Sunday, March 1, 2015

MOBILE PHONES

·         Mobile phones have become an indispencible part of our lives. Due to the fast growing technology and innovations over a period of time, mobile phones are now affordable to everyone.


·         It was Charles Stevenson who invented radio communication in early 1890s for keeping contacts with the offshore lighthouses.

·         In 1894, Marconi transmitted signals over the distance of 2 km and Fessenden capably broadcasted music through radio by 1906.

·         In 1908, Nathan B. Stubblefield lived in Murray, Kentucky applied for the U.S. Patent 887,357 for a wireless telephone but he originally applied only for radio telephones.

·         The radio telephones were used for air traffic safety as well as in the passenger airplanes. At the time of Second World War, German tanks made great use of these radio telephones too.

·         Two way radios were an ancestor of the mobiles phones. These mobile phones are referred to as 0G mobile phones, or Zero Generation mobile phones.

·         Later these radio phones incorporated cigarette lighter plugs and were called bag phones. They were fixed in the vehicles to be used either as portable two way radios or mobile phones.


·         In 1940s, Motorola came with new developments in mobile phones called as Walkie Talkie. It was large, bulky and battery operated and was used by US military.

·         In 1956, Ericsson Company released the earliest full automatic cellular phone system called MTA in Sweden. It was operated automatically but too much bulky, weighed around 40 kgs. Its lighter version was introduced in 1965. This was known as MTB and used the DTMF signaling.

·         In 1957, Leonid Kupriyanovich developed experimental model of wearable mobile phones in Moscow, operating with the help of base station. He developed the radio phone known as LK-1 whose battery lasted for around 20-30 hours, weighing 3 kg, and worked within the distance of 20 to 30 km from the station.

·         In 1966, another automatic pocket mobile phone was developed in 1966 at Bulgaria called RAT-0.5, phone coordinated with the base station known as RATZ-10.

·         Invention of mobile phones that closely resembles today’s mobile phones is credited to Martin Cooper, employer and researcher of Motorola.  He initially developed cellular phone named Motorola Dynatac in 1973.


·         It was 5 inches width and 9 inches in length, 2.5 pounds in weight having around 30 circuit boards in it. It had recharge time of around 10 hours, talk time of 35 minutes. One could listen, dial and talk on this mobile phone but display screen was still missing.

·         The next major step in mobile phone history was in the mid-eighties with the First Generation (1G) fully automatic cellular networks were introduced.

·         Motorola DynaTac was the first ever mobile phone to be approved by the FCC (Federal Communications Commission) in the USA in 1983.

·         In 1993, the birth of the Second Generation (2G) mobile phones was found in Finland. In the same year, first SMS text messages were sent and that data services began to appear on mobile phones.
·         Mobiles that we use today are 3G mobiles, or Third Generation mobiles, or even more advanced 4G handsets.

·         3G launched was launched in 2001 and allowed operators to enjoy a huge range of advanced services such as video calling and HSPA data transmission.

·         4G became commercially available in the UK in late 2012 and offers superfast connections and similarly speedy downloads.
 
 

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