Name Of Each Part Of A Mobile Phone

1. As of 2015, there were 7.4 billion subscriptions worldwide, though the actual number of users is lower as many users own more than one mobile phone. Mobile phones use electromagnetic radiation in the microwave range (450–3800 MHz and 24–80 GHz in 5G mobile).
2. A cell-phone carrier typically gets 832 radio frequencies to use in a city. Each cell phone uses two frequencies per call - a duplex channel - so there are typically 395 voice channels per carrier.

1. Name Of Each Part Of A Mobile Phone Book
2. Name Of Each Part Of A Mobile Phone Book
3. Name Of Each Part Of A Mobile Phone System

The most commonly used data application on mobile phones is SMS text messaging. The first SMS text message was sent from a computer to a mobile phone in 1992 in the UK, while the first person-to-person SMS from phone to phone was sent in Finland in 1993. The first mobile news service, delivered via SMS, was launched in Finland in 2000.

The effect of mobile phone radiation on human health is a subject of interest and study worldwide, as a result of the enormous increase in mobile phone usage throughout the world. As of 2015, there were 7.4 billion subscriptions worldwide, though the actual number of users is lower as many users own more than one mobile phone.^[1] Mobile phones use electromagnetic radiation in the microwave range (450–3800 MHz and 24–80 GHz in 5G mobile). Other digital wireless systems, such as data communication networks, produce similar radiation.

The World Health Organization states that 'A large number of studies have been performed over the last two decades to assess whether mobile phones pose a potential health risk. To date, no adverse health effects have been established as being caused by mobile phone use.'^[2] In a 2018 statement, the FDA said that 'the current safety limits are set to include a 50-fold safety margin from observed effects of Radio-frequency energy exposure'.^[3]

• 2Effects studied
• 6Precautions

Exposure[edit]

A cell phone is a wireless portable telephone that connects to the telephone network by radio waves exchanged with a local antenna and automated transceiver called a cellular base station (cell site or cell tower). The service area served by each provider is divided into small geographical areas called cells, and all the cell phones in a cell communicate with that cell's antenna. Both the cell phone and the cell tower have radio transmitters which communicate with each other. Since in a cellular network the same radio channels are reused every few cells, cellular networks use low power transmitters to avoid radio waves from one cell spilling over and interfering with a nearby cell using the same frequencies.

Cell phones are limited to a equivalent isotropic radiated power (EIRP) radiated power output of 3 watts, and the network continuously adjusts the phone transmitter to the lowest power consistent with good signal quality, reducing it to as low as one milliwatt when near the cell tower. Cell phone tower channel transmitters usually have an EIRP power output of around 50 watts. Even when it is not being used, unless it is turned off, a cell phone periodically emits radio signals on its control channel, to keep contact with its cell tower and for functions like handing off the phone to another tower if the user crosses into another cell. When the user is making a call, the cell phone transmits a signal on a second channel which carries the user's voice. Existing 2G, 3G, and 4G networks use frequencies in the UHF or low microwave bands, 600 MHz to 3.5 GHz. Many household wireless devices such as Wifi networks, garage door openers, and baby monitors use other frequencies in this same frequency range.

Radio waves decrease rapidly in intensity by the inverse square of distance as they spread out from a transmitting antenna. So the cell phone transmitter, which is held close to the user's face when talking, is a much greater source of human exposure than the cell tower transmitter, which is typically at least hundreds of meters away from the public on a cell tower. A user can reduce their exposure by using a headset and keeping the cell phone itself further away from their body.

Next generation 5G cellular networks, which began deploying in 2019, use higher frequencies in or near the millimeter wave band, 24 to 52 GHz.^[4][5] Millimeter waves are absorbed by atmospheric gases so 5G networks will use smaller cells than previous cellular networks, about the size of a city block. Instead of a cell tower, each cell will use an array of multiple small antennas mounted on existing buildings and utility poles. In general, millimeter waves penetrate less deeply into biological tissue than microwaves, and are mainly absorbed within the first centimeter of the body surface.

Effects studied[edit]

Blood–brain barrier[edit]

A 2010 review stated that 'The balance of experimental evidence does not support an effect of 'non-thermal' radiofrequency fields' on the permeability of the blood-brain barrier, but noted that research on low frequency effects and effects in humans was sparse.^[6] A 2012 study of low-frequency radiation on humans found 'no evidence for acute effects of short-term mobile phone radiation on cerebral blood flow'.^[7][8]

Cancer[edit]

There is limited consistent evidence that mobile phone use increases the risk of getting brain cancer or other head tumors. The United States National Cancer Institute points out that 'Radiofrequency energy, unlike ionizing radiation, does not cause DNA damage that can lead to cancer. Its only consistently observed biological effect in humans is tissue heating. In animal studies, it has not been found to cause cancer or to enhance the cancer-causing effects of known chemical carcinogens.' The majority of human studies so far have not consistently shown a link between cell phone use and cancer. However, in 2011 a World Health Organization working group classified cell phone use as 'possibly carcinogenic to humans' (class B). The CDC states that there is limited scientific evidence to definitively answer whether cell phone use causes cancer.^[7][9][10]

