3G UMTS WCDMA ........ Frequency and Bandwidth
Lets begin with the very first question about a mobile communication technology "frequency range and Bandwidth"
.3G UMTS WCDMA technology works in which frequency range and what is the Bandwidth allocated?
In a sum we can say that 3G UMTS WCDMA technolgy works near about 2 GHz frequency range in 5Mhz sub Bands i.e a Service provider(Like AT&T,Vodafone) can get a Bandwidth in multiples of 5Mhz. Generally spectrum is allocated as 5 Mhz for UPLINK and 5Mhz for Downlink.(in *FDD) or 10 Mhz (in **TDD).
To be specific the 3G UMTS WCDMA technology works in IMT - 2000 frequency bands which was initially 1,885-2,025 Mhz and 2,110 - 2,200 Mhz but now it has been extended further.Below picture can give you better Idea of frequency allocation.
*FDD: Frequency division duplexing: In this kind of duplexing uplink and downlink used to happen on different frequency band.(It has a draw back of inefficient use of spectrum because we are assigning same BW(Bandwidth) to uplink as well as downlink but in real scenario Uplink traffic use to be far less than Downlink traffic. )
**TDD: Time division duplexing:In this kind of Duplexing whole frequency band is allocated for uplink as well as Downlink but in a given Time slot either you can send either Uplink data or Downlink Data. For TDD to work high synchronization needs B/W sender and receiver side.
Note:By uplink we are meaning data flow towards Base station from a User(or Mobile) where as downlink means data flow towards a user from Base station.
(For reference readers can check "Introduction to 3G Mobile communications " by Juha Korhonen)
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