Usage data in Japan do not show that video telephony is a real killer application for 3G. However, this may change if quality and market penetration improves or different marketing models are found. It is believed however that music is a killer application - compare for example the success of iPod. At the moment (3G-third generation) only very short music clips can be downloaded. 4G(fourth generation) is likely to enable the download of full length songs or music pieces which may change the market response dramatically. Music rights management will be a major issue to solve.