Carrier Frequency and UARFCN Note: It’s a collection of information and if it violates any copyright issues please notify.
UMTS Frequencies The UMTS frequency bands are radio frequencies used by third generation (3G) wireless Universal Mobile Telecommunications System networks. They were allocated by delegate to the World Administrative Radio Conference (WARC-92) held in Málaga-Torremolinos, Spain between February 3, 1992 and March 3, 1992. There are currently six bands that are specified for use for UMTS / WCDMA although operation on other frequencies is not precluded. However much of the focus for UMTS is currently on frequency allocations around 2 GHz. At t he World Administrative radio Conference in 1992, the bands 1885 - 2025 and 2110 - 2200 MHz were set aside for use on a worldwide basis by administrations wishing to implement International Mobile Telecommunications-2000 (IMT-2000). The aim was that allocating spectrum on a worldwide basis would facilitate easy roaming for UMTS / WCDMA users. Within these bands the portions have been reserved for different uses:
1920-1980 and 2110-2170 MHz Frequency Division Duplex (FDD, W-CDMA) Paired uplink and downlink, channel spacing is 5 MHz and raster is 200 kHz. An Operator needs 3 - 4 channels (2x15 MHz or 2x20 MHz) to be able to build a high-speed, high-capacity network.
1900-1920 and 2010-2025 MHz Time Division Duplex (TDD, TD/CDMA) Unpaired, channel spacing is 5 MHz and raster is 200 kHz. Transmit and receive transmissions are not separated in frequency.
1980-2010 and 2170-2200 MHz Sate llite uplink and downlink.
UMTS carrier frequencies are designated by a UTRA Absolute Radio Frequency Channel Number (UARFCN). This can be calculated from: UARFCN = 5 x (frequency in MHz) UMTS uses wideband CDMA as the radio transport mechanism. The UMTS c hannels are spaced by 5 MHz
UARFCN The carrier frequency is designated by t he UTRA Absolute Radio Frequency Channel Number (UARFCN). For each operating Band, the UARFCN values are defined as follows: Uplink: NU = 5 * (FUL - FUL_Offset), for the carrier frequency range FUL_low ≤ FUL ≤ FUL_high Downlink: ND = 5 * (FDL - FDL_Offset), for the carrier frequency range FDL_low ≤ FDL ≤ FDL_high For each operating operating Band, Band, FUL_Offs FUL_Offset, et, FUL_low, FUL_low, FUL_high FUL_high,, FDL_Offset, FDL_Offset, FDL_low FDL_low and and
FDL_high FDL_high are
defined in Table 5.1 for the ge neral UARFCN. For the additional UARFCN, FUL_Offset, FDL_Offset and the specific FUL and FDL are defined in Table 5.1A.
DL UARFCN : 4436 (Band V) See the screen shot for understanding
As per the above calculation we will arrive with the below values. DL Center Freq : 887.2 MHz, UL Center Freq : 842.2 MHz Difference is 45 MHz
1)
Now DL will happen from (+/-) plus and minus 5 MHz from 887.2 MHz, hence 887.2 – 2.5 = 884.7, 887.2 + 2.5 = 889.7 889.7 Hence within the range of 5 MHz MHz downlink will happen. happen.
2)
UL will happen from (+/-) plus and minus 5 MHz from 842.2 MHz, hence 842.2 – 2.5 = 839.7, 842.2 + 2.5 = 844.7 Hence Hence within the range of 5 MHz MHz uplink will happen. happen.
3)
The difference between two center carrier freq is 45 MHz (887.2 – 842.2) because as per spec
25.101, Band V should have 45 KHz. 1. UMTS must operate in a frequency band defined by 3GPP TS 25.104. In FDD mode, the paired bands must have a minimum of 30MHz separation between the UL/DL .
2. The UARFCN (UTRA Absolute Radio Frequency Channel Number) is the channel number representing the full 5 MHz UMTS car rier. Only 3.84MHz is used for transmission, while the 116 MHz acts as a built-in guard-band to adjacent UARFC N's (580 kHz + 3840 kHz + 5 80 kHz = 5 MHz). If an operator owns the adjacent frequency bands, it is possible to reduce the size of the UMTS carrier from 5MHz to 4.4 or 4.2 MHZ, but t his is not recommended.
Channel spacing The nominal channel spacing is 5 MHz, but this can be adjusted to optimize performance in a particular deployment scenario. In DC-HSDPA and DB-DC-HSDPA mode, the UE receives two cells simultaneously. In context of DCHSDPA and DB-DC-HSDPA, a cell is characterized by a combination of scrambling code and a carrier frequency, see [21.905].
Channel raster The channel raster is 200 kHz, for all bands which means that the centre frequency must be an integer multiple of 200 kHz. In addition a number of additional centre frequencies are specified according to table 5.1A, which means that the centre frequencies for these channels are shifted 100 kHz relative to the general raster. E.G : 4436 DL Freq 887.2, UL Freq 842.2 4437 DL Freq 887.4, UL Freq 842.4 The above example shows the difference between the UARFCN is 1 and the carrier freq is .2(200 kHz)