In a 2018 statement, the FDA said that 'the current safety limits are set to include a 50-fold safety margin from observed effects of radiofrequency energy exposure'.^[3][11]

An analysis of an 'eagerly anticipated' study using rats and mice by the National Toxicology Program indicates that due to such issues as the inconsistent appearances of 'signals for harm' within and across species and the increased chances of false positives due to the multiplicity of tests, the positive results seen are more likely due to random chance. The full results of the study were released in February 2018.^[12]

Male fertility[edit]

A decline in male sperm quality has been observed over several decades.^[13][14][15] Studies on the impact of mobile radiation on male fertility are conflicting, and the effects of the radiofrequencyelectromagnetic radiation (RF-EMR) emitted by these devices on the reproductive systems are currently under active debate.^{[16][17][18][19]} A 2012 review concluded that 'together, the results of these studies have shown that RF-EMR decreases sperm count and motility and increases oxidative stress'.^[20][21] A 2017 study of 153 men that attended an academic fertility clinic in Boston, Massachusetts found that self-reported mobile phone use was not related to semen quality, and that carrying a mobile phone in the pants pocket was not related to semen quality.^[22]

Electromagnetic hypersensitivity[edit]

Some users of mobile phones and similar devices have reported feeling various non-specific symptoms during and after use. Studies have failed to link any of these symptoms to electromagnetic exposure. In addition, EHS is not a recognised medical diagnosis.^[23]

Name Of Each Part Of A Mobile Phone Book

Glucose metabolism[edit]

According to the National Cancer Institute, two small studies exploring whether and how cell phone radiation affects brain glucose metabolism showed inconsistent results.^[7]

Base stations[edit]

Experts consulted by France considered it was mandatory that the main antenna axis should not to be directly in front of a living place at a distance shorter than 100 metres.^[24] This recommendation was modified in 2003^[25] to say that antennas located within a 100-metre radius of primary schools or childcare facilities should be better integrated into the cityscape and was not included in a 2005 expert report.^[26] The Agence française de sécurité sanitaire environnementale (fr) as of 2009, says that there is no demonstrated short-term effect of electromagnetic fields on health, but that there are open questions for long-term effects, and that it is easy to reduce exposure via technological improvements.^[27]

Safety standards and licensing[edit]

To protect the population living around base stations and users of mobile handsets, governments and regulatory bodies adopt safety standards, which translate to limits on exposure levels below a certain value. There are many proposed national and international standards, but that of the International Commission on Non-Ionizing Radiation Protection (ICNIRP) is the most respected one, and has been adopted so far by more than 80 countries. For radio stations, ICNIRP proposes two safety levels: one for occupational exposure, another one for the general population. Currently there are efforts underway to harmonise the different standards in existence.^[28]

Radio base licensing procedures have been established in the majority of urban spaces regulated either at municipal/county, provincial/state or national level. Mobile telephone service providers are, in many regions, required to obtain construction licenses, provide certification of antenna emission levels and assure compliance to ICNIRP standards and/or to other environmental legislation.

Many governmental bodies also require that competing telecommunication companies try to achieve sharing of towers so as to decrease environmental and cosmetic impact. This issue is an influential factor of rejection of installation of new antennas and towers in communities.

The safety standards in the US are set by the Federal Communications Commission (FCC). The FCC has based its standards primarily on those standards established by the National Council on Radiation Protection and Measurements (NCRP) a Congressionally chartered scientific organization located in the WDC area and the Institute of Electrical and Electronics Engineers (IEEE), specifically Subcommittee 4 of the 'International Committee on Electromagnetic Safety'.

Switzerland has set safety limits lower than the ICNIRP limits for certain 'sensitive areas' (classrooms, for example).^[29]

Lawsuits[edit]

In the US, personal injurylawsuits have been filed by individuals against cellphone manufacturers (including Motorola,^[30]NEC, Siemens, and Nokia) on the basis of allegations of causation of brain cancer and death. In US federal courts, expert testimony relating to science must be first evaluated by a judge, in a Daubert hearing, to be relevant and valid before it is admissible as evidence. In a 2002 case against Motorola, the plaintiffs alleged that the use of wireless handheld telephones could cause brain cancer and that the use of Motorola phones caused one plaintiff's cancer. The judge ruled that no sufficiently reliable and relevant scientific evidence in support of either general or specific causation was proffered by the plaintiffs, accepted a motion to exclude the testimony of the plaintiffs' experts, and denied a motion to exclude the testimony of the defendants' experts.^[31]

Two separate cases in Italy, in 2009^[32][33] and 2017,^[34][35] resulted in pensions being awarded to plaintiffs who had claimed their benignbrain tumors were the result of prolonged mobile phone use in professional tasks, for 5–6 hours a day, which they ruled different from non-professional use.

