User-centric power-friendly quality-based network selection strategy for heterogeneous wireless environments

The ‘Always Best Connected’ vision is built around the scenario of a mobile user seamlessly roaming within a multi-operator multi-technology multi-terminal multi-application multi-user environment supported by the next generation of wireless networks. In this heterogeneous environment, users equipped with multi-mode wireless mobile devices will access rich media services via one or more access networks. All these access networks may differ in terms of technology, coverage range, available bandwidth, operator, monetary cost, energy usage etc. In this context, there is a need for a smart network selection decision to be made, to choose the best available network option to cater for the user’s current application and requirements. The decision is a difficult one, especially given the number and dynamics of the possible input parameters. What parameters are used and how those parameters model the application requirements and user needs is important. Also, game theory approaches can be used to model and analyze the cooperative or competitive interaction between the rational decision makers involved, which are users, seeking to get good service quality at good value prices, and/or the network operators, trying to increase their revenue. This thesis presents the roadmap towards an ‘Always Best Connected’ environment. The proposed solution includes an Adapt-or-Handover solution which makes use of a Signal Strength-based Adaptive Multimedia Delivery mechanism (SAMMy) and a Power-Friendly Access Network Selection Strategy (PoFANS) in order to help the user in taking decisions, and to improve the energy efficiency at the end-user mobile device. A Reputation-based System is proposed, which models the user-network interaction as a repeated cooperative game following the repeated Prisoner’s Dilemma game from Game Theory. It combines reputation-based systems, game theory and a network selection mechanism in order to create a reputation-based heterogeneous environment. In this environment, the users keep track of their individual history with the visited networks. Every time, a user connects to a network the user-network interaction game is played. The outcome of the game is a network reputation factor which reflects the network’s previous behavior in assuring service guarantees to the user. The network reputation factor will impact the decision taken by the user next time, when he/she will have to decide whether to connect or not to that specific network. The performance of the proposed solutions was evaluated through in-depth analysis and both simulation-based and experimental-oriented testing. The results clearly show improved performance of the proposed solutions in comparison with other similar state-of-the-art solutions. An energy consumption study for a Google Nexus One streaming adaptive multimedia was performed, and a comprehensive survey on related Game Theory research are provided as part of the work

Enhancing cooperation in wireless networks using different concepts of game theory

PhDOptimizing radio resource within a network and across cooperating heterogeneous networks is the focus of this thesis. Cooperation in a multi-network environment is tackled by investigating network selection mechanisms. These play an important role in ensuring quality of service for users in a multi-network environment. Churning of mobile users from one service provider to another is already common when people change contracts and in a heterogeneous communication environment, where mobile users have freedom to choose the best wireless service-real time selection is expected to become common feature. This real time selection impacts both the technical and the economic aspects of wireless network operations. Next generation wireless networks will enable a dynamic environment whereby the nodes of the same or even different network operator can interact and cooperate to improve their performance. Cooperation has emerged as a novel communication paradigm that can yield tremendous performance gains from the physical layer all the way up to the application layer. Game theory and in particular coalitional game theory is a highly suited mathematical tool for modelling cooperation between wireless networks and is investigated in this thesis. In this thesis, the churning behaviour of wireless service users is modelled by using evolutionary game theory in the context of WLAN access points and WiMAX networks. This approach illustrates how to improve the user perceived QoS in heterogeneous networks using a two-layered optimization. The top layer views the problem of prediction of the network that would be chosen by a user where the criteria are offered bit rate, price, mobility support and reputation. At the second level, conditional on the strategies chosen by the users, the network provider hypothetically, reconfigures the network, subject to the network constraints of bandwidth and acceptable SNR and optimizes the network coverage to support users who would otherwise not be serviced adequately. This forms an iterative cycle until a solution that optimizes the user satisfaction subject to the adjustments that the network provider can make to mitigate the binding constraints, is found and applied to the real network. The evolutionary equilibrium, which is used to 3 compute the average number of users choosing each wireless service, is taken as the solution. This thesis also proposes a fair and practical cooperation framework in which the base stations belonging to the same network provider cooperate, to serve each other‘s customers. How this cooperation can potentially increase their aggregate payoffs through efficient utilization of resources is shown for the case of dynamic frequency allocation. This cooperation framework needs to intelligently determine the cooperating partner and provide a rational basis for sharing aggregate payoff between the cooperative partners for the stability of the coalition. The optimum cooperation strategy, which involves the allocations of the channels to mobile customers, can be obtained as solutions of linear programming optimizations

