Distributed Energy Efficient Channel Allocation

IEEE 5th International Symposium on Wireless Pervasive Computing 2010, 2010

The energy consumption of wireless access networks amounts for more than 55% of the whole communication sector and for a non negligible part of the operational costs of mobile operators. In this paper we consider possible energy savings through optimized management of on/off state and transmission power of access stations according to traffic estimates in different hours of the day or days of the week. We propose an optimization approach based on a ILP model that minimizes power consumption while ensuring coverage of the active users and enough capacity for guaranteeing quality of service. Proposed model is solved to the optimum on a set of randomly generated instances that show the effect of system parameters on optimal power consumption.

2016

State-of-the-art algorithms for energy-efficient resource allocation in wireless networks are based on fractional programming theory, and are able to find the global maximum of the system energy efficiency only in noise-limited scenarios. In interference-limited scenarios, several sub-optimal solutions have been proposed, but an efficient framework to globally maximize energy-efficient metrics is still lacking. The goal of this work is to fill this gap, which will be achieved by merging fractional programming theory with monotonic optimization theory. The resulting optimization framework is useful for at least two main reasons. First, it sheds light on the ultimate energy-efficient performance of wireless networks. Second, it provides the means to benchmark the energy efficiency of practical, but sub-optimal, solutions.

Computer Networks, 2011

The energy consumption of wireless access networks is rapidly increasing and in some countries it amounts for more than 55% of the whole communication sector and for a non negligible part of the operational costs of mobile operators. The new wireless technologies with a growth of data rates by a factor of roughly 10 every 5 years and the increase in the number of users result in a doubling of the power consumption of cellular networks infrastructure every 4-5 years-to 60 TWh in 2007. In this paper we consider possible energy savings through optimized management of on/off state and transmitted power of access stations according to traffic estimates in different hours of the day or days of the week. We propose an optimization approach based on some ILP models that minimizes energy consumption while ensuring area coverage and enough capacity for guaranteeing quality of service. Proposed models capture system characteristics considering different management constraints that can be considered based on traffic requirements and application scenarios. Energy minimization problems are solved to the optimum or with a gap to the optimum of less than 2.7% on a set of synthetic instances that are randomly generated. Obtained results show that remarkable energy savings, up to more than 50%, can be obtained with the proposed management strategies.

Computer Communications, 2011

The power consumption of wireless access networks will become an important issue in the coming years. In this paper, the power consumption of base stations for mobile WiMAX, fixed WiMAX, UMTS, HSPA, and LTE is modelled and related to the coverage. A new metric, the power consumption per covered area P C area , is introduced, to compare the energy efficiency of the considered technologies for a range of bit rates. Assuming the model parameters are correct, the conclusions are then as follows. For a 5 MHz channel, UMTS is the most energy-efficient technology until a bit rate of 2.8 Mbps, LTE between 2.8 Mbps and 8.2 Mbps, fixed WiMAX between 8.2 Mbps and 13.8 Mbps and finally mobile WiMAX for bit rates higher than 13.8 Mbps. Furthermore, the influence of MIMO is investigated. For a 2x2 MIMO system, P C area decreases by 36 % for mobile WiMAX and by 23 % for HSPA and LTE compared to the SISO system, resulting in a higher energy efficiency. The power consumption model for base stations is used in the deployment tool GRAND (Green Radio Access Network Design) for green wireless access networks. GRAND uses a genetic based algorithm and is applied on an actual case for the Brussels Capital Region, showing the possibilities of energy-efficient planning.

During the last few years there has been a significant growth in the field of wireless communication. Power optimization is an important task for NGN (Next Generation Network), because near about 7-8 % weightage of ICT (Information and Communication Technology) power are being used in mobile communication. In this paper tools and techniques are provided for optimizing total power consumption of a Wireless Network due to repeated data processing and inefficient transmission to a fixed end-to-end source. In this work it is shown that the improved transmission strategy could enhance and optimize the total power utilization considerably. Power optimization in wireless network has been analyzed on the basis of three case study which are: 1) Relay based Approach, 2) Battery Model, and 3) Routing Protocol. The proposed network is compared among various scenarios and on the basis of performance analysis, the proposed model provides a best solution for NGN with AODV routing protocol as compared with OLSR as far as power optimization is concerned.

