Originally Posted by
Prasun Banerjee my solution still is to switch off data connection and switch it back on ... dont know why but still suspect its a carrier specific problem !!!
Not sure I agree. Turning data on/off has nothing to do with the carrier. That is a totally an internal thing as with reboots etc. Providing the carrier signal is emitting from the tower that is all the carrier is concerned about. How that signal is deciphered and used is up to the phone. If the little "3G" or "4G" icon was going on and off then I may be convinced that there could be an issue with the carrier.
But - I have two phones, a Moto X and the 520 and and neither show that icon differently at any time. If there is an issue with the 3/4G then both phones will show it. I have seen that probably twice in the past six months and only for minutes duration even then.
Turning data off and on again probably resets the QoS process. It sounds like the same issue I have sometimes with the Moto X. Android is hopeless at QoS. I now have 4.4.3 and it is still no better, so I have to use the 520 for Tethering at home as wp8.0 is excellent at the QoS.