Optimizing Flow Thinning Protection in Multicommodity Networks with Variable Link Capacity

International audienceFlow thinning (FT) is a concept of a traffic routing and protection strategy applicable to communication networks withvariable capacity of links. In such networks, the links do not attain their nominal (maximum) capacity simultaneously, so in atypical network state only some links are fully available whereas on each of the remaining links only a fraction of itsmaximum capacity is usable. Every end-to-end traffic demand is assigned a set of logical tunnels whose total capacity isdedicated to carry the demand’s traffic. The nominal (i.e., maximum) capacity of the tunnels, supported by the nominal(maximum) link capacity, is subject to state-dependent thinning to account for variable capacity of the links fluctuating belowthe maximum. Accordingly, the capacity available on the tunnels is also fluctuating below their nominal levels and hence theinstantaneous traffic sent between the demand’s end nodes must accommodate to the current total capacity available onits dedicated tunnels. The related multi-commodity flow optimization problem is NP-hard and its noncompact linearprogramming formulation requires path generation. For that, we formulate an integer programming pricing problem, atthe same time showing the cases when the pricing is polynomial. We also consider an important variant of FT, affinethinning, that may lead to practical FT implementations. We present a numerical study illustrating traffic efficiency of FT andcomputational efficiency of its optimization models. Our considerations are relevant, among others, for wireless meshnetworks utilizing multiprotocol label switching tunnels

Efficient radio resource management in next generation wireless networks

The current decade has witnessed a phenomenal growth in mobile wireless communication networks and subscribers. In 2015, mobile wireless devices and connections were reported to have grown to about 7.9 billion, exceeding human population. The explosive growth in mobile wireless communication network subscribers has created a huge demand for wireless network capacity, ubiquitous wireless network coverage, and enhanced Quality of Service (QoS). These demands have led to several challenging problems for wireless communication networks operators and designers. The Next Generation Wireless Networks (NGWNs) will support high mobility communications, such as communication in high-speed rails. Mobile users in such high mobility environment demand reliable QoS, however, such users are plagued with a poor signal-tonoise ratio, due to the high vehicular penetration loss, increased transmission outage and handover information overhead, leading to poor QoS provisioning for the networks' mobile users. Providing a reliable QoS for high mobility users remains one of the unique challenges for NGWNs. The increased wireless network capacity and coverage of NGWNs means that mobile communication users at the cell-edge should have enhanced network performance. However, due to path loss (path attenuation), interference, and radio background noise, mobile communication users at the cell-edge can experience relatively poor transmission channel qualities and subsequently forced to transmit at a low bit transmission rate, even when the wireless communication networks can support high bit transmission rate. Furthermore, the NGWNs are envisioned to be Heterogeneous Wireless Networks (HWNs). The NGWNs are going to be the integration platform of diverse homogeneous wireless communication networks for a convergent wireless communication network. The HWNs support single and multiple calls (group calls), simultaneously. Decision making is an integral core of radio resource management. One crucial decision making in HWNs is network selection. Network selection addresses the problem of how to select the best available access network for a given network user connection. For the integrated platform of HWNs to be truly seamless and efficient, a robust and stable wireless access network selection algorithm is needed. To meet these challenges for the different mobile wireless communication network users, the NGWNs will have to provide a great leap in wireless network capacity, coverage, QoS, and radio resource utilization. Moving wireless communication networks (mobile hotspots) have been proposed as a solution to providing reliable QoS to high mobility users. In this thesis, an Adaptive Thinning Mobility Aware (ATMA) Call Admission Control (CAC) algorithm for improving the QoS and radio resource utilization of the mobile hotspot networks, which are of critical importance for communicating nodes in moving wireless networks is proposed. The performance of proposed ATMA CAC scheme is investigated and compare it with the traditional CAC scheme. The ATMA scheme exploits the mobility events in the highspeed mobility communication environment and the calls (new and handoff calls) generation pattern to enhance the QoS (new call blocking and handoff call dropping probabilities) of the mobile users. The numbers of new and handoff calls in wireless communication networks are dynamic random processes that can be effectively modeled by the Continuous Furthermore, the NGWNs are envisioned to be Heterogeneous Wireless Networks (HWNs). The NGWNs are going to be the integration platform of diverse homogeneous wireless communication networks for a convergent wireless communication network. The HWNs support single and multiple calls (group calls), simultaneously. Decision making is an integral core of radio resource management. One crucial decision making in HWNs is network selection. Network selection addresses the problem of how to select the best available access network for a given network user connection. For the integrated platform of HWNs to be truly seamless and efficient, a robust and stable wireless access network selection algorithm is needed. To meet these challenges for the different mobile wireless communication network users, the NGWNs will have to provide a great leap in wireless network capacity, coverage, QoS, and radio resource utilization. Moving wireless communication networks (mobile hotspots) have been proposed as a solution to providing reliable QoS to high mobility users. In this thesis, an Adaptive Thinning Mobility Aware (ATMA) Call Admission Control (CAC) algorithm for improving the QoS and radio resource utilization of the mobile hotspot networks, which are of critical importance for communicating nodes in moving wireless networks is proposed

