is rechargeable. In a rechargeable battery, electrical energy from an outside source is applied to a secondary cell, the negative-to-positive electron flow that occurs during discharge is reversed, and the cell's charge is restored. The invention of mobile phones showed science and technology. There was an evolution of mobile phones through years. Before mobile phones were made, there were wired telephones, which weren’t portable. By technology, there was an improvement, wired telephones changed to wireless telephones, which are then changed to mobile phones. The idea of a wireless phone is very creative as it involves science. Firstly, they built mobile phones with outer antenna. However, The wireless phones now are built with inner antennas. For instance, if someone is talking on the phone, the phone converts the voice into electrical signal, which is then transmitted as radio waves that are detected by a receiver in your telephone, where the signals are changed back into the sound of a voice. Furthermore, the mobile phones are portable because of the compact antennas and the small amount of power so that mobile phones could send a signal over a very short range. Portable phones have helped many people to make phone calls in anywhere. They could also reach anyone easily without exerting any effort.
The evolution of mobile phones doesn’t stop. One of the mobile phone services is the text messaging . This service has helped more people communicate via texting and chatting. “The first text message was sent on 3 December 1992”(Arthur). Short Message Service (SMS) is a text messaging service component of phone, web, or mobile communication systems. Also, it has attracted more people to try the new creation in mobile phones. Nevertheless, the technology of mobile phones is continuing to increase as modern mobile phones have a wide variety of services. Modern mobile phones could access Internet. The phone connects to the Internet using the same wireless connection used to make and receive calls. The mobile phone connects to a cell tower in the area where you could access Internet, receive and send data. This way to access Internet is called 3G. In addition, there is another way to access to Internet by mobile, which is Wi-Fi. Wi-Fi is a new technology, which allows devices to have access to Internet. There should be a station between the wifi and the mobile phone. All stations share a single radio frequency communication channel and all stations within range receive transmissions on this channel. Technology is used in tremendous ways to manufacture the most beneficial services.
22