Analytical modeling of HSUPA-enabled UMTS networks for capacity planning

In recent years, mobile communication networks have experienced significant evolution. The 3G mobile communication system, UMTS, employs WCDMA as the air interface standard, which leads to quite different mobile network planning and dimensioning processes compared with 2G systems. The UMTS system capacity is limited by the received interference at NodeBs due to the unique features of WCDMA, which is denoted as `soft capacity'. Consequently, the key challenge in UMTS radio network planning has been shifted from channel allocation in the channelized 2G systems to blocking and outage probabilities computation under the `cell breathing' effects which are due to the relationship between network coverage and capacity. The interference characterization, especially for the other-cell interference, is one of the most important components in 3G mobile networks planning. This monograph firstly investigates the system behavior in the operation of UMTS uplink, and develops the analytic techniques to model interference and system load as fully-characterized random variables, which can be directly applicable to the performance modeling of such networks. When the analysis progresses from single-cell scenario to multi-cell scenario, as the target SIR oriented power control mechanism is employed for maximum capacity, more sophisticated system operation, `feedback behavior', has emerged, as the interference levels at different cells depend on each other. Such behaviors are also captured into the constructed interference model by iterative and approximation approaches. The models are then extended to cater for the features of the newly introduced HSUPA, which provides enhanced dedicated channels for the packet switched data services such that much higher bandwidth can be achieved for best-effort elastic traffic, which allows network operators to cope with the coexistence of both circuit-switched and packet-switched traffic and guarantee the QoS requirements. During the derivation, we consider various propagation models, traffic models, resource allocation schemes for many possible scenarios, each of which may lead to different analytical models. All the suggested models are validated with either Monte-Carlo simulations or discrete event simulations, where excellent matches between results are always achieved. Furthermore, this monograph studies the optimization-based resource allocation strategies in the UMTS uplink with integrated QoS/best-effort traffic. Optimization techniques, both linear-programming based and non-linear-programming based, are used to determine how much resource should be assigned to each enhanced uplink user in the multi-cell environment where each NodeB possesses full knowledge of the whole network. The system performance under such resource allocation schemes are analyzed and compared via Monte-Carlo simulations, which verifies that the proposed framework may serve as a good estimation and optimal reference to study how systems perform for network operators

Analytical modeling of HSUPA-enabled UMTS networks for capacity planning

In recent years, mobile communication networks have experienced significant evolution. The 3G mobile communication system, UMTS, employs WCDMA as the air interface standard, which leads to quite different mobile network planning and dimensioning processes compared with 2G systems. The UMTS system capacity is limited by the received interference at NodeBs due to the unique features of WCDMA, which is denoted as `soft capacity'. Consequently, the key challenge in UMTS radio network planning has been shifted from channel allocation in the channelized 2G systems to blocking and outage probabilities computation under the `cell breathing' effects which are due to the relationship between network coverage and capacity. The interference characterization, especially for the other-cell interference, is one of the most important components in 3G mobile networks planning. This monograph firstly investigates the system behavior in the operation of UMTS uplink, and develops the analytic techniques to model interference and system load as fully-characterized random variables, which can be directly applicable to the performance modeling of such networks. When the analysis progresses from single-cell scenario to multi-cell scenario, as the target SIR oriented power control mechanism is employed for maximum capacity, more sophisticated system operation, `feedback behavior', has emerged, as the interference levels at different cells depend on each other. Such behaviors are also captured into the constructed interference model by iterative and approximation approaches. The models are then extended to cater for the features of the newly introduced HSUPA, which provides enhanced dedicated channels for the packet switched data services such that much higher bandwidth can be achieved for best-effort elastic traffic, which allows network operators to cope with the coexistence of both circuit-switched and packet-switched traffic and guarantee the QoS requirements. During the derivation, we consider various propagation models, traffic models, resource allocation schemes for many possible scenarios, each of which may lead to different analytical models. All the suggested models are validated with either Monte-Carlo simulations or discrete event simulations, where excellent matches between results are always achieved. Furthermore, this monograph studies the optimization-based resource allocation strategies in the UMTS uplink with integrated QoS/best-effort traffic. Optimization techniques, both linear-programming based and non-linear-programming based, are used to determine how much resource should be assigned to each enhanced uplink user in the multi-cell environment where each NodeB possesses full knowledge of the whole network. The system performance under such resource allocation schemes are analyzed and compared via Monte-Carlo simulations, which verifies that the proposed framework may serve as a good estimation and optimal reference to study how systems perform for network operators

