Cognitive radio and cooperative strategies for power saving in multi-standard wireless devices
ABSTRACT Energy is a critical resource in the design of wireless networks since wireless devices are usually powered by batteries. Without any new approaches for energy saving, 4G mobile users will relentlessly be searching for power outlets rather than network access, and becoming once again bound to a single location. To avoid the so called 4G “energy trap” and to help wireless devices become more environment friendly, there is a clear need for disruptive strategies to address all aspects of power efficiency from the user devices through to the core infrastructure of the network and how these devices and equipment interact with each other. The ICT-C2POWER project is the vehicle that will address these issues through cognitive techniques and cooperation. The C2POWER case study is to research, develop and demonstrate energy saving technologies for multi-standard wireless mobile devices, exploiting the combination of cognitive radio and cooperative strategies, while still enabling the required performance in terms of data rate and QoS to support active applications.
Conference Proceeding: The performance of active cooling in a mobile phone[show abstract] [hide abstract]
ABSTRACT: Power dissipation levels in mobile electronics devices are heading towards five watts and above. With this power dissipation level, products such as mobile phones will require active cooling to ensure that the devices operate within an acceptable temperature envelop from both user comfort and reliability perspectives. To the authors knowledge no studies to date have been carried out to determine the potential performance of fans within mobile phone architectures. In this paper a centrifugal fan is implemented into a Nokia mobile phone. Its performance is compared in terms of aerodynamic characteristics, maximum phone surface temperature, and allowable phone heat dissipation, for various levels of blockage in the phone, which are simulated using perforated plates with varying porosity. The results show that for the best case scenario, with minimal blockage increased power dissipation levels of order 75% can be achieved but with realistic blockages this value is more likely to be in the region of 50%.Thermal and Thermomechanical Phenomena in Electronic Systems, 2008. ITHERM 2008. 11th Intersociety Conference on; 06/2008
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ABSTRACT: CoolSpots enable a wireless mobile device to automatically switch between multiple radio interfaces, such as WiFi and Bluetooth, in order to increase battery lifetime. The main contribution of this work is an exploration of the policies that enable a system to switch among these interfaces, each with diverse radio characteristics and different ranges, in order to save power – supported by detailed quantitative measurements. The system and policies do not require any changes to the mobile applications themselves, and changes required to existing infrastructure are minimal. Results are reported for a suite of commonly used applications, such as file transfer, web browsing, and streaming media, across a range of operating conditions. Experimental validation of the CoolSpot system on a mobile research platform shows substantial energy savings: more than a 50% reduction in energy consumption of the wireless subsystem is possible, with an associated increase in the effective battery lifetime.01/2006;