Have you ever see a person without a mobile phone in his or her hand/pocket? The mobile phones are also called a wireless phone or cellular devices. Mobile is a short-range, it is handy . Mobile phone is also portable electronic device used for mobile voice or data communication. The history of mobile phones started in 1915 American Telephone & Telegraph discussed developing a wireless phone, but they were also afraid of the fact that deployment of the technology could undermine its monopoly on wired service in the U.S.

The first commercial mobile phone service was launched in Japan in 1978.The first mobile phone to enable internet connectivity and wireless email, the Nokia Communicator, was released in 1996, creating a new category of expensive phones called smart phones. In 1999 the first mobile phone internet service was launched by NTT Do Como in Japan under the I-Mode service. Now a days mobile phones are not only used for voice or data communications but also support many additional services, and accessories, such as SMS for text messaging, email, packet switching for access to the Internet, gaming, Bluetooth, infrared, camera with video recorder and MMS for sending and receiving photos and video.

Mobile phones transmit and receive phone calls directly via radio waves. The calls picked up and sent on from a local aerial. Since 1990’s, mobile phones have become hugely popular worldwide. Mobile phones connect with small transmitter-receivers that each control an area, or ‘cell’. As a person moves from one cell to the next, the mobile phone switches the signal it receives to the new cell.Mobile phone services has expanded considerably more quickly than land telephone services.

Although telephone lines have existed in the major cities since the late 1970s, service was expensive and inadequate and was often cut off for no apparent reason. Use of cellular phones, on the other hand, has spread steadily since the late 1990s. Internet service began to expand rapidly at the beginning of the 21st century.There are many number of big multinational companies manufacturing many mobile phone in different models under different mobile phone brand names.

Nokia is currently the world's largest manufacturer of mobile phones, with a global device market share of approximately 40% in 2008. Other major mobile phone manufacturers (in order of market share) include Samsung (14%), Motorola (14%), Sony Ericsson (9%) and LG (7%). These manufacturers account for over 80% of all mobile phones sold and produce phones for sale in most countries.Other manufacturers include Apple Inc., Audiovox (now UTStarcom), Benefon, BenQ-Siemens, CECT, High Tech Computer Corporation (HTC), Fujitsu, Kyocera, Mitsubishi Electric, NEC, Neonode, Panasonic (Matsushita Electric), Pantech Curitel, Philips, Research In Motion, Sagem, Sanyo, Sharp, Siemens, Sierra Wireless, SK Teletech, Sonim Technologies, T&A Alcatel, Huawei, Trium and Toshiba. There are also specialist communication systems related to (but distinct from) mobile phones.Many people prefer PDA’s which is a smaller version of computers made in the form of mobile phones.

Mobile phones generally obtain power from batteries which can be recharged from a USB port or from mains power or a cigarette lighter socket in a car using an adapter (often called battery charger ). Formerly, the most common form of mobile phone batteries were nickel metal-hydride, as they have a low size and weight. Lithium-Ion batteries are sometimes used, as they are lighter and do not have the voltage depression that nickel metal-hydride batteries do. Many mobile phone manufacturers have now switched to using lithium-Polymer batteries as opposed to the older Lithium-Ion, the main advantages of this being even lower weight and the possibility to make the battery a shape other than strict cuboids.

Mobile phone manufacturers have been experimenting with alternate power sources, including solar cells.In addition to the battery, most mobile phones require a small microchip, called a Subscriber Identity Module or SIM Card, to function. Approximately the size of a one-cent postage stamp, the SIM Card is usually placed underneath the battery in the rear of the unit.Mobile phone is a very essential device without which a person who could not live without in this present century. There would not be a person who walk down a street without a mobile phone in his hand.