Call Drops - Airtel issue. Set to 2G only - not an issue on vodafone.

I have had a set of Call failures on Airtel number, these have been happening and I decided to check some details.

Call Failure on Airtel, Sigh! :

Voice coverage on old Operators(Vodafone, Idea, Airtel) is better in 2G than on 3G or 4G towers. So decided to force 2G as preferred on Iphone 5s for airtel sim. Checked settings and there is no option which allows 2G on a Airtel sim. see screenshot 2:

No option to select 2G on Airtel, why ?:

Now checking the same setting on Vodafone sim this allows setting 2G as preferred sim on iPhone 5s.
And there I have no call drops when Vodafone sim is used.



See the full signal when Vodafone 2G is selected and that just works. No call drop on my secondary number.


Now decided to reach Airtel on all of this, But they aren't able to understand the issue. Reached them on twitter - they checked and still not able to root cause or provide the solution.

For now I will just use Vodafone as a temporary secondary sim.