Along with the increased functions and performances, cellular phones have become a portable data processing center offering everything from data management, personal schedule arrangement to entertainment. A cell phone is not only capable of communicating by voices but also capable of transmitting messages, so the cellular phone users may choose to send messages instead of speaking on the phone. There are many cutting-edge functions available nowadays. Accompanying their ever advanced functions, the cellular phones are finding diversifying applications, such as a data (packet) communication terminal for carrying out electronic mails, chatting and internet browsing, that have evolved from module of speech, a database for the management of classified telephone directory and personal schedule data, as well as a game device and a simple digital camera. The digital camera added as a feature on cellular telephones allows users to communicate and exchange information through pictures. Further, personal digital assistant interfaces have been added on some cellular telephone devices, which allow cellular telephone users to access the web, answer e-mail, and organize appointments. In addition to infrared ray transmission, internet connection is also provided on cellular phones so the users can retrieve data or send emails or download graphic data or text from web sites. Cellular phone has become a basic tool in daily life. Cellular phones with data inputting functions have been extensively used for transmission and reception of data and messages over such networks in addition to information processing terminals as personal information managers and portable computers. In general, cellular phones include a timer. A user sets the timer and the cellular phone on which the timer is set performs an alarm function by sounding a terminating signal at a predetermined time. A cellular phone generally is embedded with software called telephone book. The telephone book is comprised of a plurality of addresses stored in its memory. Each address comprises a name of a person and an associated telephone number to contact with. In use, a calling party can select a serial number corresponding to the desired name and telephone number. Once selected, the telephone number is dialed automatically.

A cellular phone is battery-driven electronic communication terminal, which incorporates a battery in a main body to supply operating power needed by an electronic circuit. Typically, the cellular phone can be divided into several groups in accordance with its shape and whether number buttons are exposed to the outside. They include bar type cellular phone having numeral (functional) buttons exposed on the outside, flip type cellular phone whose functional menu buttons are covered by a cover, and a folder type cellular phone whose body is folded in half. The bar type mobile phone is typically structured in that a speaker and a microphone are provided in one case. The transmitter and a telephone receiver are integrated. As more people prefer a smaller sized cell phone, the folder type mobile phone has been more popularized than the other types. The folding portable cellular phone is generally composed of a body and a cover section which is rotatably attached to the body by a hinge, and the body or the cover section is provided with an LCD (liquid crystal display) for displaying necessary information to the user. Some foldable cell phones with a camera function provide a camera section on the outer surface, or on the hinge section. An unfoldable mobile phone has a main display on the front surface, and has a camera section on the rear surface. The user can shoot monitoring picture images on the display while holding the mobile telephone with its longitudinal axis kept horizontally. The latest folder-type design has two liquid crystal displays, one mounted on the inside on an inner surface of a folder and another mounted on the outside on an outer surface of the folder so that a user can conveniently check simple information or status information of the mobile phone through the LCD mounted on the outer surface of the folder without opening the folder. A cellular phone generally comprises a housing, a circuit board installed inside the housing, and an antenna installed at a top end of the housing. As the most popular design, the folded type cellular phones typically include a housing having a main body, a display unit, and a hinge unit. The front cover generally includes the user interface, such as a keypad, microphone, speaker, keypad and display. The main body is provided with a battery, a keypad including such input keys as number buttons, a power button and function buttons, a printed circuit board (PCB) inside for transforming the input signals of the keypad into signals, and a mike in the bottom portion. The display unit is incorporated with a speaker at the top portion and an LCD screen for displaying the data inputted from the keypad of the main body. The hinge unit is used for connecting the main body and the LCD unit and folding and unfolding them smoothly. The PCB of the main body and the LCD screen of the LCD unit are connected by a flexible printed circuit board electrically. The main printed circuit board of the mobile phone mainly includes a first portion corresponding to the keypad module and a second portion corresponding to the LCD module. The main printed circuit board has many different functional units mainly for RF applications. Such units include an antenna connector, a duplexer, a power amplifier, an RF transmitter circuit, an RF receiver circuit, and the baseband circuit.

A typical cellular phone comprises a keyboard and a visual display on its front surface, and a key depression detector and a logic value generator communicating between the keyboard and the display. Generally, a keypad for a mobile phone is an input device consisting of a separate grid of numerical and function keys arranged for efficient data entry. The keys are fitted into holes formed on a front housing of the mobile phones and jutted out so that users can conveniently input the data. Most of cellular phones are designed to have a liquid crystal display device for receiving and transmitting symbol data such as a picture, a letter and other characters, and on which the pixel data having relatively large data quantity, a received incoming signal state, and a remaining battery quantity are displayed. Such cellular phones include a lighting device, usually a back light device, for lighting a liquid crystal display and key pads, which is necessary for a user to read a screen of the liquid crystal display device and correctly select a desired key pad at night or in poor lighting circumstance. The cell phone antenna is an essential component of the mobile phone, and is a crucial factor for determining speech quality. The antennas serve to improve transmission and reception sensitivity of the portable communication terminals. An antenna radiates electromagnetic waves with a power that is a function of its electric feed signal's power and frequency. In general, portable communication terminals comprise various shapes of antennas. In general, an antenna is an electronic combination of a helical antenna and a whip antenna. When the mobile phone is in signal waiting state or the mobile phone's radio environment is favorable, only the helical antenna operates. On the other hand, when the mobile phone is used for conversation or the mobile phone's radio environment is poor, both the helical antenna and the whip antenna are operational. The helical antenna has a relatively large volume and is generally affixed on the top end of the mobile phone. Most cellular phones are equipped with rechargeable batteries which can be recharged through a connection terminal at the rear of the battery in a state that the battery is only inserted into the battery charger or the cellular phone having the battery is inserted into the battery charger. A charging circuit among the peripheral accessories is generally incorporated into a cellular phone main body and is recharged only when connected to an external power source via a connector. The battery of a mobile phone is typically a flat type which attaches retractably to the bottom side of the phone, fitting into a recess that has been formed for it.

Generally, a cellular phone is a mobile terminal through which a mobile communication service is provided within a predetermined service area where a portion of subscriber lines regionally fixed is wireless. Cellular telecommunications systems are characterized by a plurality of mobile units (e.g. cellular phones) in communication with one or more base stations. Standard cellular communication networks are generally divided into geographic cells. Each base station covers a cell within which a mobile unit may communicate. A cell covers a limited geographic area and routes calls from mobile units to and from a telecommunications network via a mobile switching center. Signals transmitted by the mobile units are received by a base station and often relayed to a mobile switching center (MSC). Base transceiver station hardware is deployed near each antenna to communicate with mobile stations in that cell. The mobile phone terminal assumes all radio and transmission functions and a subscriber identity module (SIM) associated with it. The SIM card operates to identify the subscriber to the network. Most SIM's are in the form of a chip card that establishes the subscriber relationship with the mobile phone system operator. The SIM card contains the mobile subscriber identification (IMSI), the secret individual subscriber key (Ki) an authentication algorithm (A3), a ciphering key generating algorithm (A8), a personal identification number (PIN) and other permanent and temporary data. The wireless link between the base station and the wireless subscriber unit is defined by one of a plurality of operating standards such as CDMA (code division multiple access), and GSM (global system for mobile communication). These operating standards define the manner in which the wireless link may be allocated, setup, serviced and torn down. There are an emerging number of standards for cellular communication. Recently, third-generation (3G) communication systems have been proposed. 3G mobile communications system will provide an enhanced range of multimedia services (eg video, high speed Internet access). The newest generation of wireless communications systems that allows greater bandwidth and opens the way to increased data-over-wireless solutions.