the GSS thecnology what we use to brodcast TV channels works in mostly in 'c' band i think 2400 to 5000 Ghz band and works with 8 feet discs(also A band , Ku band), satelite is almost 36000 kms above in order to make it geo synchronous. each satelite has multiple transponder, this transponder (trans responder) receives the signal in hgher up link frequency and converts it to lower downlink frequency. signal atleast travels 72000 kms. this radio spectrum has properties like lightwaves and can be focused using parabolic reflectors. it is focused on a LNB/LNC i.e. Low Noice Blockdown Convertor and signal is then sent to a satelite receiver using 920 GHz. this satelite receiver further converts and demodulates the signal.

thats how TV broadcast works.

abhishek