Cell PhoneMobile communication is through devices that are not connected by cables. The transmission medium is the air, and the message is sent by means of electromagnetic waves. Mobile phone which is a wireless electronic device that is used to access and use the services of the mobile network is used for communication. Cellphone in the majority of Latin American countries is also called since the service works through a network of cells, where each Repeater antenna signal is a single cell, although there are also mobile telephone networks.
Mobile is basically consists of two major parts: a network of communications and terminals that allow access to the network.
The mobile phone today has become a very useful instrument because of the easy communication between people. The devices have different applications that can provide various daily tasks.

From the 21st century, mobile phones have acquired capabilities above and beyond will be limited only to call, translate or send text messages, it can be said that it has incorporated the functions of devices such as PDA, camera, video camera, Call Cell Phones portable game console, electronic calendar, alarm clock, calculator, micro-proyector, portable radio, GPS or Media Player (to the point of causing the obsolescence of many of them) as well as to perform a multitude of actions on a small, portable device that practically all the inhabitants of developed countries and a growing number of people in developing countries. This kind of evolution of the mobile phone is known as smart phone (or phone automaton).
At the end of the 50s of the 20th century the Soviet scientist Leonid Ivanovich Kupriyanovich develops a mobile communication system that culminates in the KL-1 model that uses radio waves and is able to reach a distance of 30 km and can serve multiple clients. This mobile phone was patented on January 11, 1957 with the certificate of Patent No. 115494. It is was the basis for the research that Leonid Ivanovich Kupriyanovich began the following year at the Institute of scientific research of Voronezh. Emerged from this research and development the “Altay” which was distributed commercially in 1963 becoming present in more than 114 cities of the Soviet Union, giving service to hospitals and doctors. The system was extended by other countries in Eastern Europe like Bulgaria who would show it in the international exhibition Inforga.1
The first automatic commercial network was that of NTT of Japan in 1974 and followed by the NMT, running simultaneously in Sweden, Denmark, Norway and Finland in 1981 using phones from Ericsson and Mobira (the ancestor of Nokia). Saudi Arabia also used the NMT and put in operation one month earlier than the Nordic countries. The first antecedent to the mobile phone in United States is Motorola company, with its model DynaTAC 8000 X.

The model was designed by the engineer of Motorola Rudy Krolopp in 1983. Model weighed a little less than a kilo and had a value of almost 4000 U.S. dollars. Krolopp would subsequently be incorporated to the team’s research and development of Motorola led by Martin Cooper. Both Cooper and Krolopp appear as owners of the original patent. A splitting of the DynaTAC 8000 X, Motorola would develop new models such as the Motorola MicroTAC, released in 1989, and the Motorola StarTAC, released in 1996. Basically we can distinguish two types of mobile networks on the planet, the existence of these is essential so that we can carry out our cell phone use, so we browse on the Internet or so we send text messages as do usually. The first network is analogue type (TMA) mobile telephony network, it establishes communication by means of analog voice signals, both in the radio section and in the ground segment; the first version of it ran in the radio of the 450 MHz band, then it would work in the band of 900 MHz, in countries such as Spain, this network was withdrawn on December 31, 2003. Then we have the digital mobile telephone network, here now the communication is carried out by means of digital signals, this allows us to optimize the use of the bands of radio frequency as the quality of the transmission of the signals. The most significant exponent this network currently has is GSM and UMTS third generation, both operating in the bands of 850/900 MHz, in 2004, reached the 100 million users.

Martin Cooper was the pioneer in this technology, considered him as “the father of the cell phone” to introduce the first radio, in 1973, in the United States, while working for Motorola; but it was not until 1979 when the first commercial systems appeared in Tokyo, Japan NTT company.

Mobile phone with multimedia keys.
In 1981, the Nordic countries introduced a cellular system similar to AMPS (Advanced Mobile Phone System). On the other hand, in the United States, thanks to the fact that the governing body of that country adopted rules for the creation of a commercial cell phone service, in 1983 was in operation the first commercial system in the city of Chicago.

Evolution technology and design of cellular or mobile phones from 1995 until 2001.
With this starting point, the cellular phone as an alternative to the conventional wireless has spread in several countries. Technology had great acceptance, so a few years establish itself began to saturate the service. In that sense, there was the need to develop and implement other forms of multiple access to the channel and transform analog systems to digital, in order to accommodate more users. To separate one stage on the other, the cell phone has been characterized by having different generations. Then describes each of them. Touch mobile phones today have great importance.
Unlocked Cell Phones