Planning and dynamic spectrum management in heterogeneous mobile networks with QoE optimization

The radio and network planning and optimisation are continuous processes that do not end after the network has been launched. To achieve the best trade-offs, especially between quality and costs, operators make use of several coverage and capacity enhancement methods. The research from this thesis proposes methods such as the implementation of cell zooming and Relay Stations (RSs) with dynamic sleep modes and Carrier Aggregation (CA) for coverage and capacity enhancements. Initially, a survey is presented on ubiquitous mesh networks implementation scenarios and an updated characterization of requirements for services and applications is proposed. The performance targets for the key parameters, delay, delay variation, information loss and throughput have been addressed for all types of services. Furthermore, with the increased competition, mobile operator’s success does not only depend on how good the offered Quality of Service (QoS) is, but also if it meets the end user’s expectations, i.e., Quality of Experience (QoE). In this context, a model for the mapping between QoS parameters and QoE has been proposed for multimedia traffic. The planning and optimization of fixed Worldwide Interoperability for Microwave Access (WiMAX) networks with RSs in conjunction with cell zooming has been addressed. The challenging case of a propagation measurement-based scenario in the hilly region of Covilhã has been considered. A cost/revenue function has been developed by taking into account the cost of building and maintaining the infrastructure with the use of RSs. This part of the work also investigates the energy efficiency and economic implications of the use of power saving modes for RSs in conjunction with cell zooming. Assuming that the RSs can be switched-off or zoomed out to zero in periods when the traffic exchange is low, such as nights and weekends, it has been shown that energy consumption may be reduced whereas cellular coverage and capacity, as well as economic performance may be improved. An integrated Common Radio Resource Management (iCRRM) entity is proposed that implements inter-band CA by performing scheduling between two Long Term Evolution – Advanced (LTE-A) Component Carriers (CCs). Considering the bandwidths available in Portugal, the 800 MHz and 2.6 GHz CCs have been considered whilst mobile video traffic is addressed. Through extensive simulations it has been found that the proposed multi-band schedulers overcome the capacity of LTE systems without CA. Result shown a clear improvement of the QoS, QoE and economic trade-off with CA

The mobile Internet report

Key ponts Material wealth creation / destruction should surpass earlier computing cycles. The mobile Internet cycle, the 5th cycle in 50 years, is just starting. Winners in each cycle often create more market capitalization than in the last. New winners emerge, some incumbents survive – or thrive – while many past winners falter. The mobile Internet is ramping faster than desktop Internet did, and we believe more users may connect to the Internet via mobile devices than desktop PCs within 5 years. Five IP-based products / services are growing / converging and providing the underpinnings for dramatic growth in mobile Internet usage – 3G adoption + social networking + video + VoIP + impressive mobile devices. Apple + Facebook platforms serving to raise the bar for how users connect / communicate – their respective ramps in user and developer engagement may be unprecedented. Decade-plus Internet usage / monetization ramps for mobile Internet in Japan plus desktop Internet in developed markets provide roadmaps for global ramp and monetization. Massive mobile data growth is driving transitions for carriers and equipment providers. Emerging markets have material potential for mobile Internet user growth. Low penetration of fixed-line telephone and already vibrant mobile value-added services mean that for many EM users and SMEs, the Internet will be mobile

Evaluation of channel switching threshold for MBMS in UMTS networks

In this project, thershold to switching from dedicated to shared/common channel for efficent delivery of MBMS serveces have been evaluated. It also been evaluated the coverage using multiple channer in function of the distribution of the user