LTE Optimization and Resource Management in Wireless Heterogeneous Networks

Mobile communication technology is evolving with a great pace. The development of the Long Term Evolution (LTE) mobile system by 3GPP is one of the milestones in this direction. This work highlights a few areas in the LTE radio access network where the proposed innovative mechanisms can substantially improve overall LTE system performance. In order to further extend the capacity of LTE networks, an integration with the non-3GPP networks (e.g., WLAN, WiMAX etc.) is also proposed in this work. Moreover, it is discussed how bandwidth resources should be managed in such heterogeneous networks. The work has purposed a comprehensive system architecture as an overlay of the 3GPP defined SAE architecture, effective resource management mechanisms as well as a Linear Programming based analytical solution for the optimal network resource allocation problem. In addition, alternative computationally efficient heuristic based algorithms have also been designed to achieve near-optimal performance

Recent Advances in Wireless Communications and Networks

This book focuses on the current hottest issues from the lowest layers to the upper layers of wireless communication networks and provides "real-time" research progress on these issues. The authors have made every effort to systematically organize the information on these topics to make it easily accessible to readers of any level. This book also maintains the balance between current research results and their theoretical support. In this book, a variety of novel techniques in wireless communications and networks are investigated. The authors attempt to present these topics in detail. Insightful and reader-friendly descriptions are presented to nourish readers of any level, from practicing and knowledgeable communication engineers to beginning or professional researchers. All interested readers can easily find noteworthy materials in much greater detail than in previous publications and in the references cited in these chapters

Cost based optimization for strategic mobile radio access network planning using metaheuristics

La evolución experimentada por las comunicaciones móviles a lo largo de las últimas décadas ha sido motivada por dos factores principales: el surgimiento de nuevas aplicaciones y necesidades por parte del usuario, así como los avances tecnológicos. Los servicios ofrecidos para términales móviles han evolucionado desde el clásico servicio de voz y mensajes cortos (SMS), a servicios más atractivos y por lo tanto con una rápida aceptación por parte de usuario final como, video telephony, video streaming, online gaming, and the internet broadband access (MBAS). Todos estos nuevos servicios se han convertido en una realidad gracias a los avances técnologicos, avances tales como nuevas técnicas de acceso al medio compartido, nuevos esquemas de codificiación y modulación de la información intercambiada, sistemas de transmisión y recepción basados en múltiples antenas (MIMO), etc. Un aspecto importante en esta evolución fue la liberación del sector a principios de los años 90, donde la función reguladora llevado a cabo por las autoridades regulatorias nacionales (NRA) se ha antojado fundamental. Uno de los principales problemas tratados por la NRA espcífica de cada nación es la determinación de los costes por servicios mayoristas, esto es los servicios entre operadores de servicios móvilles, entre los que cabe destacar el coste por terminación de llamada o de inteconexión. El servicio de interconexión hace posible la comunicación de usuarios de diferente operadores, así como el acceso a la totalidad de servicios, incluso a aquellos no prestados por un operador en concreto gracias al uso de una red perteneciente a otro operador, por parte de todos los usuarios. El objetivo principal de esta tesis es la minimización de los costes de inversión en equipamiento de red, lo cual repercute en el establecimiento de las tarifas de interconexión como se verá a lo largo de este trabajo. La consecución de dicho objetivo se divide en dos partes: en primer lugar, el desarrollo de un conjunto de algoritmos para el dimesionado óptimo de una red de acceso radio (RAN) para un sistema de comunicaciones móvilles. En segundo lugar, el diseño y aplicación de algoritmos de optimización para la distribución óptima de los servicios sobre el conjunto de tecnologías móviles existentes (OSDP). El modulo de diseño de red proporciona cuatro algoritmos diferenciados encargados del dimensionado y planificación de la red de acceso móvil. Estos algoritmos se aplican en un entorno multi-tecnología, considerando sistemas de segunda (2G), tercera (3G) y cuarta (4G) generación, multi-usuario, teniendo en cuenta diferentes perfiles de usuarios con su respectiva carga de tráfico, y multo-servicio, incluyendo voz, servicios de datos de baja velocidad (64-144 Kbps), y acceso a internet de banda ancha móvil. La segunda parte de la tesis se encarga de distribuir de una manera óptima el conjunto de servicios sobre las tecnologías a desplegar. El objetivo de esta parte es hacer un uso eficiente de las tecnologías existentes reduciendo los costes de inversión en equipamiento de red. Esto es posible gracias a las diferencias tecnológicas existente entre los diferentes sistemas móviles, que hacen que los sistemas de segunda generación sean adecuados para proporcionar el servicio de voz y mensajería corta, mientras que redes de tercera generación muestran un mejor rendimiento en la transmisión de servicios de datos. Por último, el servicio de banda ancha móvil es nativo de redes de última generadón, como High Speed Data Acces (HSPA) y 4G. Ambos módulos han sido aplicados a un extenso conjunto de experimentos para el desarrollo de análisis tecno-económicos tales como el estudio del rendimiento de las tecnologías de HSPA y 4G para la prestación del servicio de banda ancha móvil, así como el análisis de escenarios reales de despliegue para redes 4G que tendrán lugar a partir del próximo año coinicidiendo con la licitación de las frecuencias en la banda de 800 MHz. Así mismo, se ha llevado a cabo un estudio sobre el despliegue de redes de 4G en las bandas de 800 MHz, 1800 MHz y 2600 MHz, comparando los costes de inversión obtenidos tras la optimización. En todos los casos se ha demostrado la mejora, en términos de costes de inversión, obtenida tras la aplicación de ambos módulos, posibilitando una reducción en la determinación de los costes de provisión de servicios. Los estudios realizados en esta tesis se centran en la nación de España, sin embargo todos los algoritmos implementados son aplicables a cualquier otro país europeo, prueba de ello es que los algoritmos de diseño de red han sido utilizados en diversos proyectos de regulación

