Ok it seems many do not know about the profile and prl in the phones .if this is not kept updated you will suffer connection problems.

For android it can be found in the settings section in system updates .it's best do do this twice a month .I do not know if tabs have it but I think all devices do .

The prl is the signal strength for you phone (I.e) your devices ability to send and receive data and speed at witch it's received and sent .this should be checked once a month .

Hope this helps.some of you.