My xperia sp is 4 month old.i am facing problem with data usage.once i put off data usage then after switching off the phone only i am able to use data usage.without switching off phone i am unable use data.thats why every time i need to switch off and on my phone to use my data.Please suggest me what could be the reason behind this.
Check that you have the correct APN settings, also if your SIM card its older than 1 year you should get a new one, it doesn't hurt to repair your phone
Yep,APN issue,also maybe incompatible SIM Card(old one).Try doing a hard reset.Or use SUS.Also,you can create another Access Point Name by googling your network provider's "Manual APN creation".