Cost based optimization for strategic mobile radio access network planning using metaheuristics

La evolución experimentada por las comunicaciones móviles a lo largo de las últimas décadas ha sido motivada por dos factores principales: el surgimiento de nuevas aplicaciones y necesidades por parte del usuario, así como los avances tecnológicos. Los servicios ofrecidos para términales móviles han evolucionado desde el clásico servicio de voz y mensajes cortos (SMS), a servicios más atractivos y por lo tanto con una rápida aceptación por parte de usuario final como, video telephony, video streaming, online gaming, and the internet broadband access (MBAS). Todos estos nuevos servicios se han convertido en una realidad gracias a los avances técnologicos, avances tales como nuevas técnicas de acceso al medio compartido, nuevos esquemas de codificiación y modulación de la información intercambiada, sistemas de transmisión y recepción basados en múltiples antenas (MIMO), etc. Un aspecto importante en esta evolución fue la liberación del sector a principios de los años 90, donde la función reguladora llevado a cabo por las autoridades regulatorias nacionales (NRA) se ha antojado fundamental. Uno de los principales problemas tratados por la NRA espcífica de cada nación es la determinación de los costes por servicios mayoristas, esto es los servicios entre operadores de servicios móvilles, entre los que cabe destacar el coste por terminación de llamada o de inteconexión. El servicio de interconexión hace posible la comunicación de usuarios de diferente operadores, así como el acceso a la totalidad de servicios, incluso a aquellos no prestados por un operador en concreto gracias al uso de una red perteneciente a otro operador, por parte de todos los usuarios. El objetivo principal de esta tesis es la minimización de los costes de inversión en equipamiento de red, lo cual repercute en el establecimiento de las tarifas de interconexión como se verá a lo largo de este trabajo. La consecución de dicho objetivo se divide en dos partes: en primer lugar, el desarrollo de un conjunto de algoritmos para el dimesionado óptimo de una red de acceso radio (RAN) para un sistema de comunicaciones móvilles. En segundo lugar, el diseño y aplicación de algoritmos de optimización para la distribución óptima de los servicios sobre el conjunto de tecnologías móviles existentes (OSDP). El modulo de diseño de red proporciona cuatro algoritmos diferenciados encargados del dimensionado y planificación de la red de acceso móvil. Estos algoritmos se aplican en un entorno multi-tecnología, considerando sistemas de segunda (2G), tercera (3G) y cuarta (4G) generación, multi-usuario, teniendo en cuenta diferentes perfiles de usuarios con su respectiva carga de tráfico, y multo-servicio, incluyendo voz, servicios de datos de baja velocidad (64-144 Kbps), y acceso a internet de banda ancha móvil. La segunda parte de la tesis se encarga de distribuir de una manera óptima el conjunto de servicios sobre las tecnologías a desplegar. El objetivo de esta parte es hacer un uso eficiente de las tecnologías existentes reduciendo los costes de inversión en equipamiento de red. Esto es posible gracias a las diferencias tecnológicas existente entre los diferentes sistemas móviles, que hacen que los sistemas de segunda generación sean adecuados para proporcionar el servicio de voz y mensajería corta, mientras que redes de tercera generación muestran un mejor rendimiento en la transmisión de servicios de datos. Por último, el servicio de banda ancha móvil es nativo de redes de última