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LTE frequency bands

FDD and TDD LTE frequency bands

FDD spectrum requires pair bands, one of the uplink and one for the downlink, and TDD requires a single band as uplink and downlink are on the same frequency but time separated. As a result, there are different LTE band allocations for TDD and FDD. In some cases these bands may overlap, and it is therefore feasible, although unlikely that both TDD and FDD transmissions could be present on a particular LTE frequency band.
The greater likelihood is that a single UE or mobile will need to detect whether a TDD or FDD transmission should be made on a given band. UEs that roam may encounter both types on the same band. They will therefore need to detect what type of transmission is being made on that particular LTE band in its current location.
The different LTE frequency allocations or LTE frequency bands are allocated numbers. Currently the LTE bands between 1 & 22 are for paired spectrum, i.e. FDD, and LTE bands between 33 & 41 are for unpaired spectrum, i.e. TDD.

FDD LTE frequency band allocations

There is a large number of allocations or radio spectrum that has been reserved for FDD, frequency division duplex, LTE use.
The FDD LTE frequency bands are paired to allow simultaneous transmission on two frequencies. The bands also have a sufficient separation to enable the transmitted signals not to unduly impair the receiver performance. If the signals are too close then the receiver may be "blocked" and the sensitivity impaired. The separation must be sufficient to enable the roll-off of the antenna filtering to give sufficient attenuation of the transmitted signal within the receive band.

FDD LTE BANDS & FREQUENCIES
LTE BAND
NUMBER
UPLINK
(MHZ)
DOWNLINK
(MHZ)
WIDTH OF BAND (MHZ)DUPLEX SPACING (MHZ)BAND GAP (MHZ)
11920 - 19802110 - 217060190130
21850 - 19101930 - 1990608020
31710 - 17851805 -1880759520
41710 - 17552110 - 215545400355
5824 - 849869 - 894254520
6830 - 840875 - 885103525
72500 - 25702620 - 26907012050
8880 - 915925 - 960354510
91749.9 - 1784.91844.9 - 1879.9359560
101710 - 17702110 - 217060400340
111427.9 - 1452.91475.9 - 1500.9204828
12698 - 716728 - 746183012
13777 - 787746 - 75610-3141
14788 - 798758 - 76810-3040
151900 - 19202600 - 262020700680
162010 - 20252585 - 260015575560
17704 - 716734 - 746123018
18815 - 830860 - 875154530
19830 - 845875 - 890154530
20832 - 862791 - 82130-4171
211447.9 - 1462.91495.5 - 1510.9154833
223410 - 35003510 - 36009010010
232000 - 20202180 - 220020180160
241625.5 - 1660.51525 - 155934-101.5135.5
251850 - 19151930 - 1995658015
26814 - 849859 - 89430 / 4010
27807 - 824852 - 869174528
28703 - 748758 - 803455510
29n/a717 - 72811
302305 - 23152350 - 2360104535
31452.5 - 457.5462.5 - 467.55105

TDD LTE frequency band allocations

With the interest in TDD LTE, there are several unpaired frequency allocations that are being prepared for LTR TDD use. The TDD LTE bands are unpaired because the uplink and downlink share the same frequency, being time multiplexed.

TDD LTE BANDS & FREQUENCIES
LTE BAND
NUMBER
ALLOCATION (MHZ)WIDTH OF BAND (MHZ)
331900 - 192020
342010 - 202515
351850 - 191060
361930 - 199060
371910 - 193020
382570 - 262050
391880 - 192040
402300 - 2400100
412496 - 2690194
423400 - 3600200
433600 - 3800200
44703 - 803100
There are regular additions to the LTE frequency bands / LTE spectrum allocations as a result of negotiations at the ITU regulatory meetings. These LTE allocations are resulting in part from the digital dividend, and also from the pressure caused by the ever growing need for mobile communications. Many of the new LTE spectrum allocations are relatively small, often 10 - 20MHz in bandwidth, and this is a cause for concern. With LTE-Advanced needing bandwidths of 100 MHz, channel aggregation over a wide set of frequencies many be needed, and this has been recognised as a significant technological problem.