Energy Efficiency Metrics in Cognitive Radio Networks: A Hollistic Overview

Due to the explosive progression in the number of users for new generation wireless communication networks which includes cognitive radio networks, energy efficiency has been a fundamental factor affecting its development and performance.  In order to adeptly access and analyze the energy efficiency of a cognitive radio network, a standardized metric for this purpose is required. As a starting point, in this article we provided an analysis for energy efficiency metrics of a cognitive radio network in respect to its design and operation. The performance metrics and metrics developed at the different levels of a cognitive radio network are also studied. Establishing a comprehensive metric for evaluating, measuring and reporting the energy efficiency of cognitive radio networks is a crucial step in achieving an energy-efficient cognitive radio network

A Power Saving Network Architecture for Accessing the Internet from Mobile Computers: Design, Implementation and Measurements

In this paper we propose a power-saving strategy for accessing the Internet from a mobile computer. Firstly, we measure the power consumption of a mobile computer that uses a TCP connection to send/receive data from the Internet. These measurements indicate that, by adopting TCP, the power consumption is negatively affected by the congestion in the fixed network. To solve this problem we extend the Indirect TCP model to achieve both the TCP reliability and an optimal power consumption level. To test our claim we design and implement a Power-Saving Network Architecture based on an enhanced indirect TCP model. Experimental results show that our approach is a promising development, with respect to the classical TCP approach, to reduce power consumption. Specifically, in our experiments the power consumption, by exploiting the enhanced indirect model, is significantly lower than the power consumption measured when using the legacy TCP approach

Performance comparison of power saving strategies for mobile Web access

One of the critical issues in mobile Web access is the usage of limited energy resources of mobile computers. Unfortunately, the legacy TCP/IP architecture is very inefficient. This work proposes and analyzes power-saving strategies for mobile Web access. Specifically, in this paper we develop an energy-consumption model for Web transactions and, based on it, we propose and compare four different energy saving strategies: ideal, Indirect-TCP (I-TCP), local and global. The ideal strategy is unfeasible but it is used as a reference bound as it guarantees the lowest energy consumption. The other strategies have been implemented and compared in a real test-bed. The performance comparison is carried out by measuring two main performance figures: the energy spent for downloading a Web page, and the associated transfer-time. Experimental results show that relevant energy saving is achievable and that, among the feasible strategies, the global one gives the best performance: with this strategy we can save (on average) up to 88% of the energy. Furthermore, our results indicate that this power saving is obtained without a significant increase in the transfer-time perceived by the users (on average, 0.2s). Finally, by comparing the feasible strategies, we observe that the global one is much closer to the ideal case than the other strategies. In detail, the global strategy is about twice more efficient than the local one, and eight times more efficient than the I-TCP strategy

Energy consumption evaluation on the MAC layer of PRCSMA

En este proyecto se realizará un estudio de los actuales modelos de consumo energético para comunicaciones inalámbricas. El objetivo del trabajo es evaluar y optimizar el consumo de energía de un protocolo de acceso al medio diseñado para comunicaciones cooperativas: PRCSMA. Este protocolo está basado en el estándar IEEE 802.11 para redes de área local. La meta principal es identificar las condiciones bajo las que los esquemas de cooperación pueden resultar beneficiosos en términos de ahorro de energía consumida

Energy consumption evaluation on the MAC layer of PRCSMA

En este proyecto se realizará un estudio de los actuales modelos de consumo energético para comunicaciones inalámbricas. El objetivo del trabajo es evaluar y optimizar el consumo de energía de un protocolo de acceso al medio diseñado para comunicaciones cooperativas: PRCSMA. Este protocolo está basado en el estándar IEEE 802.11 para redes de área local. La meta principal es identificar las condiciones bajo las que los esquemas de cooperación pueden resultar beneficiosos en términos de ahorro de energía consumida

A survey of design techniques for system-level dynamic power management

Dynamic power management (DPM) is a design methodology for dynamically reconfiguring systems to provide the requested services and performance levels with a minimum number of active components or a minimum load on such components. DPM encompasses a set of techniques that achieves energy-efficient computation by selectively turning off (or reducing the performance of) system components when they are idle (or partially unexploited). In this paper, we survey several approaches to system-level dynamic power management. We first describe how systems employ power-manageable components and how the use of dynamic reconfiguration can impact the overall power consumption. We then analyze DPM implementation issues in electronic systems, and we survey recent initiatives in standardizing the hardware/software interface to enable software-controlled power management of hardware component