Anyone knows why GSM900 is called GSM900 with the number 900?
Is it because of the RF signal propogates at 900MHz
OR
the local oscillator used is oscillating at 900MHz?
900 singifies the center frequency, not related to local oscillator frequency.
Acutal details about of GSM system architecture can be found in
" Cellular and Mobile Communication " By C.Y. Lee
However the local oscillator also resonates at 900 Mhz only. But as far as nomenclature is concenrned the origin is unknown.
However some of the standard books suggests its due to the reason that frequencies used are around 900 Mhz.