... for the Next Generation 11 Evolution of Mobile Networks and Services 31.1 TheEvolutionofMobileNetworks 41.2 TrendsinMobileServices 61.3 WhyNext -generation( XG)MobileSystems? 91.4 Next- generationImperatives ... interworking among WLAN and external networks, and radio resource management.Higher data rates requires broad frequency bands, and sufficient broadband can beachieved in higher frequency bands. Since the ... broader channel bandwidth, and by increased performance requirements.Keeping the leadership in radio access technologies, NTT DoCoMo proposes VSF-OFCDM and VSCRF-CDMA for XG broadband radio access....