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