Resource allocation in networks from a connection-level perspective (Asignación de recursos en redes desde la perspectiva de las conexiones)

En esta tesis, se analizan varios problemas de asignación recursos que surgen en el estudio de los sistemas de telecomunicaciones. En particular, nos centramos en las redes de datos, de los cuales el ejemplo más importante es la Internet global. En este tipo de redes, el recurso escaso que debe ser asignado es la cantidad de ancho de banda de cada conexión curso. Esta asignación realiza en tiempo real por los protocolos subyacentes, que técniamente se encuentran divididos en varios niveles o capas. Desde este punto de vista, la red puede ser pensada como un sistema de control a gran escala, donde cada entidad debe seguir un conjunto dado de leyes de control, a fin de encontrar una asignación adecuada de recursos. Desde el influyente trabajo de Kelly et. al., este problema se ha expresado en términos económicos, dando lugar a la teoría conocida como Network Utility Maximization (maximización de utilidad en redes). Este marco ha demostrado ser una herramienta valiosa para analizar los mecanismos existentes y diseño de protocolos nuevos que mejoran el comportamiento de la red. Proporciona además un vínculo crucial entre el tradicional análisis por capas de los protocolos de red y las técnicas de optimización convexa, dando lugar a lo que se denomina análisis multi-capa de las redes. En este trabajo nos centramos en el análisis de la red desde una perspectiva a nivel de conexiones. En particular, se estudia el desempeño de eficiencia y justicia en la escala de conexiones de varios modelos de asignación de recursos en la red. Este estudio se realiza en varios escenarios: tanto single-path como multi-path (redes con múltiples caminos) así como escenarios cableados e inalámbricos. Se analizan en detalle dos problemas importantes: por un lado, la asignación de los recursos realizada por los protocolos de control de congestión cuando se permiten varias conexiones por usuario. Se identifican algunos problemas del paradigma actual, y se propone un nuevo concepto de \emph{equidad centrada en el usuario}, desarrollando a su vez algoritmos descentralizados que se pueden aplicar en los extremos de la red, y que conducen al sistema a un global adecuado. El segundo problema importante analizado aquí es la asignación de los recursos realizada por los algoritmos de control de congestión cuando trabajan sobre una capa física que permite múltiples velocidades de transmisión como es el caso en las redes inalámbricas. Se demuestra que los algoritmos usuales conducen a ineficiencias importantes desde el punto de vista de las conexiones, y se proponen mecanismos para superar estas ineficiencias y mejorar la asignación de los recursos prestados por dichas redes. A lo largo de este trabajo, se aplican varias herramientas matemáticas, tales como la optimización convexa, la teoría de control y los procesos estocásticos. Por medio de estas herramientas, se construye un modelo del sistema, y se desarrollan leyes de control y algoritmos para lograr el objetivo de desempeño deseado. Como paso final, estos algoritmos fueron probados a través de simulaciones a nivel de paquetes de las redes involucradas, proporcionando la validación de la teoría y la evidencia de que pueden aplicarse en la práctica

