Green radio: Energy efficiency in wireless networks

Rarely have technical innovations changed everyday life as fast and profoundly as the massive use of personal mobile communications. In the past two decades mobile wireless services grew from niche market applications to globally available components of daily life: The first GSM phone call took place in 1991 in Finland and only 15 years later there were over two billion GSM users. Today there are already more than 4 billion mobile phone subscribers in the world, more than half the population of the planet, and there are expected to be more than 1.2 billion mobile broadband subscribers by 2012. For the first time in history, worldwide mobile data traffic exceeded voice traffic in December 2009, a point which had already been reached in WCDMA networks in 2007.