generadón, como High Speed Data Acces (HSPA) y 4G. Ambos módulos han sido aplicados a un extenso conjunto de experimentos para el desarrollo de análisis tecno-económicos tales como el estudio del rendimiento de las tecnologías de HSPA y 4G para la prestación del servicio de banda ancha móvil, así como el análisis de escenarios reales de despliegue para redes 4G que tendrán lugar a partir del próximo año coinicidiendo con la licitación de las frecuencias en la banda de 800 MHz. Así mismo, se ha llevado a cabo un estudio sobre el despliegue de redes de 4G en las bandas de 800 MHz, 1800 MHz y 2600 MHz, comparando los costes de inversión obtenidos tras la optimización. En todos los casos se ha demostrado la mejora, en términos de costes de inversión, obtenida tras la aplicación de ambos módulos, posibilitando una reducción en la determinación de los costes de provisión de servicios. Los estudios realizados en esta tesis se centran en la nación de España, sin embargo todos los algoritmos implementados son aplicables a cualquier otro país europeo, prueba de ello es que los algoritmos de diseño de red han sido utilizados en diversos proyectos de regulación

Efficient and Virtualized Scheduling for OFDM-Based High Mobility Wireless Communications Objects

Services providers (SPs) in the radio platform technology standard long term evolution (LTE) systems are enduring many challenges in order to accommodate the rapid expansion of mobile data usage. The modern technologies demonstrate new challenges to SPs, for example, reducing the cost of the capital and operating expenditures while supporting high data throughput per customer, extending battery life-per-charge of the cell phone devices, and supporting high mobility communications with fast and seamless handover (HO) networking architecture. In this thesis, a variety of optimized techniques aimed at providing innovative solutions for such challenges are explored. The thesis is divided into three parts. The first part outlines the benefits and challenges of deploying virtualized resource sharing concept. Wherein, SPs achieving a different schedulers policy are sharing evolved network B, allowing SPs to customize their efforts and provide service requirements; as a promising solution for reducing operational and capital expenditures, leading to potential energy savings, and supporting higher peak rates. The second part, formulates the optimized power allocation problem in a virtualized scheme in LTE uplink systems, aiming to extend the mobile devices’ battery utilization time per charge. While, the third part extrapolates a proposed hybrid-HO (HY-HO) technique, that can enhance the system performance in terms of latency and HO reliability at cell boundary for high mobility objects (up to 350 km/hr; wherein, HO will occur more frequent). The main contributions of this thesis are in designing optimal binary integer programmingbased and suboptimal heuristic (with complexity reduction) scheduling algorithms subject to exclusive and contiguous allocation, maximum transmission power, and rate constraints. Moreover, designing the HY-HO based on the combination of soft and hard HO was able to enhance the system performance in term of latency, interruption time and reliability during HO. The results prove that the proposed solutions effectively contribute in addressing the challenges caused by the demand for high data rates and power transmission in mobile networks especially in virtualized resources sharing scenarios that can support high data rates with improving quality of services (QoSs)

