Hello friends iam using airtel sim at the begining it gives very fast speed network thaan other operator and after few days it gets very poor in network and if I call to anyone it get a while to make a call and I has to keep that number because it linked with my bank details and iam having more contact in it so I cant be able to change the sim so please improve your network thank ypu for reading my review I hope it will the reason for many of them