资 源 简 介
Wirelesscommunications,especiallyinitsmobileform,hasbroughtusthefreedomofmobility
andhaschangedthelifestylesofmodernpeople.Waitingatafixedlocationtoreceiveormakea
phone call, or sitting in front of a personal computer to send an e-mail or download a video
program, has become an old story. Nowadays it is commonplace for people to talk over a cell
phonewhilewalkingonthestreet,ortodownloadandwatchamoviewhiletravelingonatrain.
Thisisthebenefitmadeavailabletousbythesuccessfulevolutionofwirelesscommunications
over three generations, with the fourth generation being under way.
