# Understanding LTE Carrier Frequency and EARFCN

CableFree LTE base stations use ETSI Industry Standard EARFCN to display channel numbers, rather than raw frequencies in MHz.  This may appear confusing at first glance but is the standard in LTE networks.  This article explains how to convert between LTE carrier Frequency and EARFCN numbers

## Introduction

EARFCN stands for E-UTRA Absolute Radio Frequency Channel Number.In LTE, the carrier frequency in the uplink and downlink is designated by EARFCN, which ranges between 0-65535.

• EARFCN uniquely identify the LTE band and carrier frequency.
For example Band-1 and Band-4 can have same Rx frequency 2110-2170 MHz,  but their EARFCN are different.
• EARFCN is independent of channel bandwidth.

## DOWNLINK (Base Station to CPE) and UPLINK (CPE to Base Station)

The relation between EARFCN and its uplink/downlink carrier frequency is given by the equation below

where,

NDLoffset = offset used to calculate downlink EARFCN
NULoffset = offset used to calculate uplink EARFCN

EARFCN of carrier frequency can be calculated with Eq-(1) or Eq-(2) using FDL_low, NOffs-DL, FUL_low and NOffs-UL given in table below.

Band FDL_low (MHz) NOffs-DL NDL Range FUL_low (MHz) NOffs-UL NUL Range
1 2110 0 0-599 1920 18000 18000-18599
2 1930 600 600-1199 1850 18600 18600-19199
3 1805 1200 1200-1949 1710 19200 19200-19949
4 2110 1950 1950-2399 1710 19950 19950-20399
5 869 2400 2400-2649 824 20400 20400-20649
6 875 2650 2650-2749 830 20650 20650-20749
7 2620 2750 2750-3449 2500 20750 20750-21449
8 925 3450 3450-3799 880 21450 21450-21799
9 1844.9 3800 3800-4149 1749.9 21800 21800-22149
10 2110 4150 4150-4749 1710 22150 22150-22749
11 1475.9 4750 4750-4949 1427.9 22750 22750-22949
12 729 5010 5010-5179 699 23010 23010-23179
13 746 5180 5180-5279 777 23180 23180-23279
14 758 5280 5280-5379 788 23280 23280-23379
17 734 5730 5730-5849 704 23730 23730-23849
18 860 5850 5850-5999 815 23850 23850-23999
19 875 6000 6000-6149 830 24000 24000-24149
20 791 6150 6150-6449 832 24150 24150-24449
21 1495.9 6450 6450-6599 1447.9 24450 24450-24599
22 3510 6600 6600-7399 3410 24600 24600-25399
23 2180 7500 7500-7699 2000 25500 25500-25699
24 1525 7700 7700-8039 1626.5 25700 25700-26039
25 1930 8040 8040-8689 1850 26040 26040-26689
26 859 8690 8690-9039 814 26690 26690-27039
27 852 9040 9040-9209 807 27040 27040-27209
28 758 9210 9210-9659 703 27210 27210-27659
292 717 9660 9660-9769 N/A
31 462.5 9870 9870-9919 452.5 27760 27760-27809
33 1900 36000 36000-36199 1900 36000 36000-36199
34 2010 36200 36200-36349 2010 36200 36200-36349
35 1850 36350 36350-36949 1850 36350 36350-36949
36 1930 36950 36950-37549 1930 36950 36950-37549
37 1910 37550 37550-37749 1910 37550 37550-37749
38 2570 37750 37750-38249 2570 37750 37750-38249
39 1880 38250 38250-38649 1880 38250 38250-38649
40 2300 38650 38650-39649 2300 38650 38650-39649
41 2496 39650 39650-41589 2496 39650 39650-41589
42 3400 41590 41590-43589 3400 41590 41590-43589
43 3600 43590 43590-45589 3600 43590 43590-45589
44 703 45590 45590-46589 703 45590 45590-46589

Ref: ETSI TS 136 521-1 V11.2.0 (2013-10)