After a hard reset on my Tablet 2 the Range is not consistent while using my mobile network, what could be wrong?

[hkannans]

Range is not consistent while using mobile network

I have hard reset my tab 2. After that the internet is not consistent. The range fully lost while browsing some sites or using WhatsApp Messenger. After some seconds the range come back and no issue in the internet. After some second it lost again. How can I resolve this issue. Please help me.