Interesting Facts About Cell Phones
By Roberto Sedycias
Cell phone (telefone celular) is a
wireless, portable, long-range, electronic telephone, which during travel can
seamlessly change antenna connections, from one radio reception cell to another
radio reception cell, without dropping or losing the ongoing call.
Besides the standard voice function of a telephone, latest cell phones (telefone
celular) have features such as SMS for text messages, MMS for multimedia
messages, radio, games, internet connectivity for email, browsing, blogging,
music (MP3) playback, memo recording, built-in cameras and camcorders, ringtones,
personal organizers, Push-to-Talk (PTT), Bluetooth and infrared connectivity,
call registers, streaming video, downloading video, video call, and also serve
as wireless modems for PCs that can be connected to the Internet.
The power in a cell phone (telefone celular) is obtained from rechargeable
batteries, which can be recharged from the mains, a USB port or a cigarette
lighter port in an automobile. Nickel Metal Hydride were the most common types
of batteries, which due to the "memory effect" (the user can recharge only when
the entire battery is drained off) were replaced by Lithium-Ion batteries, which
did not suffer from any memory effect.
Cell phones (telefone celular) came into existence because of the invention of
hexagonal cells in 1947, for the base stations by Bell Labs engineers at AT&T.
This was further developed during the 1960s by Bell Labs. During a call, the
channel frequency could not be changed automatically from one cell (base station
coverage area) to another cell (base station coverage area) as the person
traveled from the area of one cell to the area of another cell. Amos Joel of
Bell Labs invented a breakthrough invention and called it as the `call handoff`
by which the channel frequency could be changed automatically from one cell to
another cell, during the same call, as the mobile user traveled from one cell to
another cell. Due to their heavy construction, these phones were used mainly in
The first practical cell phone in a non-vehicle setting, and which could be
handheld, was invented by Martin Cooper, the General Manager (Communications
Division) of Motorola, who made the world`s first handheld cell phone (telefone
celular) call on April 3, 1973.
The technology by which the cell phone (telefone celular) works depends on the
mobile phone operator; however, all of them use electromagnetic radio waves,
which are in touch with a cell site (base station). The base station is composed
of several antennas which are mounted on a pole, tower, or building. Cell sites
are spread at a distance of 5 to 8 miles (approx. 8 to 13 km) from each other.
The low power transceiver from the cell phone transmits the voice and data to
the nearest cell site. During movement, the cell phone will "handoff" the
information to other cell site. Mobile phone operators use many technologies to
maintain the smooth stream of digitized data from the cell phone to the cell
site and vice versa.
The wireless telephone technologies are grouped under heads known as
generations, starting from zero generation or 0G. The current generation going
on is 4G; however, there are old cell phones (telefone celular) that still
operate on 1G, 2G, and 3G technologies. The wireless telephone technologies used
in each generation are as given below:
0G: PTT, MTS, IMTS, AMTS, OLT, MTD, Autotel/PALM, ARP 1G: NMT, AMPS/TACS/ETACS,
Hicap, CDPD, Mobitex, DataTac 2G: GSM, iDEN, D-AMPS, IS-95/cdmaOne, PDC, CSD,
PHS, GPRS, HSCSD, WiDEN, CDMA2000 1xRTT/IS-2000, EDGE (EGPRS) 3G: W-CDMA, UMTS
(3GSM), FOMA, TD-CDMA/UMTS-TDD, 1xEV-DO/IS-856, TD-SCDMA, GAN (UMA), HSPA, HSDPA,
HSUPA, HSPA+, HSOPA 4G : UMB, UMTS Revision 8 (LTE), WiMAX Frequency bands: SMR,
The impact of cell phone (telefone celular) usage on human health has been of
considerable worldwide concern. Research studies in Copenhagen, from the Danish
Institute of Cancer Epidemiology, the National Cancer Institute, and the
Institute of Cancer Research, do not establish any link between cancer and cell
phone usage. However, an intergovernmental agency IARC (International Agency for
Research on Cancer) forming part of the World Health Organization of the United
Nations, undertook a study of 4,500 users and found a statistically significant
link between cell phone usage and tumor frequency. Further research is going on.
Cell phone (telefone celular) usage and driving is a common worldwide
phenomenon. Some jurisdictions have banned usage of hand-held phones during
driving, but allowed the hands-free fashion of cell phone usage while driving.
However, studies have found out that the distraction is caused by the
conversation itself; hence, both hand-held and hands-free cell phones contribute
towards road traffic accidents. Further studies on cell phone usage and driving
are going on.
Nokia Corporation is currently the world`s largest manufacturer of cell phones
(telefone celular). Other notable cell phone manufacturers, in alphabetical
order, are 3G, Audiovox (now UT Starcom), Benefon, BenQ-Siemens, Fujitsu, High
Tech Computer Corporation (HTC), Kyocera, LG Mobile, Motorola, NEC, Panasonic
(Matsushita Electric), Pantech Curitel, Philips, Research In Motion, Sagem,
Samsung, Sanyo, Sharp, Siemens, Sierra Wireless, SK Teletech, Sony Ericsson, T&A
Alcatel, Toshiba, and Verizon.
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