Precautions[edit]

Precautionary principle[edit]

In 2000, the World Health Organization (WHO) recommended that the precautionary principle could be voluntarily adopted in this case.^[36] It follows the recommendations of the European Community for environmental risks.

According to the WHO, the 'precautionary principle' is 'a risk management policy applied in circumstances with a high degree of scientific uncertainty, reflecting the need to take action for a potentially serious risk without awaiting the results of scientific research.' Other less stringent recommended approaches are prudent avoidance principle and as low as reasonably practicable. Although all of these are problematic in application, due to the widespread use and economic importance of wireless telecommunication systems in modern civilization, there is an increased popularity of such measures in the general public, though also evidence that such approaches may increase concern.^[37] They involve recommendations such as the minimization of cellphone usage, the limitation of use by at-risk population (e.g., children), the adoption of cellphones and microcells with as low as reasonably practicable levels of radiation, the wider use of hands-free and earphone technologies such as Bluetooth headsets, the adoption of maximal standards of exposure, RF field intensity and distance of base stations antennas from human habitations, and so forth.^{[citation needed]} Overall, public information remains a challenge as various health consequences are evoked in the literature and by the media, putting populations under chronic exposure to potentially worrying information.^[38]

Precautionary measures and health advisories[edit]

In May 2011, the World Health Organization's International Agency for Research on Cancer announced it was classifying electromagnetic fields from mobile phones and other sources as 'possibly carcinogenic to humans' and advised the public to adopt safety measures to reduce exposure, like use of hands-free devices or texting.^[39]

Some national radiation advisory authorities, including those of Austria,^[40] France,^[41]Germany,^[42] and Sweden,^[43] have recommended measures to minimize exposure to their citizens. Examples of the recommendations are:

• Use hands-free to decrease the radiation to the head.
• Keep the mobile phone away from the body.
• Do not use telephone in a car without an external antenna.

The use of 'hands-free' was not recommended by the British Consumers' Association in a statement in November 2000, as they believed that exposure was increased.^[44] However, measurements for the (then) UK Department of Trade and Industry^[45] and others for the French Agence française de sécurité sanitaire environnementale [fr]^[46] showed substantial reductions. In 2005, Professor Lawrie Challis and others said clipping a ferrite bead onto hands-free kits stops the radio waves travelling up the wire and into the head.^[47]

Several nations have advised moderate use of mobile phones for children.^[48] A journal by Gandhi et al. in 2006 states that children receive higher levels of Specific Absorption Rate (SAR). When 5- and 10-year olds are compared to adults, they receive about 153% higher SAR levels. Also, with the permittivity of the brain decreasing as one gets older and the higher relative volume of the exposed growing brain in children, radiation penetrates far beyond the mid-brain.^[49]

Bogus products[edit]

Products have been advertised that claim to shield people from EM radiation from cell phones; in the US the Federal Trade Commission published a warning that 'Scam artists follow the headlines to promote products that play off the news – and prey on concerned people.'^[50]

According to the FTC, 'there is no scientific proof that so-called shields significantly reduce exposure from electromagnetic emissions. Products that block only the earpiece – or another small portion of the phone – are totally ineffective because the entire phone emits electromagnetic waves.' Such shields 'may interfere with the phone's signal, cause it to draw even more power to communicate with the base station, and possibly emit more radiation.'^[50] The FTC has enforced false advertising claims against companies that sell such products.^[51]

See also[edit]

References[edit]