사용자 중심의 밀리미터파 통신 시스템을 위한 이동성 인식 분석 프레임워크 및 네트워크 관리 기법

학위논문 (박사) -- 서울대학교 대학원 : 공과대학 전기·정보공학부, 2021. 2. 박세웅.Millimeter wave (mmWave) communication enables high rate transmission, but its network performance may be degraded significantly due to blockages between the transmitter and receiver. There have been two approaches to overcome the blockage effect and enhance link reliability: multi-connectivity and ultra-dense network (UDN). Particularly, multi-connectivity under a UDN environment facilitates user-centric communication. It requires dynamic configuration of serving base station groups so that each user experiences high quality services. This dissertation studies a mathematical framework and network manament schemes for user-centric mmWave communication systems. First, we models user mobility and mobility-aware performance in user-centric mmWave communication systems with multi-connectivity, and proposes a new analytical framework based on the stochastic geometry. To this end, we derive compact mathematical expressions for state transitions and probabilities of various events that each user experiences. Then we investigate mobility-aware performance in terms of network overhead and downlink throughput. This helps us to understand network operation in depth, and impacts of network density and multi-connection capability on the probability of handover related events. Numerical results verify the accuracy of our analysis and illustrate the correlation between mobility-aware performance and user speed. Next, we propose user-oriented configuration rules and price based association algorithms for user-centric mmWave networks with fully/partially wired backhauls. We develop a fair association algorithm by solving the optimization problem that we formulate for mmWave UDNs. The algorithm includes an access price based per-user request decision method and a price adjustment rule for load balancing. Based on insights from the algorithm, we develop path-aware access pricing policy for mmWave integrated access and backhaul networks. Numerical evaluations show that our proposed methods are superior to other comparative schemes. Our findings from analysis and optimization provide useful insights into the design of user-centric mmWave communication systems.밀리미터파 통신은 고속 전송을 가능하게 하지만 송신기와 수신기 사이의 장애물로 인해 네트워크 성능이 크게 저하될 수 있다. 장애물 효과를 극복하고 링크 안정성을 향상시키는 다중 연결 및 네트워크 초고밀화 두가지 접근법이 있다. 특히 각 사용자가 고품질의 서비스를 경험할 수 있도록 서빙 기지국 그룹의 동적 구성이 필요하므로 초고밀도 네트워크 환경에서 다중 연결은 사용자 중심 통신을 용이하게 한다. 본 논문은 사용자 중심의 밀리미터파 통신 시스템을 위한 수학적 프레임워크와 네트워크 관리 체계를 연구한다. 먼저 다중 연결을 사용하여 사용자 중심의 밀리미터파 통신 시스템에서 사용자 이동성과 이동성 인식 성능 지표를 모델링하고 확률기하분석을 기반으로 하는 새로운 분석 프레임워크를 제안한다. 이를 위해 각 사용자가 경험하는 다양한 이벤트의 상태 전이 확률에 대한 수학적 표현을 도출한다. 그런 다음 네트워크 오버헤드 및 다운 링크 수율 측면에서 이동성 인식 성능을 연구한다. 이를 통해 네트워크 운영에 대한 깊이있는 이해와 네트워크 밀도 및 다중 연결 기능이 핸드 오버와 관련된 이벤트의 확률에 미치는 영향을 이해할 수 있다. 시뮬레이션 결과는 분석의 정확성을 검증하고 이동성 인식 성능과 사용자 속도 간의 상관 관계를 보여준다. 다음으로 완전 또는 부분 유선 백홀이 있는 사용자 중심 밀리미터파 네트워크를 위한 사용자 중심 구성 규칙 및 접속 가격 기반 연결 알고리즘을 제안한다. 밀리미터파 초고밀도 네트워크에 대한 최적화 문제를 해결하여 공정한 연결 알고리즘을 개발한다. 이 알고리즘에는 접속 가격 기반 사용자 별 요청 결정 방법과 로드 밸런싱을 위한 가격 조정 규칙이 포함된다. 위 알고리즘 개발을 통해 얻은 통찰력을 기반으로 밀리미터파 통합 액세스 및 백홀 네트워크를 위한 경로 인식 접속 요금 정책을 개발한다. 수치 평가에 따르면 제안된 방법이 다른 비교 기법보다 우수하다. 분석 및 최적화 결과는 사용자 중심의 밀리미터파 통신 시스템 설계에 대한 유용한 통찰력을 제공할 것 이다.Abstract i Contents iii List of Tables vi List of Figures vii 1 Introduction 1 1.1 Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.2 Outline and Contributions . . . . . . . . . . . . . . . . . . . . . . . . 3 2 Mobility-Aware Analysis of MillimeterWave Communication Systems with Blockages 5 2.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 2.1.1 Related Work . . . . . . . . . . . . . . . . . . . . . . . . . . 6 2.1.2 Contributions . . . . . . . . . . . . . . . . . . . . . . . . . . 8 2.2 System Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 2.2.1 Network Model . . . . . . . . . . . . . . . . . . . . . . . . . 9 2.2.2 Connectivity Model . . . . . . . . . . . . . . . . . . . . . . 10 2.2.3 Mobility Model . . . . . . . . . . . . . . . . . . . . . . . . . 11 2.3 Mobility-Aware Analysis . . . . . . . . . . . . . . . . . . . . . . . . 13 2.3.1 Analytical Framework . . . . . . . . . . . . . . . . . . . . . 13 2.3.2 Urban Scenario with Ultra-Densely Deployed BSs . . . . . . 18 2.3.3 Handover Analysis for Macrodiversity . . . . . . . . . . . . . 22 2.3.4 Normalized Network Overhead and Mobility-Aware Downlink Throughput with Greedy User Association . . . . . . . . 24 2.4 Numerical Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 2.5 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 3 Association Control for User-Centric Millimeter Wave Communication Systems 34 3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 3.2 System Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 3.2.1 Network Model . . . . . . . . . . . . . . . . . . . . . . . . . 37 3.2.2 Channel Model and Achievable Rate . . . . . . . . . . . . . . 39 3.2.3 User Centric mmWave Communication Framework . . . . . . 39 3.3 Traffic Load Management . . . . . . . . . . . . . . . . . . . . . . . . 44 3.3.1 Optimal Association and Admission Control . . . . . . . . . 45 3.3.2 Outage Analysis . . . . . . . . . . . . . . . . . . . . . . . . 51 3.4 Performance Evaluation . . . . . . . . . . . . . . . . . . . . . . . . . 53 3.4.1 Evaluation Environments . . . . . . . . . . . . . . . . . . . . 53 3.4.2 Performance Comparison . . . . . . . . . . . . . . . . . . . . 55 3.5 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 4 Path Selection and Path-Aware Access Pricing Policy in Millimeter Wave IAB Networks 60 4.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 4.2 System Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62 4.2.1 Geographic and Pathloss Models . . . . . . . . . . . . . . . . 62 4.2.2 IAB Network Model . . . . . . . . . . . . . . . . . . . . . . 63 4.3 Path Selection Strategies . . . . . . . . . . . . . . . . . . . . . . . . 66 4.4 Path-Aware Access Pricing Policy . . . . . . . . . . . . . . . . . . . 69 4.5 Performance Evaluation . . . . . . . . . . . . . . . . . . . . . . . . . 72 4.6 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78 5 Conclusion 80 5.1 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80 5.2 Limitations and Future Work . . . . . . . . . . . . . . . . . . . . . . 82 Abstract (In Korean) 90Docto