2010 IEEE 21st International Symposium on Personal, Indoor and Mobile Radio Communications Workshops, 2010

Energy efficiency becomes evergreen than ever before. Over the last few years a significant research in wireless communications, aiming to enhance communications efficiency subject to constraint of power consumption, has given rise to optimization techniques of power control and management in wireless networks. Although the initial target was the utilization of resources in order to exploit communications services, the benefits of this effort, underlying the green perspective, are now opening eyes out to research community for a more green matter of conscience in use of communication equipment and devices. Towards this direction and affected by a green sensitivity in terms of wasting useful resources, we propose a system model for infrastructure WiFi networks aiming to reduce the consumed power, by introducing a scheme for channel allocation to Wireless LANs under energy conserving criteria.

2010 4th International Symposium on Communications, Control and Signal Processing (ISCCSP), 2010

Due to increasing data traffic rates and rollout of advanced radio transmission technologies wireless networks consume increasing amount of energy and contribute a growing fraction to the CO 2 emissions of ICT industry. Thus, climate and cost issues now shift the research focus of wireless communications to energy consumption and energy efficiency. Two approaches can be followed: Incremental improvements of existing systems or a clean slate re-design with a fundamental change of paradigms. We describe two such initiatives and discuss their differences. The EC FP7 project EARTH is a 30 month project aiming for a reduction of the overall energy consumption of 4G mobile broadband networks by 50%, regarding network aspects and individual radio components from a holistic point of view. The Green Touch Initiative is a privately financed consortium addressing fundamental research that will pave the way to much higher reductions for future systems in the order of several magnitudes, with first proof of concepts available in 5 years.

2006

Most mobile devices in wireless networks have limited energy storage capability. Similar limitations can apply to fixed devices found in sensor networks and in the longer haul relay stations in rural networks. Current research on battery technologies shows that only small improvements in the battery capacity are expected in the near future. Thus, in order to make the wireless networks (especially rapidly deployed networks) available commercially, we need to reduce the energy consumption in wireless devices. There are two main approaches to the problem. The first approach is to reduce the energy consumption of electronic circuits in wireless devices. The second approach is to design energy based routing techniques, including some modifications on medium access control (MAC) layer to reduce the energy consumption of wireless devices in networks. The second approach is focused in this paper.

2009 IEEE International Conference on Communications Workshops, 2009

In this paper we study with simple analytical models the energy-aware management of cellular access networks, trying to characterize the amount of energy that can be saved by reducing the number of active cells during the periods when they are not necessary because traffic is low. When some cells are switched off, radio coverage and service provisioning are taken care of by the cells that remain active, so as to guarantee that service is available over the whole area. We show how to optimize the energy saving, first assuming that any fraction of cells can be turned off, and then accounting for the constraints resulting from the cell layout.

IEEE Communications Surveys & Tutorials, 2014

Traditionally, energy efficiency aspects have been included in the wireless access network design space only in the context of power control aimed at interference mitigation, and for the increase of the terminal battery lifetime. Energy consumption of network components has also, for a long time, not been considered an issue, neither in equipment design, nor in network planning and management. However, in recent years, with the user demand increasing at nearly exponential pace, and margins rapidly shrinking, concerns about energy efficiency have been raised, with the objective to reduce network operational costs (not to mention the environmental issues). Installing more energyefficient hardware does not seem to fully solve the problem, since wireless access networks are almost invariably (over)provisioned with respect to the peak user demand. This means that efficient resource management schemes, capable of controlling how much of the network infrastructure is actually needed and which parts can be temporarily powered off to save energy, can be extremely effective and provide quite large cost reductions.