Whats is 4G LTE?
Long Term Evolution (LTE) is marketed as the 4G LTE which is a communication standard much like we have the 3G. 4G is capable of even higher data speeds compared to the 3G standard for mobile data communication.
Nokia Lumia 920 supports a total of 9 LTE Bands, highest so far in any phone available in the market. The supported bands are 700 / 800 / 850 / 900 / 1700 / 1800 / 1900 / 2100 / 2600. On the other hand, Apple iPhone 5 only supports 5 LTE Bands which are 700 / 850 / 1800 / 1900 / 2100.
Now, the irony in India is that out of all the 9 bands, Airtel, the only 4G operator uses 2300 MHz band which is not supported by both the popular phones. The most efficient band in the LTE spectrum is the 700 MHz band. This band is yet to be auctioned and hence, will be available in a couple of years.
Hence, with Nokia Lumia 920, you will not be able to immediately access the 4G services, however, there may be other operators that use one of the supported bands in future. I wonder what made Nokia drop the only supported band in India when it considered such a wide range of LTE Bands. The only reason that I can think of it that this phone targets the entire world and India often uses something that is not used anywhere in the world.