3G UMTS WCDMA Frequency Bands & UARFCN
- there are many UMTS WCDMA frequency bands around the globe used which fall within internationally agreed allocations. The channels are given a UARFCN which uniquely defines the frequency channel or frequency band..
There are very many frequency bands that are used to carry the 3G UMTS transmissions.
These frequency bands are allocated on an international basis to enable roaming and also to allocate bands internationally to minimise interference.
UMTS frequency bands background
As the use of 3G UMTS has grown, so too has the requirement for frequency allocations. Initially bands in the region of 1885 - 2025 and 2110 - 2200 MHz were set aside.
These frequency bands were originally set aside at the World Administrative radio Conference in 1992, to enable use on a worldwide basis by administrations wishing to implement International Mobile Telecommunications-2000, IMT-2000.
As the requirement for additional spectrum grew with the increased use of 3G UMTS, more allocations were set aside.
Although not all bands are available in all countries, all bands are managed on an international basis. In this way roaming is possible.
3G UMTS bandwidth
UMTS uses wideband CDMA as the radio transport mechanism and the UMTS channels are spaced by 5 MHz.
The UMTS signal bandwidth is normally considered to be 5 MHz but this figure includes the 0.58 MHz guard bands either side.
Therefore when the two guard bands, one either side, are excluded this leaves and effective signal bandwidth of 3.84 MHz within the flat response area of the signal for the transmission itself.
It is also necessary to consider the roll-off factor for the signal of 0.22. This roll-off factor is determined by the Root Raised Cosine filter specified by 3GPP. This means that the total signal bandwidth increasing the skirts is 4.68 MHz.
It is also worth noting that the bandwidth used for the TD-SCDMA variant of 3G UMTS used in China is 1.6 MHz.
UARFCN channel numbers
UMTS carrier frequencies are designated by a UTRA Absolute Radio Frequency Channel Number, UARFCN. The UARFCN is used to define channel numbers in an easy and unambiguous fashion.
The UARFCN can be easily calculated from the following equation or formula:
The UARFCN is only able to represent channels that are centred on a multiple of 200 kHz and these do not always align with licensing in North America. Accordingly 3GPP added several special values for the common North American channels.
3G UMTS frequency bands - FDD
As FDD, frequency division duplex requires bands for uplink and downlink, the bands for FDD are different to those required for TDD time division duplex.
The main UMTS / WCDMA frequency bands for FDD operation are summarised below:
|3G UMTS Frequency Bands - FDD|
|Band Number||Band||Common Name||UL Frequencies||DL Frequencues|
|1||2100||IMT||1920 - 1980||2120 - 2170|
|2||1900||PCS A-F||1850 - 1910||1930 - 1990|
|3||1800||DCS||1710 - 1785||1805 - 1880|
|4||1700||AWS A-F||1710 - 1755||2110 - 2155|
|5||850||CLR||824 - 849||869 - 894|
|6||800||830 - 840||875 - 885|
|7||2600||IMT-E||2500 - 2570||2620 - 2690|
|8||900||E-GSM||880 - 915||925 - 960|
|9||1700||1749.9 - 1784.9||1844.9 - 1879.9|
|10||1700||EAWS A-G||1710 - 1770||2110 - 2170|
|11||1500||LPDC||1427.9 - 1447.9||1475.9 - 1495.9|
|12||700||LSMH||699 - 716||729 - 746|
|13||700||USMH C||777 - 787||746 - 756|
|14||700||USMH D||788 - 798||758 - 768|
|19||800||832.4 - 842.6||877.4 - 887.6|
|20||800||EUDD||832 - 862||791 - 821|
|21||1500||UPDC||1447.9 - 1462.9||1495 - 1510.9|
|22||3500||3410 - 3490||3510 - 3590|
|25||1900||EPCS A-G||1850 - 1915||1930 - 1995|
|26||850||ECLR||814 - 849||859 - 894|
Frequency bands 15, 16, 17, 18, 23 and 24 are now reserved frequency bands.
3G UMTS frequency bands - TDD
The main UMTS frequency bands for TDD operation are summarised below.
|3G UMTS Frequency Bands - TDD|
|Band Reference||Band Name||Frequencies|
|A Lower||IMT||1900 - 1920|
|A Upper||IMT||2010 - 2025|
|B Lower||PCS||1850 - 1910|
|B Upper||PCS||1930 - 1990|
|C||PCS duplex gap||1910 - 1930|
|D||IMT-E||2570 - 2620|
|E||2300 - 2400|
|F||1880 - 1920|
It is also noted that several of the UMTS frequency bands overlap or share similar frequencies. This is because the allocations are different in different areas, and each frequency band definition is given a new band number for that particular band.
By Ian Poole
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