A survey of self organisation in future cellular networks

This article surveys the literature over the period of the last decade on the emerging field of self organisation as applied to wireless cellular communication networks. Self organisation has been extensively studied and applied in adhoc networks, wireless sensor networks and autonomic computer networks; however in the context of wireless cellular networks, this is the first attempt to put in perspective the various efforts in form of a tutorial/survey. We provide a comprehensive survey of the existing literature, projects and standards in self organising cellular networks. Additionally, we also aim to present a clear understanding of this active research area, identifying a clear taxonomy and guidelines for design of self organising mechanisms. We compare strength and weakness of existing solutions and highlight the key research areas for further development. This paper serves as a guide and a starting point for anyone willing to delve into research on self organisation in wireless cellular communication networks

Multi-hop relaying networks in TDD-CDMA systems

The communications phenomena at the end of the 20th century were the Internet and mobile telephony. Now, entering the new millennium, an effective combination of the two should become a similarly everyday experience. Current limitations include scarce, exorbitantly priced bandwidth and considerable power consumption at higher data rates. Relaying systems use several shorter communications links instead of the conventional point-to-point transmission. This can allow for a lower power requirement and, due to the shorter broadcast range, bandwidth re-use may be more efficiently exploited. Code division multiple access (CDMA) is emerging as one of the most common methods for multi user access. Combining CDMA with time division duplexing (TDD) provides a system that supports asymmetric communications and relaying cost-effectively. The capacity of CDMA may be reduced by interference from other users, hence it is important that the routing of relays is performed to minimise interference at receivers. This thesis analyses relaying within the context of TDD-CDMA systems. Such a system was included in the initial draft of the European 3G specifications as opportunity driven multiple access (ODMA). Results are presented which demonstrate that ODMA allows for a more flexible capacity coverage trade-off than non-relaying systems. An investigation into the interference characteristics of ODMA shows that most interference occurs close to the base station (BS). Hence it is possible that in-cell routing to avoid the BS may increase capacity. As a result, a novel hybrid network topology is presented. ODMA uses path loss as a metric for routing. This technique does not avoid interference, and hence ODMA shows no capacity increase with the hybrid network. Consequently, a novel interference based routing algorithm and admission control are developed. When at least half the network is engaged in in-cell transmission, the interference based system allows for a higher capacity than a conventional cellular system. In an attempt to reduce transmitted power, a novel congestion based routing algorithm is introduced. This system is shown to have lower power requirement than any other analysed system and, when more than 2 hops are allowed, the highest capacity. The allocation of time slots affects system performance through co-channel interference. To attempt to minimise this, a novel dynamic channel allocation (DCA) algorithm is developed based on the congestion routing algorithm. By combining the global minimisation of system congestion in both time slots and routing, the DCA further increases throughput. Implementing congestion routed relaying, especially with DCA, in any TDD-CDMA system with in-cell calls can show significant performance improvements over conventional cellular systems

The Four-C Framework for High Capacity Ultra-Low Latency in 5G Networks: A Review

Network latency will be a critical performance metric for the Fifth Generation (5G) networks expected to be fully rolled out in 2020 through the IMT-2020 project. The multi-user multiple-input multiple-output (MU-MIMO) technology is a key enabler for the 5G massive connectivity criterion, especially from the massive densification perspective. Naturally, it appears that 5G MU-MIMO will face a daunting task to achieve an end-to-end 1 ms ultra-low latency budget if traditional network set-ups criteria are strictly adhered to. Moreover, 5G latency will have added dimensions of scalability and flexibility compared to prior existing deployed technologies. The scalability dimension caters for meeting rapid demand as new applications evolve. While flexibility complements the scalability dimension by investigating novel non-stacked protocol architecture. The goal of this review paper is to deploy ultra-low latency reduction framework for 5G communications considering flexibility and scalability. The Four (4) C framework consisting of cost, complexity, cross-layer and computing is hereby analyzed and discussed. The Four (4) C framework discusses several emerging new technologies of software defined network (SDN), network function virtualization (NFV) and fog networking. This review paper will contribute significantly towards the future implementation of flexible and high capacity ultra-low latency 5G communications