Energy-Delay Tradeoffs of Virtual Base Stations With a Computational-Resource-Aware Energy Consumption Model

The next generation (5G) cellular network faces the challenges of efficiency, flexibility, and sustainability to support data traffic in the mobile Internet era. To tackle these challenges, cloud-based cellular architectures have been proposed where virtual base stations (VBSs) play a key role. VBSs bring further energy savings but also demands a new energy consumption model as well as the optimization of computational resources. This paper studies the energy-delay tradeoffs of VBSs with delay tolerant traffic. We propose a computational-resource-aware energy consumption model to capture the total energy consumption of a VBS and reflect the dynamic allocation of computational resources including the number of CPU cores and the CPU speed. Based on the model, we analyze the energy-delay tradeoffs of a VBS considering BS sleeping and state switching cost to minimize the weighted sum of power consumption and average delay. We derive the explicit form of the optimal data transmission rate and find the condition under which the energy optimal rate exists and is unique. Opportunities to reduce the average delay and achieve energy savings simultaneously are observed. We further propose an efficient algorithm to jointly optimize the data rate and the number of CPU cores. Numerical results validate our theoretical analyses and under a typical simulation setting we find more than 60% energy savings can be achieved by VBSs compared with conventional base stations under the EARTH model, which demonstrates the great potential of VBSs in 5G cellular systems.Comment: 5 pages, 3 figures, accepted by ICCS'1

Improving cross-functional communication about product architecture

Product architecture decisions, such as product modularity, component commonality, and design reuse, are important for balancing costs, responsiveness, quality, and other important business objectives. Firms are challenged with complex tradeoffs between competing design priorities, face the need to facilitate communication between functional silos, and to learn from past experiences. In this paper we present a qualitative approach for systematically evaluating the product architecture of an existing product or product family, linking the original architecture objectives and actual experiences. The intended contribution of our research is to present a framework that brings together a diverse set of product architecture-related decisions that are relevant from a business point of view (and not from a technical point of view) and a set of business performance elements. This framework can be used in workshop that improves cross-functional communication about the product architecture of an existing product family, and this results in practical improvement actions for future architecture design projects. Initial experiences with this approach have been obtained in pilots with Philips domestic appliances & personal care, and Philips consumer electronics

On Morals, Markets, and Climate Change: Exploring Pope Francis’ Challenge

The relation between Culture and Business has caught researchers’ attention long ago; itis not hard to find studies relating to these topics. According to Hofstede et al. (2010, p.18), Hampden-Turner and Trompenaars (2012, p. 8), and Erez and Gati (2004, p. 5),culture can be defined in many levels, for example, organizational culture, and national culture. The field of Business also contains several disciplines, for example, International Business Management, Project Management, and Project Governance. However, not somany studies can be found studying the relation between National Culture and Project Governance; therefore, this study is focused on this relation.This study is designed following a qualitative approach in order to clarify the relation between National Culture and Project Governance Principles. Case studies are used targeting the IT industry of three countries, Spain, Sweden, and Taiwan. These cases also contain the classical theory of cultural dimensions from Hofstede. Hofstede’s dimensionsare Power Distance (PDI), Individualism vs. Collectivism (IDV), Uncertainty Avoidance(UAI), Masculinity vs. Femininity (MAS), Long-term Orientation (LTO), and Indulgencevs. Restraint (IDU). They are applied in this study for distinguishing the differences between countries. This study is also based on the definition of Project GovernancePrinciples from Garland (2009), Klakegg (2008), and Müller et al. (2013). ProjectGovernance Principles are split into two categories as well, hard/ structural principles andsoft/ behaviour principles.In order to clarify the link between National Culture and Project Governance Principles,this thesis’ authors interviewed 19 people, including 10 project managers and 9 experts.All of them have a long experience dealing with Project Management in the three selected countries. Their answers are based on the knowledge and experience of Project Management and Project Governance, as well as their opinions about their own national culture. After analysing the interviews, the authors consider that differences between these three countries in Project Governance and Project Governance Principles do exist. On the other hand, there are also some similar parts, for example, the influence ofcustomers’ orientation and preference. Moreover, respondents, Project Managers and Experts, all mentioned it is also necessary to be aware of the globalized environment, inother words, there is no influence of a single national culture in one country anymore.However, they all admit the importance of their own national culture as well. All these findings from this study encourage further and deeper study in the future

Evaluator services for optimised service placement in distributed heterogeneous cloud infrastructures

Optimal placement of demanding real-time interactive applications in a distributed heterogeneous cloud very quickly results in a complex tradeoff between the application constraints and resource capabilities. This requires very detailed information of the various requirements and capabilities of the applications and available resources. In this paper, we present a mathematical model for the service optimization problem and study the concept of evaluator services as a flexible and efficient solution for this complex problem. An evaluator service is a service probe that is deployed in particular runtime environments to assess the feasibility and cost-effectiveness of deploying a specific application in such environment. We discuss how this concept can be incorporated in a general framework such as the FUSION architecture and discuss the key benefits and tradeoffs for doing evaluator-based optimal service placement in widely distributed heterogeneous cloud environments