If you're suffering from low or fluctuating signal strength and poor reception resulting in dropped calls on your iPhone, you're not alone. Many iPhone users have been complaining of this problem, leading to a frustrating experience for iPhone owners. Fortunately, there are a number of tricks you can do to boost the signal strength of your iPhone.
Sometimes boosting the signal strength of an iPhone is as simple as resetting the network settings. To do this, go into "Settings," then touch "General," then "Reset," then "Reset Network Settings." Once the network settings have been reset and your iPhone restarted, any stored Wi-Fi passwords will be deleted and restored to the network settings.
Additionally, sometimes restoring the iPhone to its factory settings will help resolve signal strength issues. However, keep in mind that this will delete text messages, contact favorites, call history, widget settings and sound settings.
Remove SIM Card
If the SIM card of your iPhone is not in place properly, the signal strength can be poor. Try removing the phone's SIM card by pushing the end of a paper clip into the small hole located at the top of the phone. The SIM tray will pop open. Remove the SIM card from its slot and blow gently into the slot or use compressed air to remove any dirt or debris. Then re-insert the SIM card into the tray.
Keeping with the idea that if the SIM card is not in proper place, the phone will get poor signal strength, scotch tape placed on the SIM card has proven to be effective for boosting signal strength. The iPhone's SIM card tray doesn't seem to fit the SIM card very well, resulting in poor signal strength. To remedy this, attach a small piece of scotch tape to the blank side of the SIM. The tape will bulk up the SIM card enough to ensure a snug fit in the SIM tray, helping to increase the signal strength of the iPhone.
Dock iPhone or Attach to USB Cable
Docking an iPhone or attaching it with a USB cable to a computer can result in a boost of signal strength. However, this is thought to be because of a boost in charge to the battery.
Magnetic Carrying Case
IPhones may experience a drop in signal strength and interference when placed in a carrying case with magnetic clips. To remedy this, remove the iPhone from the carrying case. Turn the phone off and then on again. Press and hold the "Sleep/Wake" button–located on top of the phone–until a red slider appears. Press and hold the "Sleep/Wake" button again until the Apple logo appears. If the issue persists, you will have to contact AppleCare for service.
If none of the above options have helped to improve signal strength on your iPhone, the last option you can try is to buy a signal booster. Signal boosters will almost always remedy the problem; however, they can be quite expensive.
Keep in mind that any or all of these tricks and fixes may or may not void the iPhone's warranty.