Mamdouh El Tabach

Bio: Mamdouh El Tabach is an academic researcher. The author has contributed to research in topics: Energy consumption & Service (business). The author has an hindex of 3, co-authored 7 publications receiving 16 citations.

Energy efficiency of a network per service

Abstract: We investigate in this paper the assessment of the energy efficiency of a wireless access network per service category. We consider five categories of service, two categories with high traffic: streaming and web browsing, and three other with lower traffic: download, voice and other minor data services. We introduce two scenarios, one where some services are mandatory, it is typically the case of Voice which is mandatory to be provided due to legal constraints, and another one where there is no mandatory service. We used our Shapley-based sharing model introduced in previous works to share the total energy consumption of the access network among the service categories, and then derive the energy efficiency of each service category as the ratio of its traffic volume (measured in the network) and its energy consumption assessed with our Shapley-based model. We applied the models on a real dataset extracted from an operational network in Europe, and analyze the energy efficiency of each considered service category.

Sharing of energy among service categories in wireless access networks using Shapley value

Abstract: We investigate in this paper the sharing of energy consumption among service categories in the access of a wireless network. We focus on the fixed part of the energy consumption of the network, which is known to be significantly larger than the load-dependent variable part, and propose its sharing among the service categories based on coalition game concept, the Shapley value. We consider five service categories, two large players: streaming and web browsing, and three smaller ones: download, voice and other minor services, and compare our proposal with two other sharing strategies: uniform and proportional which follows the same volume proportions. Our results, applied on a real dataset extracted from an operational network in Europe, show that our proposal is more fair both towards small services in that it reduces their shares in comparison to the uniform approach, and towards larger services as it reduces their shares in comparison with the proportional one. Indeed, our Shapley-based model accommodates both short term network behavior, in which the fixed energy component is independent of the traffic load, and longer term behavior, in which it varies with the load and infrastructure. Uniform sharing accounts only for the short term, and the proportional one only for the longer term.

Statistical power consumption assessment of mobile access networks at country level

Abstract: In this paper, we tackle the problem of assessment of the electrical power consumption of mobile access networks at country level. We focus on radio access sites hosting 2G and 3G base stations and their corresponding technical environment. First, we enrich and validate the existing analytical model that was proposed for power consumption at sites level in a scale of a country. We show that the fine-tuned analytical modeling yields interesting results only at global level but with strong a priori constraints on the impacting parameters. Then we propose a statistical model based on linear regression to estimate the total power consumption. The statistical model is tested and validated on real measurement from a whole network of European country. We show that, the proposed model is very efficient to predict the total power consumption of the entire studied network with a small training dataset and reduced number of input parameters. Indeed, with a training set of 30 sites (6% of sites), the global power consumption of the entire network is estimated within a 10% of margin at 95% of confidence level.

Energy modeling and optimization of radio access network using stochastic deployment models

Abstract: Operators are studying different solutions and scenarios of future networks that could sustain the expected traffic huge demand while maintaining a good quality of service and reducing environmental impact. In this paper, the optimal BS (Base Station) density for cellular networks to minimize network energy cost is analyzed with stochastic geometry theory. We provide an analytic expression of the optimum while taking into account different parameters including the technical environment of base stations, broadcasting power, data transmission power and radio environment. We use the developed model to analyze the power consumption of a recently introduced green network scenario were signaling and data are handled by different BS in the wireless access network. Based on the parameters from GreenTouch, we show that the recently introduced scenario compared to the traditional cellular network can reduce about 55% of the total energy cost in dense Urban area, and about 63% in rural areas.

Sharing the Network End-to-End Energy Consumption among Service Categories

Abstract: A network is a common resource typically shared by several services, and so, it is important to determine the share of each service in the total energy consumed by the network. The network energy consumption is composed of a variable component which is consumed to serve traffic, and a fixed component consumed irrespective of traffic. The share of a service in the variable energy consumption equals its traffic proportion as this energy component is load-dependent. In this paper, we focus on the fixed energy consumption and share the responsibility of the services transported by a end-to-end network in its fixed energy consumption. To do so, we use our model based on the cooperative game concept Shapley value introduced in a previous work [1] and apply it first to traffic, then to so-called useful outputs. According to ETSI, the useful output of an equipment is defined to be its maximum capacity and is expressed as the number of Erlangs, packets/s, subscribers, or simultaneously attached users. We consider seven network blocks composing the end-to-end path, namely, the radio access, the fixed access, the aggregation, the mobile core, the registers, the IP core and the service platforms. We consider five service categories: Streaming, Web, Download, other data services and Voice. We apply our model on a real data set extracted from an operational network in Europe, and analyze the end-to-end energy consumption assigned to the service categories.

