The O2 is a PDA and mobile phone that comes with a dual processor. If you are an owner of this phone and find that your signal strength isn't good enough, then you can consider using an internal antenna to boost it. This will help you make and receive calls and also help improve the clarity of your calls. This only takes minutes to install and will also help prevent dropped calls.
Buy an internal mobile phone antenna booster (see Resource links). This small metal device fits beneath your phone's battery. It works by increasing the area on your phone that can receive a signal, thus increasing the strength of the reception. As of 2010 these cost about £6.50.
Turn your O2 phone off and pop the battery out.
Remove the sticker adhesive from the back of the antenna booster. The space beneath your battery is flat and will be able to accommodate the booster. Press the booster onto the area beneath the battery. Make sure that it is sitting flush with your phone's surface.
Put the battery back in and turn the phone on. There will be an increase of two or three bars on your phone.