Airtel 4g white wifi dongle have defect. They powers off after 1-2 hours. After days of follow up. they would replace your dongle with another used/old dongle which would have same issue.
Don’t buy Airtel 4g wifi dongle.
UPDATE:
Airtel representative visited again and this time he replaced that white wifi dongle with the black wifi Hotspot, which have a battery. This seems to be working fine. I am happy that Airtel cared and fixed the issue. So you can go for the black wifi hotspot, but NOT the white wifi dongle.
UPDATE 2:
4g speed(around 20mbps) is useful only if you want to download big files like movies etc. For normal browsing, it’s of no use. You won’t find any difference in 4g and 3g for normal browsing as websites response time is not that fast.