1. ^'Ericsson Mobility Report November 2015'(PDF).
2. ^'Electromagnetic fields and public health: mobile phones'. WHO. 8 October 2014. Retrieved 19 January 2018.
3. ^ ^abGrady, Denise (2 February 2018). 'Cancer Risk From Cellphone Radiation Is Small, Studies Show'. The New York Times. Retrieved 9 February 2018.
4. ^Nordrum, Amy; Clark, Kristen (27 January 2017). 'Everything you need to know about 5G'. IEEE Spectrum magazine. Institute of Electrical and Electronic Engineers. Retrieved 23 January 2019.
5. ^Hoffman, Chris (7 January 2019). 'What is 5G, and how fast will it be?'. How-To Geek website. How-To Geek LLC. Retrieved 23 January 2019.
6. ^Stam R (2010). 'Electromagnetic fields and the blood-brain barrier'. Brain Research Reviews (Review). 65 (1): 80–97. doi:10.1016/j.brainresrev.2010.06.001. PMID20550949.
7. ^ ^abcWhat has research shown about the possible cancer-causing effects of radiofrequency energy?, United States National Cancer Institute
8. ^Kwon MS, Vorobyev V, Kännälä S, et al. (2012). 'No effects of short-term GSM mobile phone radiation on cerebral blood flow measured using positron emission tomography'. Bioelectromagnetics. 33 (3): 247–56. doi:10.1002/bem.20702. PMID21932437.
9. ^Repacholi MH, Lerchl A, Röösli M, Sienkiewicz Z, Auvinen A, Breckenkamp J, d'Inzeo G, Elliott P, Frei P, Heinrich S, Lagroye I, Lahkola A, McCormick DL, Thomas S, Vecchia P (2012). 'Systematic review of wireless phone use and brain cancer and other head tumors'. Bioelectromagnetics (Systematic review). 33 (3): 187–206. doi:10.1002/bem.20716. PMID22021071.
10. ^'Electromagnetic fields and public health: mobile phones'. World Health Organization. October 2014. Retrieved 12 January 2017.
11. ^'Press Announcements - Statement from Jeffrey Shuren, M.D., J.D., director of the FDA's Center for Devices and Radiological Health on the recent National Toxicology Program draft report on radiofrequency energy exposure'. www.fda.gov. Retrieved 9 February 2018.
12. ^Labos, Christopher; Foster, Kenneth (2018). 'Cell Phone Radiation and Cancer: New NTP Results Inconsistent; Random Chance Likely at Play'. Skeptical Inquirer. 42 (4): 12–14.
13. ^McKie, Robin (29 July 2017). 'The infertility crisis is beyond doubt. Now scientists must find the cause'. The Guardian – via www.theguardian.com.
14. ^CNN, Susan Scutti. 'Sperm counts of Western men plummeting, analysis finds'. CNN.
15. ^Sengupta Pallav, Dutta Sulagna, Krajewska-Kulak Elzbieta (2016). 'The Disappearing Sperms: Analysis of Reports Published Between 1980 and 2015'. American Journal of Men's Health. 11 (4): 1279–1304. doi:10.1177/1557988316643383. PMC5675356. PMID27099345.CS1 maint: Multiple names: authors list (link)
16. ^Behari, Jitendra; Kumar, Sanjay; Kesari, Kavindra Kumar (1 October 2010). 'Mobile phone usage and male infertility in Wistar rats'. Indian Journal of Experimental Biology. 48 (10).
17. ^De Iuliis Geoffry N (2009). 'Mobile Phone Radiation Induces Reactive Oxygen Species Production and DNA Damage in Human Spermatozoa In Vitro'. PLoS ONE. 4 (7): e6446. Bibcode:2009PLoSO..4.6446D. doi:10.1371/journal.pone.0006446. PMC2714176. PMID19649291.
18. ^Kesari, Kavindra; Hamada, Alaa; Singh, Aspinder; Agarwal, Ashok (1 August 2011). 'Cell phones and male infertility: a review of recent innovations in technology and consequences'. International Braz J Urol. 37 (4): 432–454. doi:10.1590/S1677-55382011000400002.
19. ^Aitken, R. J.; Iuliis, G. N. De; King, B. V.; Nixon, B.; Houston, B. J. (1 December 2016). 'The effects of radiofrequency electromagnetic radiation on sperm function'. Reproduction. 152 (6): R263–R276. doi:10.1530/REP-16-0126. PMID27601711 – via rep.bioscientifica.com.
20. ^La Vignera S., Condorelli R. A., Vicari E., D'Agata R., Calogero A. E. (2012). 'Effects of the Exposure to Mobile Phones on Male Reproduction: A Review of the Literature'. Journal of Andrology. 33 (3): 350–356. doi:10.2164/jandrol.111.014373. PMID21799142.CS1 maint: Multiple names: authors list (link)
21. ^du Plessis, Stefan S.; Ong, Chloe; Virk, Gurpriya; Agarwal, Ashok (1 April 2014). 'Effect of Oxidative Stress on Male Reproduction'. The World Journal of Men's Health. 32 (1): 1–17. doi:10.5534/wjmh.2014.32.1.1. PMC4026229. PMID24872947.
22. ^Lewis Ryan C., Mínguez-Alarcón Lidia, Meeker John D., Williams Paige L., Mezei Gabor, Ford Jennifer B., Hauser Russ (2017). 'Self-reported mobile phone use and semen parameters among men from a fertility clinic'. Reproductive Toxicology. 67: 42–47. doi:10.1016/j.reprotox.2016.11.008. PMC5303122. PMID27838386.CS1 maint: Multiple names: authors list (link)
23. ^Röösli, Martin (June 2008). 'Radiofrequency electromagnetic field exposure and non-specific symptoms of ill health: A systematic review'. Environmental Research. 107 (2): 277–287. Bibcode:2008ER..107.277R. doi:10.1016/j.envres.2008.02.003. PMID18359015.
24. ^http://www.afsset.fr/index.php?pageid=712&parentid=424 page 37
25. ^Téléphonie mobile et santé, Rapport à l'Agence Française de Sécurité Sanitaire Environnementale, 21 March 2003 at http://www.afsset.fr/index.php?pageid=712&parentid=424