M/D/1/0 loss system with interference and applications to transmit-only sensor networks

We propose and analyze a probabilistic model of packet reception in the steady state regime of a non-slotted wireless communication channel. It is an extension of the classical M/D/1/0 Erlang's loss model where the {\em interference} created by different packet emissions is introduced by means of a shot-noise process. More precisely, we assume that a given {\em packet is admitted} by the single receiver if this latter is idle at the packet arrival epoch and {\em successfully received} if, in addition, its signal-to-interference-and-noise ratio averaged over the reception period is large enough. As the main result we prove an analog of the Erlang's formula for the ergodic rate of the successfully received packets. Our work is motivated by some applications to transmit-only sensor networks

Resource sharing in network slicing and human-machine interactions

In this thesis we explore two novel resource allocation models. The first addresses challenges associated with dynamic sharing of network resources by multiple tenants/services via network slicing. The second focuses on a data-driven approach to the optimization of resource allocation in interactive human-machine processes. In our first thrust we investigate how to allocate shared storage, computation, and/or connectivity resources distributed amongst multiple tenants/ virtual service providers which have dynamic loads. It is expected that next generation of wireless network will be shared by an increasing number of data-intensive mobile applications (e.g., autonomous cars, IoT, interactive 360° video streaming), and tenants/service providers. A key functional requirement for such infrastructure is enabling efficient sharing of heterogeneous resource among tenants/service providers supporting spatially varying and dynamic user demands, both from the point of view of enabling the deployment and performance management to diverse service providers and/or tenants, as well as means to increase utilization and reduce CAPEX/OPEX associated with deploying possible new infrastructures. To that end, we propose a novel dynamic resource sharing policy, namely, Share Constrained Proportional Fair (SCPF), which allocates a predefined ‘share’ of a pool of (distributed) resources to each slice. We provide a characterization of the achievable performance gains over General Processor Sharing (GPS), and Static Slicing (SS), i.e., fixed allocation of resources to slices. We also characterize the associated share dimensioning problem, asking when a particular set of load profiles and QoS requirements are feasible, as well as what should be an appropriate pricing strategy. We further consider possible slice-based admission control scheme where slices engage in an underlying game to maximize their carried loads subject to performance requirements. In order to accommodate settings where one would wish to provision different types of resources which are coupled through user demands, we generalize SCPF to a more general resource allocation criterion, namely, Share Constrained Slicing (SCS), which extends traditional α—fairness criterion, by striking a balance among inter- and intra-slice fairness vs. overall efficiency. We show that SCS has several desirable properties including slice-level protection, envyfreeness, and load-driven elasticity. In practice, mobile users' dynamics could make the cost of implementing SCS high, so we also study the feasibility of using a dynamically weighted max-min fair policy as a surrogate resource allocation scheme. For a setting with stochastic loads and elastic user requirements, we model the user dynamics under SCS as a queuing network and establish the stability condition. Finally, and perhaps surprisingly, we show via extensive simulation that while SCS (and/or the surrogate weighted max-min allocation) provides inter-slice protection, they can also achieve improved job delay and/or perceived throughput, as compared to other weighted max-min based allocation schemes whose intra-slice weight allocation is not share-constrained, e.g., traditional max-min and/or discriminatory processor sharing. In our second thrust we study how to optimize resource allocation in the context of human-machine interactions. Examples of such processes could include systems aimed at assisting humans in interactive learning, workload allocation, or web-search advertising. We devise an innovative framework to enable the optimization of a reward over an interactive process in a data-driven manner. This is a challenging problem for several reasons: (1) humans' behavior is not easily modeled and may reflect biases, memory and be sensitive to sequencing, all of which should/could be inferred from data; (2) because these interactions are typically sequential and transient, inferring such complex models for human behavior is difficult; (3) furthermore, in order to collect data on human-machine interactions one must choose a machine policy which in turn may bias inferences on human behavior. In this thesis we approach the problem of jointly estimating human behavior and optimizing machine policies via Alternating Entropy-Reward Ascent (AREA) algorithm. We characterize AREA in terms of its space and time complexity and convergence. We also provide an initial validation based on synthetic data generated by an established noisy nonlinear model for human decision-makingElectrical and Computer Engineerin

Efficient radio resource management for the fifth generation slice networks

