Is iPhone5 4G compatible ?

India's largest Network Provider Airtel has just started 4G in New Delhi, India.

I own a iPhone5 with iOS 8.1.3, which has only 2G, 3G and LTE options, for Voice & Data, in Cellular Data Settings.

Will this work with 4G network ? I have been given a new 4G SIM Card by neighborhood vendor, however the rates

for using 4G network are the same as 3G right now. After one day of trying the new network here,

iPhone5 does give better speeds after changing to 4G SIM Card, but the iPhone5 still shows Airtel 3G on the top bar

of the screen.Therefore, I am not sure whether I am on 4G, with the iPhone5.