26. ^Téléphonie mobile et santé, Rapport du groupe d’experts, l'Agence Française de Sécurité Sanitaire Environnementale, April 2005 at http://www.afsset.fr/index.php?pageid=712&parentid=424
27. ^'Radiofréquences : actualisation de l'expertise (2009)', l'Agence Française de Sécurité Sanitaire Environnementale, April 2005 at http://www.afsset.fr/index.php?pageid=712&parentid=424
28. ^'International Commission for Non-Ionizing Radiation Protection home page'. Retrieved 7 January 2008.
29. ^'Anforderungen nach NISV: Mobilfunkanlagen' [Specifications of the Regulation on Non-Ionizing Radiation: Mobile Telephone Installations] (in German). Bundesamt für Umwelt [Swiss Federal Environment Ministry]. 13 March 2009. Retrieved 20 January 2010.
30. ^'Wright v. Motorola, Inc. et al., No95-L-04929'.
31. ^Christopher Newman, et al. v Motorola, Inc., et al. (United States District Court for the District of Maryland) ('Because no sufficiently reliable and relevant scientific evidence in support of either general or specific causation has been proffered by the plaintiffs, as explained below, the defendants’ motion will be granted and the plaintiffs’ motion will be denied.'). Text
32. ^'Tumore e telefonini, il testo della sentenza n.17438 della Cassazione' [Tumor and cell phones, the text of the judgment n.17438 of the Supreme Court]. www.leggioggi.it (in Italian). 19 October 2012. Retrieved 1 March 2017.
33. ^'Italy court ruling links mobile phone use to tumour'. Reuters. 19 October 2012. Retrieved 4 May 2017.
34. ^'Italian court rules mobile phone use caused brain tumour'. The Guardian. 21 April 2017. Retrieved 4 May 2017 – via Agence France-Presse.
35. ^'Cancer Linked to Cellphone Use, Italian Court Rules in Landmark Case'. Newsweek. 21 March 2017. Retrieved 7 May 2017.
36. ^'Electromagnetic Fields and Public Health: Cautionary Policies'. World Health Organization Backgrounder. World Health Organization. March 2000. Retrieved 1 February 2008.
37. ^Wiedemann; et al. (2006). 'The Impacts of Precautionary Measures and the Disclosure of Scientific Uncertainty on EMF Risk Perception and Trust'. Journal of Risk Research. 9 (4): 361–372. doi:10.1080/13669870600802111.
38. ^Poumadère M.; Perrin A. (2013). 'Risk Assessment of Radiofrequencies and Public Information'. Journal of Risk Analysis and Crisis Response. 3 (1): 3–12. doi:10.2991/jrarc.2013.3.1.1.
39. ^http://www.iarc.fr/en/media-centre/pr/2011/pdfs/pr208_E.pdf
40. ^'Information: Wie gefährlich sind Handystrahlen wirklich?' (in German). Marktgemeinde Pressbaum. Archived from the original on 2 October 2011. Retrieved 16 May 2015.
41. ^'Téléphones mobiles : santé et sécurité' (in French). Le ministère de la santé, de la jeunesse et des sports. 2 January 2008. Retrieved 19 January 2008. Lay article in ‹See Tfd›(in English) making comment at Gitlin, Jonathan M. (3 January 2008). 'France: Beware excessive cell phone use?: despite lack of data'. Ars Technica. Retrieved 19 January 2008.
42. ^'Precaution regarding electromagnetic fields'. Federal Office for Radiation Protection. 7 December 2007. Retrieved 19 January 2008.
43. ^'Exponering' (in Swedish). Swedish Radiation Protection Authority. February 2006. Retrieved 19 January 2008.
44. ^'UK consumer group: Hands-free phone kits boost radiation exposure'. cnn.com. Cable News Network. 2 November 2000. Archived from the original on 14 March 2006.
45. ^Manning, MI and Gabriel, CHB, SAR tests on mobile phones used with and without personal hands-free kits, SARtest Report 0083 for the DTI, July 2000 (PDF) at http://straff-x.com/SAR-Hands-Free-Kits-July-2000.pdf
46. ^Téléphonie mobile & santé, Report for l'Agence française de sécurité sanitaire environnementale (Afsse), June 2005 at http://www.afsse.fr/index.php?pageid=671&parentid=619#
47. ^'Bead 'slashes mobile radiation''. BBC News. 25 January 2005. Retrieved 17 March 2009.
48. ^For example, Finland 'Radiation and Nuclear Safety Authority: Children's mobile phone use should be limited'. Finnish Radiation and Nuclear Safety Authority (STUK). 7 January 2009. Archived from the original on 11 January 2010. Retrieved 20 January 2010. and France 'Téléphone mobile, DAS et santé' [Mobile telephones, SAR and health] (PDF). Votre enfant et le téléphone mobile [Your child and mobile telephony]. Association Française des Opérateurs Mobiles (AFOM)[French Mobile Phone Operators' Association] et l’Union Nationale des Associations Familiales (UNAF) [National Federation of Family Associations]. 31 January 2007. Retrieved 20 January 2010.
49. ^Gandhi, Om P.; Morgan, L. Lloyd; de Salles, Alvaro Augusto; Han, Yueh-Ying; Herberman, Ronald B.; Davis, Devra Lee (14 October 2011). 'Exposure Limits: The underestimation of absorbed cell phone radiation, especially in children'. Electromagnetic Biology and Medicine. 31 (1): 34–51. doi:10.3109/15368378.2011.622827. ISSN1536-8378. PMID21999884.
50. ^ ^ab'Cell Phone Radiation Scams'. Federal Trade Commission. September 2011.
51. ^Fair, Lesley (1 March 2008). 'Federal Trade Commission Advertising Enforcement'(PDF). Federal Trade Commission. pp. 18–19.

