#FDMA( Frequency Division Multiple Access):

•frequency division multiple access designes individual channels to individual users. It can be seen from figure that each user is allocated a unique frequency band or channel this channelsare assigned on demand to user hu request services.
•during the same period of cell no other user can share the same channel. In FDD system the user are assigned of Channels as a pair of frequencies on frequency is used for what channel while the other frequencies used for the reverse channel.




• formula for, 

            N= Bt - 2Bguard / Bc
             
Where,
             N- total no.of channels
             Bt- total spectrum Bandwidth
             Bguard- guard Bandwidth
             Bc- channel Bandwidth