That can be very irritating. Lets work together to figure this out. Lets do some troubleshooting on your phone.
Please try the following:
**Place the phone into airplane mode for a few minutes and then turn it off.
**Update Data Profile: settings > system > system update > update profile > ok
**Reset Network Settings: Dial ##72786# then tap Call.
**Factory Reset the phone (back everything up)
Are you asking about the data profile update? The data profile synchronizes your phone with the network by updating the network access info.
due to the age of your phone something might be going out in it. you can back up your phone and factory reset it like the agent mentioned above..better odds of hopefully fixing it unless its a hardware issue.
you can try doing a cache/partition wipe on the device before attempting the factory reset though in case that fixes it...you can also try booting the phone into safe mode in case there is a rogue app causing this..once in safe mode try connecting to wifi again..if the problem does not repeat then its probably an app or combo of apps not playing nice with each other..if it still continues then you'll need to attempt the cache wipe and worst case the factory reset.