Análise de desempenho e do comportamento do utilizador em redes 3G

Mestrado em Electrónica e TelecomunicaçõesA Qualidade de Serviço (QoS) é uma preocupação para os operadores, mas devido à evolução da rede para um enorme número de serviços com requisistos diferentes, garantir uma boa QoS não é exatcamente sinónimo de utilizadores satisfeitos. A percepção da qualidade de serviço por parte dos utilizadores (QoE) garante aos operadores uma visão do grau de satisfação do utilizador final. O objectivo de uma boa QoS deve ser promover uma melhor QoE nos utilizadores. A QoE permite aos operadores saberem de que forma é que as condições da rede satisfazem as expectativas dos seus utilizadores em termos de confiança, disponibilidade, escalabilidade, velocidade, desempenho e eficiência. O objectivo deste trabalho é o desenvolvimento de mecanismos que permitam aos operadores analisarem ao mesmo tempo o comportamento dos utilizadores e o estado da rede em termos de qualidade numa determinada região. Com este tipo de informação disponível os operadores podem adaptar os mecanismos de QoS da rede de modo a prencherem na totalidade as expectativas do utilizador final numa determinada região.The Quality of Service (QoS) is already a major concern for operators, but things are changing and, although in many cases better QoS results in better Quality of Experience (QoE), fulfilling the required performance parameters is not a synonym of satisfied users. QoE conditions can immediate response on the user satisfaction and thus the goal of QoS assurance should be to promote a better QoE. This will give the operator a deeper sense of the contribution of network’s performance to the overall level of customer satisfaction in terms of reliability, availability, scalability, speed, accuracy and efficiency. The main goal of this work is to provide operators with mechanisms for end user behaviour analysis and at the same instant detailed network status. With this information operators know the end users behaviour in a certain region, know in detail network performance metrics and can adapt QoS mechanisms to fulfil end users expectations

Adaptive, reliable, and accurate positioning model for location-based services

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.This thesis presents a new strategy in achieving highly reliable and accurate position solutions fulfilling the requirements of Location-Based Services (LBS) pedestrians’ applications. The new strategy is divided into two main parts. The first part integrates the available positioning technology within the surrounding LBS application context by introducing an adaptive LBS framework. The context can be described as a group of factors affecting the application behaviour; this includes environmental states, available resources and user preferences. The proposed adaptive framework consists of several stages, such as defining the contextual factors that have a direct effect on the positioning performance, identifying preliminary positioning performance requirements associated with different LBS application groups, and introducing an intelligent positioning services selection function. The second part of this work involves the design and development of a novel positioning model that is responsible for delivering highly reliable, accurate and precise position solutions to LBS users. This new model is based on the single frequency GPS Standard Positioning Service (SPS). Additionally, it is incorporated within the adaptive LBS framework while providing the position solutions, in which all identified contextual factors and application requirements are accounted. The positioning model operates over a client-server architecture including two main components, described as the Localisation Server (LS) and the Mobile Unit (MU). Hybrid functional approaches were developed at both components consisting of several processing procedures allowing the positioning model to operate in two position determination modes. Stand-alone mode is used if enough navigation information was available at the MU using its local positioning device (GPS/EGNOS receiver). Otherwise, server-based mode is utilised, in which the LS intervenes and starts providing the required position solutions. At the LS, multiple sources of GPS augmentation services were received using the Internet as the sole augmentation data transportation medium. The augmentation data was then processed and integrated for the purpose of guaranteeing the availability of valid and reliable information required for the provision of accurate and precise position solutions. Two main advanced position computation methods were developed at the LS, described as coordinate domain and raw domain. The positioning model was experimentally evaluated. According to the reported results, the LS through the developed position computation methods, was able to provide position samples with an accuracy of less than 2 meters, with high precision at 95% confidence level; this was achieved in urban, rural, and open space (clear satellite view) navigation environments. Additionally, the integrity of the position solutions was guaranteed in such environments during more than 90% of the navigation time, taking into consideration the identified integrity thresholds (Horizontal Alert Limits (HAL)=11 m). This positioning performance has outperformed the existing GPS/EGNOS service which was implemented at the MU in all scenarios and environments. In addition, utilising a simulation evaluation facility the developed positioning model performance was quantified with reference to a hybrid positioning service that will be offered by future Galileo Open Service (OS) along with GPS/EGNOS. Using the statistical t-test, it was concluded that there is no significant difference in terms of the position samples’ accuracy achieved from the developed positioning model and the hybrid system at a particular navigation environment described as rural area. The p-value was 0.08 and the level of significance used was 0.05. However, a significant difference in terms of the service integrity for the advantage of the hybrid system was experienced in all remaining scenarios and environments more especially the urban areas due to surrounding obstacles and conditions

