Next generation cellular mobile networks

Energy efficiency and flexibility in the use of the radio spectrum resources are two major research challenges for the development of future wireless communications technologies.

On the one hand, many electromagnetic spectrum measurements reflect a great temporal and geographical variability in the usage of most assigned spectral bands, which, under fixed spectrum assignment policies are sporadically used. This fact, together with the limited amount of available radio spectrum, is spurring interest in Cognitive Radio techniques. Cognitive Radio is a promising concept that allows unlicensed (or secondary) users access to licensed bands in an opportunistic manner, as long as interference with licensed (or primary) users does not degrade the Quality-of-Service for the primary users.

On the other hand, data rates in wired and wireless networks are rising by a factor of roughly 10 every 5 years. However, this growth is produced at a cost of an enormous increase of power consumption of the equipment of cellular networks, duplicating power consumption every 4-5 years. Increasing the energy efficiency of network elements has thus become a key challenge of mobile networks operators.

To address these challenges, SPECTRA project (in which Wellness Telecom is involved) will develop a multi-band cognitive radio technology. New techniques for the global efficiency of wireless systems will be developed in the following four directions:

• the spectral efficiency thanks to the use of cognitive radio techniques in wireless systems,

• the energy optimization for wireless communications by optimizing architecture design and algorithms implementation,

• the minimization of the generated interference in the environment by selecting the adequate band which will guarantee the shortest transmission distance and the minimum power while preserving the Quality of Service.

The work of the project will be focused on three scenarios addressing commercial low-power femtocell scenarios, future relay-based cellular networks and professional and fast-deployable networks, expecting important improvements on power consumption, spectral efficiency and link reliability.

Funded by: Ministry of Industry, Tourism and Commerce within the National Plan for Research, Science, Development and Technological Innovation 2008-2011.
Reference Number: TSI-020400-2010-0080.

Funding Agencies:

 

Eolic farms could replace nuclear power stations

Japan was hit hard by the tsunami waves caused by the earthquake that hit its shores earlier this year. This natural disaster caused serious damage to the infrastructure of the country and its nuclear power plants, especially in Fukushima. This problem has the look of taxpayers about the dangers of power generation from dangerous materials such as uranium and has begun to talk seriously about the possibility of gradually replacing nuclear power stations to other sources less problematic.

Solar and wind have always been the first to be used when trying to get a renewable source, and in this respect Japan has been the exception. However, a nuclear power plant generates more energy than a typical solar or wind can provide, so Japan has begun looking for ways to improve the performance of these sources.

In this context, Yuji Ohya, a professor at Kyushu University has developed "Wind Lens", a concept introduced in the framework of the International Renewable Energy Exhibition in Yokohama (Japan). It is basically new type of wind turbine comprising a turbine with blades of more than 100 meters in diameter embedded in a ring-shaped structure. This ring acts as a "lens", intensifying the flow of the wind incident on the generator by multiplying the amount of electricity it can be generated by a traditional windmill.

While a turbine "Wind Lens" cannot compete with power generated by a nuclear plant, a "farm" could replace full of them quietly into a dangerous nuclear reactor. Ohya has planned to install these huge turbines on a hexagonal floating dock with dozens of these structures, and towed them out to sea. This approach will eliminate the critics who argue that wind farms are noisy and ruin the landscape. One or two miles offshore are out of sight, and the little noise produced cannot be heard from the coast.

Until now, "Wind Lens" is just a concept, and its creator has not yet decided its commercialization. Right now, wind energy represents about 2 percent of the world, with 159.2 gigawatts generated. The marketing of a generator like this could raise that percentage, producing electricity in a safe renewable way with a lower cost than the produced by traditional systems.

Source: ABC newspaper