External links[edit]

• Summary and full text of 'Possible effects of Electromagnetic Fields (EMF) on Human Health', the 2007 scientific assessment of the European Commission's SCENIHR (Scientific Committee on Emerging and Newly Identified Health Risks).

The features of mobile phones are the set of capabilities, services and applications that they offer to their users. Mobile phones are often referred to as feature phones, and offer basic telephony.^{[clarification needed]} Handsets with more advanced computing ability through the use of native code try to differentiate their own products by implementing additional functions to make them more attractive to consumers. This has led to great innovation in mobile phone development over the past 20 years.

The common components found on all phones are:

• A battery, providing the power source for the phone functions.
• An input mechanism to allow the user to interact with the phone. The most common input mechanism is a keypad, but touch screens are also found in smartphones.
• Basic mobile phone services to allow users to make calls and send text messages.
• All GSM phones use a SIM card to allow an account to be swapped among devices. Some CDMA devices also have a similar card called a R-UIM.
• Individual GSM, WCDMA, iDEN and some satellite phone devices are uniquely identified by an International Mobile Equipment Identity (IMEI) number.

All mobile phones are designed to work on cellular networks and contain a standard set of services that allow phones of different types and in different countries to communicate with each other. However, they can also support other features added by various manufacturers over the years:

• roaming which permits the same phone to be used in multiple countries, providing that the operators of both countries have a roaming agreement.
• send and receive data and faxes (if a computer is attached), access WAP services, and provide full Internet access using technologies such as GPRS.
• applications like a clock, alarm, calendar, contacts, and calculator and a few games.
• Sending and receiving pictures and videos (by without internet) through MMS, and for short distances with e.g. Bluetooth.
• In Multimedia phones Bluetooth is commonly but important Feature.
• GPS receivers integrated or connected (i.e. using Bluetooth) to cell phones, primarily to aid in dispatchingemergency responders and road tow truck services. This feature is generally referred to as E911.
• Push to talk, available on some mobile phones, is a feature that allows the user to be heard only while the talk button is held, similar to a walkie-talkie.

• 2Power supply
• 3SIM card
• 7Multi-mode and multi-band mobile phones

Software, applications and services[edit]

In early stages, every mobile phone company had its own user interface, which can be considered as 'closed' operating system, since there was a minimal configurability. A limited variety of basic applications (usually games, accessories like calculator or conversion tool and so on) was usually included with the phone and those were not available otherwise. Early mobile phones included basic web browser, for reading basic WAP pages. Handhelds (Personal digital assistants like Palm, running Palm OS) were more sophisticated and also included more advanced browser and a touch screen (for use with stylus), but these were not broadly used, comparing to standard phones. Other capabilities like Pulling and Pushing Emails or working with calendar were also made more accessible but it usually required physical (and not wireless) Syncing. BlackBerry 850, an email pager, released January 19, 1999, was the first device to integrate Email.

A major step towards a more 'open' mobile OS was the symbian S60 OS, that could be expanded by downloading software (written in C++, java or python), and its appearance was more configurable. In July 2008, Apple introduced its App store, which made downloading mobile applications more accessible. In October 2008, the HTC Dream was the first commercially released device to use the Linux-based Android OS, which was purchased and further developed by Google and the Open Handset Alliance to create an open competitor to other major smartphone platforms of the time (Mainly Symbian operating system, BlackBerry OS, and iOS)-The operating system offered a customizable graphical user interface and a notification system showing a list of recent messages pushed from apps.