4G Technology Features and Evolution towards IMT-Advanced

Kiinteiden- ja mobiilipalveluiden kysyntä kasvaa nopeasti ympäri maailmaa. Älykkäiden päätelaitteiden, kuten iPhone:n ja Nokia N900:n markkinoilletulo yhdistettynä näiden korkeaan markkinapenetraatioon ja korkealuokkaiseen käyttäjäkokemukseen lisäävät entisestään palveluiden kysyntää ja luovat tarpeen jatkuvalle innovoinnille langattomien teknologioiden alalla tavoitteena lisäkapasiteetin ja paremman palvelunlaadun tarjoaminen. Termi 4G (4th Generation) viittaa tuleviin neljännen sukupolven mobiileihin langattomiin palveluihin, jotka International Telecommunications Union:in Radiocommunication Sector (ITU-R) on määritellyt ja nimennyt International Mobile Telecommunications-Advanced (IMT-Advanced). Nämä ovat järjestelmiä, jotka pitävät sisällään IMT:n ne uudet ominaisuudet, jotka ylittävät IMT-2000:n vaatimukset. Long Term Evolution-Advanced (LTE-Advanced) ja IEEE 802.16m ovat IMT-A sertifiointiin lähetetyt kaksi pääasiallista kandidaattiteknologiaa. Tässä diplomityössä esitellään kolmannen sukupolven järjestelmien kehityspolku LTE:hen ja IEEE 802.16e-2005 asti. Lisäksi työssä esitetään LTE-Advanced:n ja IEEE 802.16m:n uudet vaatimukset ja ominaisuudet sekä vertaillaan näiden lähestymistapoja IMT-A vaatimusten täyttämiseksi. Lopuksi työssä luodaan katsaus LTE ja IEEE 802.16e-2005 (markkinointinimeltään Mobile WiMAX) -järjestelmien markkinatilanteeseen.The demand for affordable bandwidth in fixed and mobile services is growing rapidly around the world. The emergence of smart devices like the iPhone and Nokia N900, coupled with their high market penetration and superior user experience is behind this increased demand, inevitably driving the need for continued innovations in the wireless data technologies industry to provide more capacity and higher quality of service. The term "4G" meaning the 4th Generation of wireless technology describes mobile wireless services which have been defined by the ITU's Radiocommunication Sector (ITU-R) and titled International Mobile Telecommunications-Advanced (IMT-Advanced). These are mobile systems that include the new capabilities of IMT that go beyond those of IMT-2000. Long Term Evolution-Advanced (LTE-Advanced) and IEEE 802.16m are the two main candidate technologies submitted for IMT-Advanced certification. This thesis reviews the technology roadmap up to and including current 3G systems LTE from the 3rd Generation Partnership Project (3GPP) and IEEE 802.16e-2005 from the Institute of Electrical and Electronics Engineers (IEEE). Furthermore, new requirements and features for LTE-Advanced and IEEE 802.16m as well as a comparative approach towards IMT-Advanced certification are presented. Finally, the thesis concludes with a discussion on the market status and deployment strategies of LTE and IEEE 802.16e-2005, or Mobile WiMAX as it is being marketed