HISTORY OF MOBILE PHONES

History of Mobile Phones:
Although mobile phones have taken over our current society, they have been around for several decades in some form or another. This history of mobile phones chronicles the development of handheld radio telephone technology from two-way radios in vehicles to handheld cellular phones. In the beginning, two-way radios (known as mobile rigs) were used in vehicles such as taxicabs, police cruisers, ambulances, and the like, but were not mobile phones because they were not normally connected to the telephone network.
EARLY YEARS: Douglas H. Ring and W. Rae Young, Bell Labs engineers, proposed hexagonal cells for mobile phones in December 1947. Philip T. Porter, also of Bell Labs, proposed that the cell towers be at the corners of the hexagons rather than the centers and have directional antennas that would transmit/receive in 3 directions into 3 adjacent hexagon cells.The technology did not exist then and the frequencies had not yet been allocated. When Richard H. Frenkiel and Joel S. Engel of Bell Labs developed the electronics cellular technology was undeveloped till the 1960s.
Radio telephony was first used on the first-class passenger trains between Berlin and Hamburg in Europe in 1926. At the same time, radio telephony was introduced on passenger airplanes for air traffic security. Later radio telephony was introduced on a large scale in German tanks during the Second World War.
Recognizable mobile phones with direct dialing have existed at least since the 1950s.
The first automatic mobile phone system, called MTA (Mobile Telephone system A), was developed by Ericsson and was released in sweden commercially in the mid of 1950s. The upgrade version MTB was introduced in 1965 and used DTMF signaling. It had 150 customers in the beginning and 600.
In 1957, the young radio engineer Leonid Kupriyanovich in Moscow, Russia, made the experimental model of wearable automatic mobile phone ("radiophone"), called him as LK-1, with base station. LK-1 has 3 kg weight, 20-30 km operating distance. In 1958, Kupriyanovich made the new experimental "pocket" model of mobile phone. This phone has 0,5 kg weight. To serve more customers, Kupriyanovich proposed the device, named him as correllator. ("Nauka i zhizn", 10, 1958, p.66, "Technika-molodezhi", 2, 1959, 18-19)
In 1958 USSR also started the developing of "Altay" national civil mobile phone service for cars, based on Soviet MRT-1327 standard. The main developers of Altay system were VNIIS (Voronezh Science Research Institute of Communications)and GSPI (State Specialized Project Institute). In 1963 this service started in Moscow and in 1970 Altay service used in USSR for 30 cities. Last upgraded versions of Altay system still in use in some places of Russia as trunking system.
Bulgaria presented the pocket mobile automatic phone RAT-0,5 with base station RATZ-10 (RATC-10) on Interorgtechnika-66 international exhibition in 1966. One base station, connected to one telephone wire line, could to serve 6 customers.
Dr. Martin Cooper of Motorola, made the first US analogue mobile phone call on a larger prototype model in 1973.


Dr. MARTIN COOPER:
On April 3, 1973, Motorola employee Dr. Martin Cooper placed a call to rival Joel Engel, head of research at AT&T's Bell Labs, while walking the streets of New York City talking on the first Motorola DynaTAC prototype in front of reporters. Motorola has a long history of making automotive radio, especially two-way radios for taxicabs and police cruisers.