The most commonly used data application on mobile phones is SMS text messaging. The first SMS text message was sent from a computer to a mobile phone in 1992 in the UK, while the first person-to-person SMS from phone to phone was sent in Finland in 1993.

The first mobile news service, delivered via SMS, was launched in Finland in 2000. Mobile news services are expanding with many organizations providing 'on-demand' news services by SMS. Some also provide 'instant' news pushed out by SMS.

Mobile payments were first trialled in Finland in 1998 when two Coca-Cola vending machines in Espoo were enabled to work with SMS payments. Eventually, the idea spread and in 1999 the Philippines launched the first commercial mobile payments systems, on the mobile operators Globe and Smart. Today, mobile payments ranging from mobile banking to mobile credit cards to mobile commerce are very widely used in Asia and Africa, and in selected European markets. Usually, the SMS services utilize short code.

Some network operators have utilized USSD for information, entertainment or finance services (e.g. M-Pesa).

Other non-SMS data services used on mobile phones include mobile music, downloadable logos and pictures, gaming, gambling, adult entertainment and advertising. The first downloadable mobile content was sold to a mobile phone in Finland in 1998, when Radiolinja (now Elisa) introduced the downloadable ringtone service. In 1999, Japanese mobile operator NTT DoCoMo introduced its mobile Internet service, i-Mode, which today is the world's largest mobile Internet service.

Even after the appearance of smartphones, network operators have continued to offer information services, although in some places, those services have become less common.

Power supply[edit]

Mobile phones generally obtain power from rechargeable batteries. There are a variety of ways used to charge cell phones, including USB, portable batteries, mains power (using an AC adapter), cigarette lighters (using an adapter), or a dynamo. In 2009, the first wireless charger was released for consumer use.^[2] Some manufacturers have been experimenting with alternative power sources, including solar cells.^[3]

Various initiatives, such as the EU Common External Power Supply have been announced to standardize the interface to the charger, and to promote energy efficiency of mains-operated chargers. A star rating system is promoted by some manufacturers, where the most efficient chargers consume less than 0.03 watts and obtain a five-star rating.

Get to know about the best and fastest phone chargers.

Battery[edit]

A popular early mobile phone battery was the nickel metal-hydride (NiMH) type, due to its relatively small size and low weight. Lithium ion batteries are also used, as they are lighter and do not have the voltage depression due to long-term over-charging that nickel metal-hydride batteries do. Many mobile phone manufacturers use lithium–polymer batteries as opposed to the older lithium-ion, the main advantages being even lower weight and the possibility to make the battery a shape other than strict cuboid.^[4]

SIM card[edit]

GSM mobile phones require a small microchip called a Subscriber Identity Module or SIM card, to function. The SIM card is approximately the size of a small postage stamp and is usually placed underneath the battery in the rear of the unit. The SIM securely stores the service-subscriber key (IMSI) used to identify a subscriber on mobile telephony devices (such as mobile phones and computers). The SIM card allows users to change phones by simply removing the SIM card from one mobile phone and inserting it into another mobile phone or broadband telephony device.

A SIM card contains its unique serial number, internationally unique number of the mobile user (IMSI), security authentication and ciphering information, temporary information related to the local network, a list of the services the user has access to and two passwords (PIN for usual use and PUK for unlocking).

SIM cards are available in three standard sizes. The first is the size of a credit card (85.60 mm × 53.98 mm x 0.76 mm, defined by ISO/IEC 7810 as ID-1). The newer, most popular miniature version has the same thickness but a length of 25 mm and a width of 15 mm (ISO/IEC 7810 ID-000), and has one of its corners truncated (chamfered) to prevent misinsertion. The newest incarnation known as the 3FF or micro-SIM has dimensions of 15 mm × 12 mm. Most cards of the two smaller sizes are supplied as a full-sized card with the smaller card held in place by a few plastic links; it can easily be broken off to be used in a device that uses the smaller SIM.

The first SIM card was made in 1991 by Munich smart card maker Giesecke & Devrient for the Finnish wireless network operator Radiolinja. Giesecke & Devrient sold the first 300 SIM cards to Elisa (ex. Radiolinja).

Those cell phones that do not use a SIM card have the data programmed into their memory. This data is accessed by using a special digit sequence to access the 'NAM' as in 'Name' or number programming menu. From there, information can be added, including a new number for the phone, new Service Provider numbers, new emergency numbers, new Authentication Key or A-Key code, and a Preferred Roaming List or PRL. Download lagu rohani julius sitanggang full hd. However, to prevent the phone being accidentally disabled or removed from the network, the Service Provider typically locks this data with a Master Subsidiary Lock (MSL). The MSL also locks the device to a particular carrier when it is sold as a loss leader.

