2G/3G Network Issue

[dexcmj]

Hi friends. I am facing some problem of Sony Xperia J, I am using U Mobile which have data plan. When I on my data, it shows H. Well, that is good. But some times, it jumps to G, pretty bad connection. But the issue is, i found out there is some problem. Whenever it shows me G when I on the data, then I try to restart my phone. After that I switch on my data again, it appears H again! I repeated for few times when I get a G while I on data. What happen to my phone? And some of the time data is not on, but there is pop-up of 'No connetion is available, data roaming is off', then suddenly my network signal turned 'R'. What does R means? I cannot make phone calls or sms when the signal is R. But same as well, after I restarted my phone, it is normal again. What happen to my Sony Xperia J? Hope there will be some solutions from you all. Thanks!

[Johan]

It's seems that you drop connection from time to time, or at least it switches between different networks and protocols. When you restart the phone it will search for the best available network automatically. The R icon indicates Roaming, which means you not any longer within your operators network. This whole thing sounds to me as an operator network issue. It could be due to your location or SIM card so I suggest that you try using another SIM in the phone and contact the network operator to check why you're being tossed between different networks.

[axes23]

Please reply me realy soon or othrwise i need to go to the service centre now, i have a data plan from my netwrk provider for 3g data, now whn i insrted sim card in xperia it E on the is this refers to 2g network or 3g netwok how can i manualy switch between 2g 3g because it wuold be real help in saving data and battry too