The biggest and most aggravating problem in the iPhone 4 is a problem with the signal. This problem occurs when the users hold the phone in a particular way. The issue is in the design of the phone and software updates are not meant to fix this problem. The problem is known as antenna gate where the signal strength of the iPhone 4 plummets from strong signal down to nothing when the iPhone is held in a certain way.
The problem is very frustrating for iPhone users who love their device because of its amazing aesthetics. Apple held a press conference in July following the launch of the phone to offer free bumpers to those who were facing the problem.
So if you are facing problems with the signal of an iPhone 4 then software updates will be of no use.
Invest in bumpers to ensure that the signal does not suffer because of the way you hold the phone.