Besides the traditional voice function of a telephone, brand new cell phones (telefone celular) have points together with SMS for text messages, MMS for multimedia messages, radio, games, cyber web 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, name registers, streaming video, downloading video, video name, and also serve as wireless modems for PCs that can be connected to the Internet.
The power in a mobile phone (telefone celular) is got from rechargeable batteries, which may be recharged from the mains, a USB port or a cigarette lighter port in an automobile. Nickel Metal Hydride were the commonest styles of batteries, which due to the "memory outcomes" (the user can recharge basically when the whole battery is drained off) were replaced by Lithium-Ion batteries, which did no longer suffer from any memory outcomes.
Cell phones (telefone celular) came into existence as a result of the invention of hexagonal cells in 1947, for the base stations by Bell Labs engineers at AT&T. This was additional developed all through the nineteen sixties by Bell Labs. During a name, the channel frequency couldn't be changed automatically from one cell (base station insurance plan area) to yet another cell (base station insurance plan area) as the person traveled from the area of one cell to the area of yet another cell. Amos Joel of Bell Labs invented a breakthrough invention and known as it as the `name handoff` by which the channel frequency would maybe be changed automatically from one cell to yet another cell, all through the identical name, as the mobile user traveled from one cell to yet another cell. Due to their heavy construction, those phones were used primarily in cars.
The first practical mobile phone in a non-vehicle setting, and which would maybe be handheld, was invented by Martin Cooper, the General Manager (Communications Division) of Motorola, who made the world`s first handheld mobile phone (telefone celular) name on April 3, 1973.
The technology by which the mobile phone (telefone celular) works relies upon on the mobile phone operator; nevertheless, all of them use electromagnetic radio waves, which are in touch with a cell site (base station). The base station is composed of a couple of antennas which are fastened 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 and each and every other. The low power transceiver from the mobile phone transmits the voice and info to the nearest cell site. During movement, the mobile phone will "handoff" the counsel to other cell site. Mobile phone operators use many applied sciences to sustain the clean stream of digitized info from the mobile phone to the cell site and vice versa.
The wireless telephone applied sciences are grouped under heads known as generations, starting from zero generation or 0G. The brand new generation going on is 4G; nevertheless, there are old cell phones (telefone celular) that also operate on 1G, 2G, and 3G applied sciences. The wireless telephone applied sciences used in each and each and every 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, Cellular, PCS
The impact of mobile 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 no longer establish any link between cancer and mobile 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 learned a statistically significant link between mobile phone usage and tumor frequency. Further research is happening.
Cell phone (telefone celular) usage and driving is a common worldwide phenomenon. Some jurisdictions have banned usage of hand-held phones all through driving, but allowed the hands-free fashion of mobile phone usage while driving. However, studies have learned out that the distraction is brought on by the conversation itself; hence, both hand-held and hands-free cell phones contribute towards road visitors accidents. Further studies on mobile phone usage and driving are going on.
Nokia Corporation is currently the world`s largest manufacturer of cell phones (telefone celular). Other distinct mobile 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.
This article is under GNU FDL license and can be distributed with out any previous authorization from the author. However the author's name and all the URLs (links) mentioned in the article and biography must be saved.
This article may also be accessed in portuguese language from the News Article section of page www.polomercantil.com.br/celular.php
Roberto Sedycias works as IT consultant for www.PoloMercantil.com.br