AN_1106_SRM_LTE_TDD 2 / 6 Subject to change
1 The LTE E-UTRA frequency bands
LTE stands for Long Term Evolution. This is the fourth generation of mobile telecommunications networks, called 4G
for short. The specification process for LTE began in around 2004, and it took another five years or so until the first
LTE networks came on line between 2008 and 2010. LTE is now operational almost everywhere in the world, and has
already developed further to LTE Advanced, or 4.5G. It is likely that LTE will also play an important part in the coming
decades, particularly in connection with the fifth generation mobile telecommunications standard (5G).
The LTE frequencies are based on the E-UTRA specification, which stipulates frequency bands between 700 MHz
and 3700 MHz. (E-UTRA band 46 is actually at 5200 MHz, but is not used according to information available when
this article was written.) Some E-UTRA bands are listed in Table 1 along with their frequency and duplex information.
E-UTRA band Frequency band
[MHz] Frequency range [MHz] Duplex mode
1 2100 UL: 1920 – 1980 DL: 2110 – 2170 FDD
3 1800 UL: 1850 – 1910 DL: 1930 – 1990 FDD
7 2600 UL: 2500 – 2570 DL: 2620 – 2690 FDD
12 700 UL: 699 – 716 DL: 729 – 746 FDD
30 2300 UL: 2305 – 2315 DL: 2350 – 2360 FDD
33 2100 1900 – 1920 TDD
38 2600 2570 – 2620 TDD
40 2300 2300 – 2400 TDD
42 3500 3400 – 3600 TDD
44 700 703 – 803 TDD
65 2100 UL: 1920 – 2010 DL: 2110 – 2200 FDD
Table 1 makes it clear that some frequency bands definitely overlap. This basically means an increase in spectrum
management, particularly in frontier regions, and there is a risk of interference. For example, bands 12 and 44 have
spectral components in common, as do bands 30 and 40. Table 1 also shows that each LTE frequency band is
allotted one of two specific duplex modes: either frequency division duplex (FDD) or time division duplex (TDD). (A
look at all the E-UTRA bands shows that bands 1 through 32 and 65 through 71 only allow FDD, while bands 33
through 46 only allow TDD.) The duplex mode describes the dimension in which the uplink and downlink are
separated from each other. This is described in detail below.
At the time this article was published, the majority of LTE networks worldwide used FDD mode. According to the
Global Mobile Suppliers Association (GSA) there were 95 LTE TDD networks in 54 countries worldwide in operation
at the end of January 2017. At that time, there were 32 network providers operating both LTE FDD and TDD
networks. TDD networks are frequently found in China and India, but also in Canada, the USA, and some African
countries, particularly Ghana and Nigeria. LTE in Europe mainly uses FDD mode, but TDD networks do exist in
Belgium, Finland, Ireland, Italy, The Netherlands, Sweden, Slovakia, Spain, and Russia.
Table 1: E
