MOBILE PHONES HISTORY
The picture at the right was taken at a square in the center of Skopje, the capital of Macedonia. The sculpture symbolizes the modern life with the Mobile Phone that accompanies almost every person in the world.
MOBILE PHONES BEFORE THE CELLULAR NETWORKS
Before the cellular telephone systems, full duplex mobile telephones operated in cars in the USA. It started in 1946 with two systems: The Highway System and the Urban System. The Highway System operated on the Low VHF band (Transmit - 43 MHz, Receive 35 MHz). The Urban System operated on the High VHF band (Transmit - 158 MHz, Receive 152 Mhz). The Duplex FM mobile radios included 6 and 12 channel Selective Calling units. Later on MTS and IMTS systems were used until the 1990's
Bell Telephone developed in the 1960's a new mobile telephone system the IMTS - Improved Mobile Telephone Service.
In 1964, Motorola introduced a new impoved IMTS mobile telephone with push button control panel weighing half of the trunk moiunted types of the 1940's and 1950's.
MOTORLA IMTS Mobile Telephone
The first portable Full Duplex Cellular Telephone was designed and produced by MOTOROLA in 1983. It was the Dyna Tac 8000X.
It Weighed less than 1 kg, with a battery capacity of about one hour between chargings and a 30 numbers memory. The display was a LED type and the flexioble antenna was 15 cms long.
Despite the high price tag of $3,995, 300,000 Dyana TAC 8000X cellular phones were sold aorond the world until the end of 984.
The Cellular Netwok Structure
The area covered by the Cellular Network is divided into Cell Areas. Each cell is split into three hexagon shaped sectors. The texture of the entire Cellular Network area looks like a beehive. The radio equipment is installed at the center of each cell and the antennas are directed towards the three sectors of the cell area.
At the center of each cell a computerized base station transmits and receives at the 900 MHz or 1,800 MHz band. The covered area at each sector is influenced by the topographic and other area conditions. When a cellular telephone is operated, the Cellular Switching System determines which cell will be used and selects a free channel to conduct the communication. When a cellular telephone is traveling along a long route, the system shifts the communication from the base station of the first cell to the base station of the next cell.
The first cellular networks in the USA used the analog AMPRS system at the 800 MHz band. It was replaced later on with new digital CDMA and D-CDMA systems and later on the GSM system. The first cellular systems in northern Europe operated with the NMT-450 system on the 450 MHz band. It was replaced by the TACS system on the 900 MHZ band and later on the GSM system operating on the 900 MHZ and 1,800 MHz bands.
The old mobile telephone systems required high transmitting power at the base stations and the mobile phones to cover large areas. The structure of the cellular phone system needs low transmitting power at the base stations and the mobile phones. In addition, the operation on the higher UHF bands enabled more channels and wider band capability. The new mobile phones became smaller, the operating time between chargings was reduced, the memory capacity was increased and many applications have been added, like: Calculator, Diary, Games, Internet, Still and Video Camera. More manufacturers joined the race and the prices were reduced. The cellular telephones of NOKIA and Ericsson dominated the market for many years.
The Generations of Cellular Networks
1G – The first generation analog networks operated with an analog system that was developed by NTT in Japan. In northern Europe the NMT system was in use and the AMPRS system operated in the USA.
2G – The second generation digital networks started at the 1990’s. The GSM system was developed and operated in Europe and the CDMA system was developed and put to work in the USA.
3G – The number of cellular mobile phone users was increased dramatically. The increased demand for transmission of huge quantities of information, data, internet surfing and images, brought to the development of the third generation networks.
4G – More bandwidth is required to respond to the demand of Smart Phone users for higher rates and the increased variety of applications. The first fourth generation network in the USA is the WiMAX and in the Scandinavian countries, the LTE network was introduced.
Mobile Phones Evolution
Dyna TAC 8000X
MOTOROLA Micro TAC
MOTOROLA 3200 1st 2G
Treo 700W 1st Palm Phone
NOKIA 9000 Communicator
Apple First iPhone
The iPhone revolution of 2007 changed entirely the structure of the mobile phones. A touch panel display replaced the QWURTY keyboard and an Auto-Rotate sensor was added. From now on the mobile phone became a Smart Phone that acts as a handheld computer with connectivity to the cellular, Wi-Fi and Bluetooth networks.
This chapter started with the description of the 1950’s mobile telephone, in which the radio equipment was mounted in the car trunk and the telephone handset in the car cabin. In our days, the new cars include Bluetooth interface that integrates the mobile phone with the car’s computerized entertainment system.
The Cellular Phones Collection at the VIRTUAL MUSEUM shows examples of popular types that were used before the Smart Phone Era.
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