博弈论 : 矛盾冲突分析 = Game theory : analysis of conflict

Abstract: Preface 1. Decision-Theoretic Foundations 1.1 Game Theory, Rationality, and Intelligence 1.2 Basic Concepts of Decision Theory 1.3 Axioms 1.4 The Expected-Utility Maximization Theorem 1.5 Equivalent Representations 1.6 Bayesian Conditional-Probability Systems 1.7 Limitations of the Bayesian Model 1.8 Domination 1.9 Proofs of the Domination Theorems Exercises 2. Basic Models 2.1 Games in Extensive Form 2.2 Strategic Form and the Normal Representation 2.3 Equivalence of Strategic-Form Games 2.4 Reduced Normal Representations 2.5 Elimination of Dominated Strategies 2.6 Multiagent Representations 2.7 Common Knowledge 2.8 Bayesian Games 2.9 Modeling Games with Incomplete Information Exercises 3. Equilibria of Strategic-Form Games 3.1 Domination and Ratonalizability 3.2 Nash Equilibrium 3.3 Computing Nash Equilibria 3.4 Significance of Nash Equilibria 3.5 The Focal-Point Effect 3.6 The Decision-Analytic Approach to Games 3.7 Evolution. Resistance. and Risk Dominance 3.8 Two-Person Zero-Sum Games 3.9 Bayesian Equilibria 3.10 Purification of Randomized Strategies in Equilibria 3.11 Auctions 3.12 Proof of Existence of Equilibrium 3.13 Infinite Strategy Sets Exercises 4. Sequential Equilibria of Extensive-Form Games 4.1 Mixed Strategies and Behavioral Strategies 4.2 Equilibria in Behavioral Strategies 4.3 Sequential Rationality at Information States with Positive Probability 4.4 Consistent Beliefs and Sequential Rationality at All Information States 4.5 Computing Sequential Equilibria 4.6 Subgame-Perfect Equilibria 4.7 Games with Perfect Information 4.8 Adding Chance Events with Small Probability 4.9 Forward Induction 4.10 Voting and Binary Agendas 4.11 Technical Proofs Exercises 5. Refinements of Equilibrium in Strategic Form 5.1 Introduction 5.2 Perfect Equilibria 5.3 Existence of Perfect and Sequential Equilibria 5.4 Proper Equilibria 5.5 Persistent Equilibria 5.6 Stable Sets 01 Equilibria 5.7 Generic Properties 5.8 Conclusions Exercises 6. Games with Communication 6.1 Contracts and Correlated Strategies 6.2 Correlated Equilibria 6.3 Bayesian Games with Communication 6.4 Bayesian Collective-Choice Problems and Bayesian Bargaining Problems 6.5 Trading Problems with Linear Utility 6.6 General Participation Constraints for Bayesian Games with Contracts 6.7 Sender-Receiver Games 6.8 Acceptable and Predominant Correlated Equilibria 6.9 Communication in Extensive-Form and Multistage Games Exercises Bibliographic Note 7. Repeated Games 7.1 The Repeated Prisoners Dilemma 7.2 A General Model of Repeated Garnet 7.3 Stationary Equilibria of Repeated Games with Complete State Information and Discounting 7.4 Repeated Games with Standard Information: Examples 7.5 General Feasibility Theorems for Standard Repeated Games 7.6 Finitely Repeated Games and the Role of Initial Doubt 7.7 Imperfect Observability of Moves 7.8 Repeated Wines in Large Decentralized Groups 7.9 Repeated Games with Incomplete Information 7.10 Continuous Time 7.11 Evolutionary Simulation of Repeated Games Exercises 8. Bargaining and Cooperation in Two-Person Games 8.1 Noncooperative Foundations of Cooperative Game Theory 8.2 Two-Person Bargaining Problems and the Nash Bargaining Solution 8.3 Interpersonal Comparisons of Weighted Utility 8.4 Transferable Utility 8.5 Rational Threats 8.6 Other Bargaining Solutions 8.7 An Alternating-Offer Bargaining Game 8.8 An Alternating-Offer Game with Incomplete Information 8.9 A Discrete Alternating-Offer Game 8.10 Renegotiation Exercises 9. Coalitions in Cooperative Games 9.1 Introduction to Coalitional Analysis 9.2 Characteristic Functions with Transferable Utility 9.3 The Core 9.4 The Shapkey Value 9.5 Values with Cooperation Structures 9.6 Other Solution Concepts 9.7 Colational Games with Nontransferable Utility 9.8 Cores without Transferable Utility 9.9 Values without Transferable Utility Exercises Bibliographic Note 10. Cooperation under Uncertainty 10.1 Introduction 10.2 Concepts of Efficiency 10.3 An Example 10.4 Ex Post Inefficiency and Subsequent Oilers 10.5 Computing Incentive-Efficient Mechanisms 10.6 Inscrutability and Durability 10.7 Mechanism Selection by an Informed Principal 10.8 Neutral Bargaining Solutions 10.9 Dynamic Matching Processes with Incomplete Information Exercises Bibliography Index

