23rd April 2010 at 12:46
#62349
varun sharma
Guest
Hi RAM,
Frequency is required to Trasnmit and receive signal over the channel.Channels having some frequencies.
uplink and downlink freqencies always different to avoid interference.
In CDMA band( 824-849MHZ : UL
869-894Mhz: DL)
for GSM 900: 890-915 MHZ: UL
935-960Mhz: DL
are using.
There are two technique:
FDD : Frequency division duplexing
TDD: Time division duplexing
In FDD different frequencies for uplink and downlink
In TDD same frequency but this is time shared.