3G Network issues with Xperia C

[Sonuzade]

Hi, m using Xperia c since long time but m facing 3G Network issue since I bought this phone. My airtel/Vodafone Network goes off automatically including Second sim network also when I use internet then after 5-10 minuts it again came back. It shows full network for first sim but Network speed coming I had tried with both the operators saveral times but no issues from that side.... Can any one guid me if is there any Solution for this..??