C2POWER

The current and future demands for high speed connectivity, especially for mobile applications constrained by power consumption, drive us to investigate the current state of the art to further advance the technology for improved power efficiency. The truly mobile experience is to have the freedom to roam around anywhere and not be bound to a single location. On the other hand, the energy required to keep mobile devices connected to the network over extended periods of time quickly dissipates. In fact, energy is a critical resource in the design of wireless networks since wireless devices are usually powered by batteries. It is well known that battery life time is one of the top reasons why consumers do not frequently use advanced power hungry multimedia applications on their mobile devices. Battery capacity is finite and the progress of battery technology is very slow, with capacity expected to make little improvement in the near future. It is claimed that battery capacity has only increased by 80% within the last ten years, while the processor performance doubles every 18 months following Moore’s law. In terms of power consumption we have moved from a relatively low 1-2 W range in the first generations to around twice in 3G mobile devices. The perspective for the future does not look encouraging in this aspect, as one could easily expect another doubling in the power demand for 4G devices. From the mobile manufacturer’s perspective the energy consumption problem is critical, not only technically but also taking into account the market expectations from a newly introduced technology. This workshop looks into the cognitive radio and cooperative techniques for better power efficiency. Cooperative diversity can provide savings in the required transmit power because of the spatial diversity in the system. However, the extra processing and receiving power consumption at the relay and destination nodes for the cooperation gives rise to a trade-off between the gains in the transmit power and the losses in cooperation. Cognitive functionalities on the other hand can be used for context aware transmission schemes for better utilization of the energy.