Cellular or mobile phone is a mobile radio terminal transceiver for communication to access a cellular network. It connects to the network through central sorting present in wired core of the cellular network in turn connected to base stations (BTS, Base Transceiver Station). It is very often equipped with three or more radio cells, each capable of different connections with mobile devices in its respective coverage area.
Your phone allows therefore to have available a connection when you are within range of a base station. Especially when there is no physical obstructions or artifacts limiting the spread / propagation of frequencies of electromagnetic radio (eg. buildings / structures).
The availability of service or the presence of cell coverage, and the signal power, is indicated by the well-known field levels and thus depends on the conditions of radio propagation radio signal. The maximum distance in coverage depends on the specifications related to GSM technology, ranging from a few hundred meters up to 35 km, and the type of terrain on which the communication takes place.
These devices in addition to the transceiver, incorporating electronics consists of a data memory, a processor to perform various applications and software to manage these features. The phones can have a microdiffusore integrated music playback, a built-in radio, a chip for Wi-Fi, a USB slot to connect your phone to your PC, camera, and so on.
Mobile phones can have different shapes, including:
A casing, it is a classic telephone with added a flap which generally covers and protects the keyboard or most recently covering the extended keyboard with a compact type.
Clamshell or flip phones that are close in on themselves using a hinge.
A scroll or Slide, are devices that open and close by sliding on itself same two parts of the same through a guide, generally with the opening will make available the keyboard or additional keys that facilitate the writing.
A rotation, are devices that open and close by rotating itself on the same two parts of the same by a pin.
Classic, one-piece monolithic or are phones that do not open and close.
A critical aspect of mobile phones is their energy consumption, very heterogeneous, and the resulting size of the energy capacity of the batteries that power them. In general, the energy consumption of a mobile phone is mainly due to the capabilities of transmission, the processing of the signal prior to its transmission and after its receipt, and finally the power consumption of the display.
The majority of the capacity is used during the transmission, by omni-directionality of the antenna (dipole antenna) of the mobile terminal. With the evolution of mobile phones, batteries have undergone several changes in order to increase capacity. The most modern phones, the so-called Smartphone, require a much higher energy consumption, due to the power of processors and execution of numerous multimedia activities such as games, videos, or photos.
In some cases, manufacturers of mobile phones and smartphones give the possibility to change some operating parameters, some of which can be automated and allow to increase the battery life.
The different cellular phones may use different techniques for interfacing with the user, these can be:
Touch screen where it acts directly on the screen, touch-sensitive buttons and menus on virtual
Keyboard using the physical buttons on the front of the phone, including a numeric keypad
Compact using the numeric keys to enter letters and a number key encoding more than one letter
Extended, it has a button for each letter, even including numbers and symbols.
Touch screen and keyboard, where you use a combination of the two technologies
Along with these main techniques can be implemented some particular functions or shortcuts along the edges of the phone using some physical buttons.