Mobile Communication systems and antenna technologies for wireless broadband

Recent progress in wireless communication technologies has achieved a state in which users can communicate with anybody, anywhere at anytime. The feature of recent mobile communications, especially in Japan, is that the main type of traffic is not phone calls but packet data. People obtain various types of information via wireless Internet. Wireless communication systems such as IMT systems have already become an indispensable social infrastructure. In mobile communication systems, the second generation systems exemplified by Global System for Mobile Communications (GSM), have been popularized worldwide. Currently, the third generation system (IMT systems) are becoming the main stream system and their enhanced systems called Long Term Evolution (LTE) are being developed. The LTE service will be launched this year. Furthermore, standardization processes for the IMT-Advanced system, which is the enhanced system of LTE, have been initiated. The target maximum data rate in the IMT-Advanced system is up to 1 Gbps.