Distributed Energy-Spectrum Trading in Green Cognitive Radio Cellular Networks

Abstract: Reducing the power consumption of base stations is crucial to enhancing the energy efficiency of cellular networks. As the number of mobile users increases exponentially, enhancing the spectrum efficiency is also critical in order to accommodate more users. In this paper, by exploiting the cooperation between secondary base stations (SBSs) and primary base stations (PBSs), we propose a new energy spectrum trading model to enhance the energy as well as spectrum efficiency of cellular networks. In our scheme, by leveraging cognitive radio, PBSs share some portion of their licensed spectrum with SBSs, and SBSs, in exchange, provide data service to the primary users under their coverage. We first prove that the power consumption minimization problem is NP-hard. Then, to decrease the computational complexity, we design an efficient distributed auction model including green energy aware bidding (GEAB) and adaptive bid selection (ABS) algorithms, to achieve a good approximation of the optimal solution in less time. Our simulation results show that the cooperation between PBS and SBSs via ABS and GEAB algorithms can significantly improve the energy and spectral efficiency of cellular networks by nearly doubling the number of offloaded users and reducing the PBS power consumption by up to 40% as compared to existing approaches. Furthermore, green energy utilization among SBSs is increased by nearly 25%.

Unified and non-parameterized statistical modeling of temporal and spatial traffic heterogeneity in wireless cellular networks

Abstract: Understanding and solving performance-related issues of current and future (5G+) networks requires the availability of realistic, yet simple and manageable, traffic models which capture and regenerate various properties of real traffic with sufficient accuracy and minimum number of parameters. Traffic in wireless cellular networks must be modeled in the space domain as well as the time domain. Modeling traffic in the time domain has been investigated well. However, for modeling the User Equipment (UE) distribution in the space domain, either the unrealistic uniform Poisson model, or some non-adjustable model, or specifc data from operators, is commonly used. In this paper, stochastic geometry is used to explain the similarities of traffic modeling in the time domain and the space domain. It is shown that traffic modeling in the time domain is a special one-dimensional case of traffic modeling in the space domain. Unified and non-parameterized metrics for characterizing the heterogeneity of traffic in the time domain and the space domain are proposed and their equivalence to the inter-arrival time, a well accepted metric in the time domain, is demonstrated. Coefficient of Variation (CoV), the normalized second-order statistic, is suggested as an appropriate statistical property of traffic to be measured. Simulation results show that the proposed metrics capture the properties of traffic more accurately than the existing metrics. Finally, the performance of LTE networks under modeled traffic using the new metrics is illustrated.

SooGREEN: Service-oriented optimization of green mobile networks

Abstract: Today, mobile networks are witnessing an exponential growth of traffic volumes, linked to new services, especially for smart cities and smart-grid. The European Celtic-Plus SooGREEN project, started mid 2015, is targeting to reduce the energy consumption of the services in different mobile architectures in interaction with smart-grid. So GREEN is focused on the services energy consumption modelling and measurement, the dynamic optimization of the mobile access network and of the content delivery, the design of an Energy Efficient Virtualized and Centralized Radio Access Network (RAN), and the bi-directional interaction of the mobile network with the smart-grid. This paper presents insight into the project after its first year, and discusses research trends in green communication networks for the future.