way to preserve and utilize network resources is by predicting the handovers before they occur, and allocate the required data in the target SeNodeB, the predictor entity in the proposed system architecture combines the features of Radial Basis Function Neural Network and neural network time series tool to create and update prediction list from the system’s collected data and learn to predict the next SeNodeB to associate with. The prediction entity is simulated using MATLAB, and the results shows that the system was able to deliver up to 92% correct predictions for handovers which led to overall throughput improvement of 75%

Packet Scheduling Algorithms in LTE/LTE-A cellular Networks: Multi-agent Q-learning Approach

Spectrum utilization is vital for mobile operators. It ensures an efficient use of spectrum bands, especially when obtaining their license is highly expensive. Long Term Evolution (LTE), and LTE-Advanced (LTE-A) spectrum bands license were auctioned by the Federal Communication Commission (FCC) to mobile operators with hundreds of millions of dollars. In the first part of this dissertation, we study, analyze, and compare the QoS performance of QoS-aware/Channel-aware packet scheduling algorithms while using CA over LTE, and LTE-A heterogeneous cellular networks. This included a detailed study of the LTE/LTE-A cellular network and its features, and the modification of an open source LTE simulator in order to perform these QoS performance tests. In the second part of this dissertation, we aim to solve spectrum underutilization by proposing, implementing, and testing two novel multi-agent Q-learning-based packet scheduling algorithms for LTE cellular network. The Collaborative Competitive scheduling algorithm, and the Competitive Competitive scheduling algorithm. These algorithms schedule licensed users over the available radio resources and un-licensed users over spectrum holes. In conclusion, our results show that the spectrum band could be utilized by deploying efficient packet scheduling algorithms for licensed users, and can be further utilized by allowing unlicensed users to be scheduled on spectrum holes whenever they occur

A Vision and Framework for the High Altitude Platform Station (HAPS) Networks of the Future

A High Altitude Platform Station (HAPS) is a network node that operates in the stratosphere at an of altitude around 20 km and is instrumental for providing communication services. Precipitated by technological innovations in the areas of autonomous avionics, array antennas, solar panel efficiency levels, and battery energy densities, and fueled by flourishing industry ecosystems, the HAPS has emerged as an indispensable component of next-generations of wireless networks. In this article, we provide a vision and framework for the HAPS networks of the future supported by a comprehensive and state-of-the-art literature review. We highlight the unrealized potential of HAPS systems and elaborate on their unique ability to serve metropolitan areas. The latest advancements and promising technologies in the HAPS energy and payload systems are discussed. The integration of the emerging Reconfigurable Smart Surface (RSS) technology in the communications payload of HAPS systems for providing a cost-effective deployment is proposed. A detailed overview of the radio resource management in HAPS systems is presented along with synergistic physical layer techniques, including Faster-Than-Nyquist (FTN) signaling. Numerous aspects of handoff management in HAPS systems are described. The notable contributions of Artificial Intelligence (AI) in HAPS, including machine learning in the design, topology management, handoff, and resource allocation aspects are emphasized. The extensive overview of the literature we provide is crucial for substantiating our vision that depicts the expected deployment opportunities and challenges in the next 10 years (next-generation networks), as well as in the subsequent 10 years (next-next-generation networks).Comment: To appear in IEEE Communications Surveys & Tutorial

QoS constrained cellular ad hoc augmented networks

In this dissertation, based on different design criteria, three novel quality of service (QoS) constrained cellular ad hoc augmented network (CAHAN) architectures are proposed for next generation wireless networks. The CAHAN architectures have a hybrid architecture, in which each MT of CDMA cellular networks has ad hoc communication capability. The CAHAN architectures are an evolutionary approach to conventional cellular networks. The proposed architectures have good system scalability and high system reliability. The first proposed architecture is the QoS constrained minimum-power cellular ad hoc augmented network architecture (QCMP CAHAN). The QCMP CAHAN can find the optimal minimum-power routes under the QoS constraints (bandwidth, packet-delay, or packet-error-rate constraint). The total energy consumed by the MTs is lower in the case of QCMP CAHAN than in the case of pure cellular networks. As the ad hoc communication range of each MT increases, the total transmitted power in QCMP CAHAN decreases. However, due to the increased number of hops involved in information delivery between the source and the destination, the end-to-end delay increases. The maximum end-to-end delay will be limited to a specified tolerable value for different services. An MT in QCMP CAHAN will not relay any messages when its ad hoc communication range is zero, and if this is the case for all MTs, then QCMP CAHAN reduces to the traditional cellular network. A QoS constrained network lifetime extension cellular ad hoc augmented network architecture (QCLE CAHAN) is proposed to achieve the maximum network lifetime under the QoS constraints. The network lifetime is higher in the case of QCLE CAHAN than in the case of pure cellular networks or QCMP CAHAN. In QCLE CAHAN, a novel QoS-constrained network lifetime extension routing algorithm will dynamically select suitable ad-hoc-switch-to-cellular points (ASCPs) according to the MT remaining battery energy such that the selection will balance all the MT battery energy and maximizes the network lifetime. As the number of ASCPs in an ad hoc subnet decreases, the network lifetime will be extended. Maximum network lifetime can be increased until the end-to-end QoS in QCLE CAHAN reaches its maximum tolerable value. Geocasting is the mechanism to multicast messages to the MTs whose locations lie within a given geographic area (target area). Geolocation-aware CAHAN (GA CAHAN) architecture is proposed to improve total transmitted power expended for geocast services in cellular networks. By using GA CAHAN for geocasting, saving in total transmitted energy can be achieved as compared to the case of pure cellular networks. When the size of geocast target area is large, GA CAHAN can save larger transmitted energy

Optimization of Mobility Parameters using Fuzzy Logic and Reinforcement Learning in Self-Organizing Networks

In this thesis, several optimization techniques for next-generation wireless networks are proposed to solve different problems in the field of Self-Organizing Networks and heterogeneous networks. The common basis of these problems is that network parameters are automatically tuned to deal with the specific problem. As the set of network parameters is extremely large, this work mainly focuses on parameters involved in mobility management. In addition, the proposed self-tuning schemes are based on Fuzzy Logic Controllers (FLC), whose potential lies in the capability to express the knowledge in a similar way to the human perception and reasoning. In addition, in those cases in which a mathematical approach has been required to optimize the behavior of the FLC, the selected solution has been Reinforcement Learning, since this methodology is especially appropriate for learning from interaction, which becomes essential in complex systems such as wireless networks. Taking this into account, firstly, a new Mobility Load Balancing (MLB) scheme is proposed to solve persistent congestion problems in next-generation wireless networks, in particular, due to an uneven spatial traffic distribution, which typically leads to an inefficient usage of resources. A key feature of the proposed algorithm is that not only the parameters are optimized, but also the parameter tuning strategy. Secondly, a novel MLB algorithm for enterprise femtocells scenarios is proposed. Such scenarios are characterized by the lack of a thorough deployment of these low-cost nodes, meaning that a more efficient use of radio resources can be achieved by applying effective MLB schemes. As in the previous problem, the optimization of the self-tuning process is also studied in this case. Thirdly, a new self-tuning algorithm for Mobility Robustness Optimization (MRO) is proposed. This study includes the impact of context factors such as the system load and user speed, as well as a proposal for coordination between the designed MLB and MRO functions. Fourthly, a novel self-tuning algorithm for Traffic Steering (TS) in heterogeneous networks is proposed. The main features of the proposed algorithm are the flexibility to support different operator policies and the adaptation capability to network variations. Finally, with the aim of validating the proposed techniques, a dynamic system-level simulator for Long-Term Evolution (LTE) networks has been designed