It is predicted that the IMT-2020 (5G network) will meet increasing user demands and, hence, it is therefore, expected to be as flexible as possible. The relevant standardisation bodies and academia have accepted the critical role of network slicing in the implementation of the 5G network. The network slicing paradigm allows the physical infrastructure and resources of the mobile network to be “sliced” into logical networks, which are operated by different entities, and then engineered to address the specific requirements of different verticals, business models, and individual subscribers. Network slicing offers propitious solutions to the flexibility requirements of the 5G network. The attributes and characteristics of network slicing support the multi-tenancy paradigm, which is predicted to drastically reduce the operational expenditure (OPEX) and capital expenditure (CAPEX) of mobile network operators. Furthermore, network slices enable mobile virtual network operators to compete with one another using the same physical networks but customising their slices and network operation according to their market segment's characteristics and requirements. However, owing to scarce radio resources, the dynamic characteristics of the wireless links, and its capacity, implementing network slicing at the base stations and the access network xix becomes an uphill task. Moreover, an unplanned 5G slice network deployment results in technical challenges such as unfairness in radio resource allocation, poor quality of service provisioning, network profit maximisation challenges, and rises in energy consumption in a bid to meet QoS specifications. Therefore, there is a need to develop efficient radio resource management algorithms that address the above mentioned technical challenges. The core aim of this research is to develop and evaluate efficient radio resource management algorithms and schemes that will be implemented in 5G slice networks to guarantee the QoS of users in terms of throughput and latency while ensuring that 5G slice networks are energy efficient and economically profitable. This thesis mainly addresses key challenges relating to efficient radio resource management. First, a particle swarm-intelligent profit-aware resource allocation scheme for a 5G slice network is proposed to prioritise the profitability of the network while at the same time ensuring that the QoS requirements of slice users are not compromised. It is observed that the proposed new radio swarm-intelligent profit-aware resource allocation (NR-SiRARE) scheme outperforms the LTE-OFDMA swarm-intelligent profit-aware resource (LO-SiRARE) scheme. However, the network profit for the NR-SiRARE is greatly affected by significant degradation of the path loss associated with millimetre waves. Second, this thesis examines the resource allocation challenge in a multi-tenant multi-slice multi-tier heterogeneous network. To maximise the total utility of a multi-tenant multislice multi-tier heterogeneous network, a latency-aware dynamic resource allocation problem is formulated as an optimisation problem. Via the hierarchical decomposition method for heterogeneous networks, the formulated optimisation problem is transformed to reduce the computational complexities of the proposed solutions. Furthermore, a genetic algorithmbased latency-aware resource allocation scheme is proposed to solve the maximum utility problem by considering related constraints. It is observed that GI-LARE scheme outperforms the static slicing (SS) and an optimal resource allocation (ORA) schemes. Moreover, the GI-LARE appears to be near optimal when compared with an exact solution based on spatial branch and bound. Third, this thesis addresses a distributed resource allocation problem in a multi-slice multitier multi-domain network with different players. A three-level hierarchical business model comprising InPs, MVNOs, and service providers (SP) is examined. The radio resource allocation problem is formulated as a maximum utility optimisation problem. A multi-tier multi-domain slice user matching game and a distributed backtracking multi-player multidomain games schemes are proposed to solve the maximum utility optimisation problem. The distributed backtracking scheme is based on the Fisher Market and Auction theory principles. The proposed multi-tier multi-domain scheme outperforms the GI-LARE and the SS schemes. This is attributed to the availability of resources from other InPs and MVNOs; and the flexibility associated with a multi-domain network. Lastly, an energy-efficient resource allocation problem for 5G slice networks in a highly dense heterogeneous environment is investigated. A mathematical formulation of energy-efficient resource allocation in 5G slice networks is developed as a mixed-integer linear fractional optimisation problem (MILFP). The method adopts hierarchical decomposition techniques to reduce complexities. Furthermore, the slice user association, QoS for different slice use cases, an adapted water filling algorithm, and stochastic geometry tools are employed to xxi model the global energy efficiency (GEE) of the 5G slice network. Besides, neither stochastic geometry nor a three-level hierarchical business model schemes have been employed to model the global energy efficiency of the 5G slice network in the literature, making it the first time such method will be applied to 5G slice network. With rigorous numerical simulations based on Monte-Carlo numerical simulation technique, the performance of the proposed algorithms and schemes was evaluated to show their adaptability, efficiency and robustness for a 5G slice network

