hi, 1.please tel me in detail why do we say that for higher capacity we require more bandwidth? higher capacity means more data rate, meaning more bits per seconds(and i know BW is bps) but tell me in terms of frequencies availble in a band..coz we transmit our signal on 1 freq then what it has to do with the other freq in that band, when we transmit our signal after modulating it on some higher freq carrier then how does it actually travel in the air..what my understanding is that only sinusiods (with single frequency)travel then where is the data? and also what is the use of the bandwidth, let say if i modulate my signal on 2Ghz and it has a BW of say 500MHz then my antenna generates the signal of 2GHz sinusiod..so where is the data coz its just a plain sinusiod of 2G and also what are the other freq in that band doing?..does this antenna generate 2.1G, 2.2G also and propagates like a signal with variable frequencies to extract the data in terms of variation in freq??Plz explain..um so confused and i nkow um very bad with basics. 2. also why we say that more bits per seconds means more variations in the signal(in terms of time domain) and does more variations in the signal refer to more frequency componets present in that signal?