Presently in INDIA, the 4 G LTE band-40 with a range of frequencies of 2300 to 2400 MHz (TD-LTE) is effective (online) and provided by operators in the Indian Territory. The other LTE band with a frequency of 1800 MHz (FDD-LTE) is also auctioned by the Government of India. But no telecommunications operators give this LTE band. This 100MHz bandwidth of Band-40 seems to be from 2300MHz to 2400MHz but is shared between downlink and uplink transmissions. Downlink relates to transmissions from eNB(i.e. base station) to UE(i.e. mobile user) and uplink pertains to transmissions from UE to eNB.
There are 2 topologies in LTE technology, LTE FDD and, LTE TDD (or TD-LTE). FDD is Frequency division duplex and TDD is time division duplex. In TDD, one frequency will be used at various times, both by uplink and downlink. In FDD, 2 distinct frequencies are assigned to uplink and downlink. Simultaneous transmissions in both uplink and downlink can therefore exist in FDD.
Indian telecom operator offers 4G LTE service
The major telecommunications operators are leading providers of 4g LTE bands in India. Telecom operators are Airtel, Aircel, Reliance Jio Infocom Ltd, and Vodafone. Airtel is the first company to have introduced the LTE service in INDIA. Airtel uses the 2300 MHz TD-LTE band to provide the service. Aircel is the second to provide LTE service in the very same 2300MHz TD-LTE band. Reliance Jio Infocom Ltd will launch 4 G LTE services in both TD-LTE(2300MHz) and FD-LTE(1800MHz) frequency bands. Vodafone also provides Vodafone LTE bands in India in the FDD-LTE frequency band(1800MHz).
As we know, there are different frequency bands backed by the LTE standard for different frequency allocations in different parts of the world. Before buying 4 G LTE phones in INDIA, one really has to know which LTE frequency bands are accessible in INDIA and backed by Indian telecommunications operators. As currently, only the TD-LTE 2300 band is online, one needs to purchase the LTE-phone that supports this band. There are LTE phones that facilitate both of these frequencies. So if you buy these mobile devices, it will support the current TD-LTE band and also will support FDD-LTE once it is accessible.
As the very first mover, Bharti Airtel, ‘s finest telecommunications operator, began offering 4 G LTE service for customers back in 2012. Airtel is now aggressively pushing its 4 G services after a slow start. At the end of 2015, Vodafone India and Idea Cellular began offering their 4 G LTE service in selected Indian cities. Jio’s commercial launch has definitely disturbed the Indian telecommunications sector.
The LTE bands used in India are divided into separate LTE frequency bands. If you are hoping to move to a 4 G network, you must find a suitable 4 G LTE compatible devices. Indian telecommunications operators have been granted a spectrum license to operate 4 G LTE networks over BAND 5 LTE FDD (850 Mhz), BAND 3 LTE FDD (1800 Mhz), BAND 40 LTE TDD (2300 Mhz), and BAND 41 LTE TDD (2500 Mhz). Your best option is to get a mobile phone that claims to support BAND 40 or BAND 3, as most telcos operate under this BAND.
Regular additions are made to the 4 G LTE frequency bands / LTE spectrum allocations as a consequence of negotiations at the ITU regulatory meetings. These LTE allocations are partly due to the digital dividend and also to the pressure created by the ever-increasing need for mobile communications. Several of the new LTE spectrum allocations seem to be relatively tiny, often 10-20MHz in bandwidth, and this is a reason for concern.
With LTE-Advanced use of channel aggregation for using 100 MHz bandwidths, channel aggregation over a wide range of frequencies is required; the availability of adequate spectrum has been recognized as a major technology problem.
The number of bands allocated to be used has expanded as the pressure on the spectrum rises. Due to different regulatory positions in various countries, it was not feasible for all LTE band allocations to be the same throughout the globe. Global allocations have not been feasible.
In some cases, the bands seem to overlap. It is because of the various levels of accessibility around the world, where different countries have allocated frequencies in a different manner now and traditionally. This means that LTE roaming might have had some constraints, as not all handsets or UEs will be able to obtain the same frequencies.
FDD and TDD LTE frequency bands
FDD spectrum includes pair bands, one uplink, and one downlink bands, and TDD necessitates a single band as uplink and downlink would be at the same frequency but time apart. As a consequence, there are various LTE band allocations for both TDD and FDD. In some cases, these bands may coincide and therefore are feasible, even though it is doubtful that both TDD and FDD transmissions might be available on a particular LTE frequency band.
Often a single UE or smartphone device will have to trace whether a TDD or FDD transmission must be created to a given band. The UEs that roam may experience both types in the same band. They would then, therefore, have to detect how many types of transmission are being carried out on that particular LTE band at its current location. Many chipsets being used in modern phones can perform with either FDD or TDD, generally within a specific frequency.
The number of bands assigned for use had expanded as the pressure on the spectrum also increases. Due to different regulatory positions in various countries, it was not necessary for all LTE band allocations to be the same throughout the globe. Global allocations have not been feasible. In some cases, the bands seem to overlap. It is because of the different levels of accessibility around the globe, in which various countries have assigned frequencies differently now and traditionally. This means that LTE roaming may have some restrictions, as not all handsets or UEs will be able to view the same frequencies.