Mobile Phones

Many years ago...


two-way radios were used in vehicles such as taxicabs, police cruisers, ambulances for a faster communication, but were not mobile phones because they were not normally connected to the telephone network. Users could not dial phone numbers from their mobile radios in their vehicles. During the early 1940s, Motorola developed a backpacked two-way radio, the Walkie-Talkie and later developed a large hand-held two-way radio for the US military.

In 1947, Douglas H. Ring and W. Rae Young proposed hexagonal cells for mobile phones. Philip T. Porter 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 first fully automatic mobile phone system, called MTA (Mobile Telephone system A), was developed by Ericsson and commercially released in Sweden in 1956. This was the first system that didn't require any kind of manual control, but had the disadvantage of a phone weight of 40 kg. MTB, an upgraded version with transistors, weighing 9 kg, was introduced in 1965.
In 1967, each mobile phone had to stay within the cell area serviced by one base station throughout the phone call. This did not provide continuity of automatic telephone service to mobile phones moving through several cell areas. In 1970 Amos E. Joel, Jr. invented an automatic "call handoff" system to allow mobile phones to move through several cell areas during a single conversation without loss of conversation.

FIRST GENERATION MOBILE PHONES (1G)
The first commercial launch of cellular telecoms was launched in 1979. In 1981 the NMT system was launched in Denmark, Finland, Norway and Sweden. This was the first mobile phone technology that allowed international use of the mobile phone or so-called "roaming".

SECOND GENERATION MOBILE PHONES (2G)
The first pre-commercial digital cellular phone call was made in the Unites States in 1990, in 1991 the first GSM network opened in Finland. 2G phone systems were characterized by digital circuit switched transmission and the introduction of advanced and fast phone to network signaling.

THIRD GENERATION MOBILE PHONES (3G)
Not long after the introduction of 2G networks, projects began to develop third generation (3G) systems. Inevitably there were many different standards with different contenders pushing their own technologies. Quite differently from 2G systems, however, the meaning of 3G has been standardized in the IMT-2000 standardization processing.

My opinion

I think that mobile phones are very important to communicate for example if you have broken a leg or just to say "mum, take me at the school, please". With a cell phone you can save lifes and you can talk with people you can never see. Many people use the portable phones to work. But like all the things, the mobile phones have an other side, "a bad side". Some people are addict to the cell phones and they can´t live without them. They are always using the phones, and I believe that is bad to be dominated by a piece of plastic! They depend everyday of the calls they receive or they make. In this respect life many years ago, without mobile phones, was better.
I have a lot of friends that always says "my cell phone is an essential item. I send text messages the whole day", and I can´t believe it!
I think that many times portable phones destroy great moments.

This is my research and my opinion about mobile phones.

Santi