MadSci Network: Engineering
Query:

Re: hi can u tell me what is the frequency range in which the cdma works

Date: Sat Aug 21 16:04:30 2004
Posted By: Eric Maass, Director, semiconductors / communication products
Area of science: Engineering
ID: 1092976234.Eg
Message:

Dear Deepu Paul,

You are close regarding the frequency ranges that GSM uses, but in India 
there are two sets of uplink/downlink frequencies:
* 890-915 MHz range for the uplink (I think you confused this and said it 
was for downlink) fronm the handset to the base station,
* 935-960 MHz for the downlink, from the base station to the handset or 
cellular phone
*1710-1785 MHz for the uplink (another frequency band for more capacity)
*1805-1880 MHz for the downlink 

For CDMA in India, the frequencies are:
824 - 849 MHz for the uplink (handset to base station)
869 - 889 (or 894) MHz for the downlink (base station to handset)

There also was some discussion about allocating the 1880-1900 MHz 
frequencies for CDMA in India, but I haven't been able to confirm whether 
that frequency was actually allocated for CDMA.

The confusion about the 889 or 894 might be a spectral allocation issue in 
India. The CDMA frequencies correspond exactly to the spectral allocations 
in the USA for CDMA (IS-95 standard), but the U.S.A. downlink is from 869-
894 MHz, the same 25 MHz range as the uplink.  The frequency ranges for 
India were the same, except that the upper limit for India seems to be 889 
MHz (see the table in the article from the url listed below and the second 
source as well), a shortfall of  5 MHz. This might mean that India has some 
other allocation around 889-894 MHz with which they did not want CDMA to 
interfere.

References: http://www.businessworldindia.com/WebUserArticle.aspx?SectionId=382&
ArticleId=941
 http://www.businessworldindia.com/WebUserArticle.aspx?SectionId=382&
ArticleId=941


Best regards,
Eric 



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