As the wireline telephone, the mobile phone from a loudspeaker, a microphone, an operating unit (keyboard and display) and a controller (usually a microcontroller). In addition, it is a part of radio (broadcast receiver, antenna) and a separate power supply (usually a battery). Generally, to operate a SIM card required (except for emergency numbers) for the identification to the mobile network used.

Like all devices with integrated computer is a mobile phone is not free of software errors. So far, a few mobile phone viruses for Symbian based devices to know the number is expected to rise. Viruses that are able to block cell phones, mostly based on software errors. Hazards exist primarily in the form of malicious programs that are in communications services under false names or output by the so-called Bluejacking, the error in the Bluetooth implementation exploits. It is recommended that Bluetooth on only when needed, or at least invisible to others to make. Unexpected Bluetooth messages should be rejected.

Almost all newer mobile phones include an interpreter for the Java programming language in a Low output (Mobile Information Device Profile, MIDP), but the essential features of Java contains. A growing scene of programmers provides the user with software.

Mobile phones work in Europe today after the GSM standard. They use frequencies around 900 MHz (D-net) or 1800 MHz (E-net). Triband phones can also be at 1900 MHz or 850 MHz operating frequencies that are mainly used in the U.S.. Quadband phones dominate all four frequencies. While the base stations for mobile phones transmitting at 50 watts, come with mobile phones transmit Max. 2 W (D-net) and 1 W (E-Net) from. For the transmission mode is known as GMSK (Gaussian Minimum Shift Keying, an enhanced, optimized version of the FSC) is used.

In the next (third) generation of mobile devices, there are two competing standards, Universal Mobile Telecommunications System UMTS as a development of GSM and CDMA2000, which is based on the particularly in the United States widespread CDMA standard. Both operate at frequencies around 1800 to 1900 MHz, use many small cells and are designed for higher data speeds and higher number of users optimized. Because of the smaller radio cells and due to advanced modulation techniques, the transmission power of mobile phones compared to GSM 0,125-0,25 W can be reduced.