Analytical Performance Evaluation of Cooperative and Multi-Radio Concepts in Emerging Wireless Networks

<br/

A practical assessment of network orientated load control for the intelligent network

The purpose of this thesis is to assess a new method of controlling load in Intelligent Networks (INs). This will be done through the analysis of experimentation results and comparison with existing methods of IN load control. This exercise will result in the investigation and validation of the proposed benefits being offered by this new methodology and the unveiling of its disadvantages. The methodology is known as network-orientated load control for the IN. Network-orientated load control is demonstrated using the MARINER Service Traffic Load Control System developed by the European Commission’s Advanced Communication, Technologies and Services (ACTS) Multi-Agent Architecture for Distributed Intelligent Network Load Control and Overload Protection (MARINER) Project. This system is shown to be a network-orientated load control application operating at the service level, built specifically for Intelligent Networks. Network-orientated load control is then assessed by deploying the MARINER System on a model of the IN, and running an exhaustive series of experiments. These experiments are structured to test the proposed benefits, limitations and disadvantages of networkorientated load control. The conclusions drawn from the results of these trials are then compared with existing IN load control characteristics, and used to make an assessment of network-orientated load control for the Intelligent Network

Opportunistic packet scheduling algorithms for beyond 3G wireless networks

The new millennium has been labeled as the century of the personal communications revolution, or more specifically, the digital wireless communications revolution. The introduction of new multimedia services has created higher loads on available radio resources. Namely, the task of the radio resource manager is to deliver different levels of quality for these multimedia services. Radio resources are scarce and need to be shared by many users. This sharing has to be carried out in an efficient way avoiding, as much as possible, any waste in resources. A Heuristic scheduler for SC-FDMA systems is proposed where the main objective is to organize scheduling in a way that maximizes a collective utility function. The heuristic is later extended to a multi-cell system where scheduling is coordinated between neighboring cells to limit interference. Inter-cell interference coordination is also examined with game theory to find the optimal resource allocation among cells in terms of frequency bands allocated to cell edge users who suffer the most from interference. Activity control of users is examined in scheduling and admission control where in the admission part, the controller gradually integrates a new user into the system by probing to find the effect of the new user on existing connections. In the scheduling part, the activity of users is adjusted according to the proximity to a requested quality of service level. Finally, a study is made about feedback information in multi-carrier systems due to its importance in maximizing the performance of opportunistic networks