The MSL applies only to the SIM, so once the contract has expired, the MSL still applies to the SIM. The phone, however, is also initially locked by the manufacturer into the Service Provider's MSL. This lock may be disabled so that the phone can use other Service Providers' SIM cards. Most phones purchased outside the U.S. are unlocked phones because there are numerous Service Providers that are close to one another or have overlapping coverage. The cost to unlock a phone varies but is usually very cheap and is sometimes provided by independent phone vendors.

A similar module called a Removable User Identity Module or RUIM card is present in some CDMA networks, notably in China and Indonesia.

Multi-card hybrid phones[edit]

A hybrid mobile phone can take more than one SIM card, even of different types. The SIM and RUIM cards can be mixed together, and some phones also support three or four SIMs.^[5][6]

From 2010 onwards they became popular in India and Indonesia and other emerging markets,^[7] attributed to the desire to obtain the lowest on-net calling rate. In Q3 2011, Nokia shipped 18 million of its low cost dual SIM phone range in an attempt to make up lost ground in the higher end smartphone market.^[8]

Display[edit]

Mobile phones have a display device, some of which are also touch screens. The screen size varies greatly by model and is usually specified either as width and height in pixels or the diagonal measured in inches.

Some mobiles have more than one display, for example the Kyocera Echo, an Androidsmartphone with a dual 3.5 inch screen. The screens can also be combined into a single 4.7 inch tablet style computer.^[9]

Central processing unit[edit]

Mobile phones have central processing units (CPUs), similar to those in computers, but optimised to operate in low power environments.

Mobile CPU performance depends not only on the clock rate (generally given in multiples of hertz)^[10] but also the memory hierarchy also greatly affects overall performance. Because of these problems, the performance of mobile phone CPUs is often more appropriately given by scores derived from various standardized tests to measure the real effective performance in commonly used applications.

Miscellaneous features[edit]

Other features that may be found on mobile phones include GPS navigation, music (MP3) and video (MP4) playback, RDS radio receiver, built-in projector, vibration and other 'silent' ring options, alarms, memo recording, personal digital assistant functions, ability to watch streaming video, video download, video calling, built-in cameras (1.0+ Mpx) and camcorders (video recording), with autofocus^[dubious] and flash, ringtones, games, PTT, memory card reader (SD), USB (2.0), dual line support, infrared, Bluetooth (2.0) and WiFi connectivity, NFC, instant messaging, Internet e-mail and browsing and serving as a wireless modem.

The first smartphone was the Nokia 9000 Communicator^[dubious] in 1996 which added PDA functionality to the basic mobile phone at the time. As miniaturization and increased processing power of microchips has enabled ever more features to be added to phones, the concept of the smartphone has evolved, and what was a high-end smartphone five years ago, is a standard phone today.

Several phone series have been introduced to address a given market segment, such as the RIM BlackBerry focusing on enterprise/corporate customer email needs; the SonyEricsson Walkman series of musicphones and Cybershot series of cameraphones; the Nokia Nseries of multimedia phones, the Palm Pre the HTC Dream and the Apple iPhone.

Nokia and the University of Cambridge demonstrated a bendable cell phone called the Morph.^[11] Some phones have an electromechanical transducer on the back which changes the electrical voice signal into mechanical vibrations. The vibrations flow through the cheek bones or forehead allowing the user to hear the conversation. This is useful in the noisy situations or if the user is hard of hearing.^[12]

As of 2018, there are smartphones that offer reverse wireless charging.^[13]

Multi-mode and multi-band mobile phones[edit]

Most mobile phone networks are digital and use the GSM, CDMA or iDEN standard which operate at various radio frequencies. These phones can only be used with a service plan from the same company. For example, a Verizon phone cannot be used with a T-Mobile service, and vica versa.

A multi-mode phone operates across different standards whereas a multi-band phone (also known more specifically as dual, tri or quad band) mobile phone is a phone which is designed to work on more than one radio frequency. Some multi-mode phones can operate on analog networks as well (for example, dual band, tri-mode: AMPS 800 / CDMA 800 / CDMA 1900).

For a GSM phone, dual-band usually means 850 / 1900 MHz in the United States and Canada, 900 / 1800 MHz in Europe and most other countries. Tri-band means 850 / 1800 / 1900 MHz or 900 / 1800 / 1900 MHz. Quad-band means 850 / 900 / 1800 / 1900 MHz, also called a world phone, since it can work on any GSM network.

Name Of Each Part Of A Mobile Phone Book

Multi-band phones have been valuable to enable roaming whereas multi-mode phones helped to introduce WCDMA features without customers having to give up the wide coverage of GSM. Almost every single true 3G phone sold is actually a WCDMA/GSM dual-mode mobile. This is also true of 2.75G phones such as those based on CDMA-2000 or EDGE.

Challenges in producing multi-mode phones[edit]

The special challenge involved in producing a multi-mode mobile is in finding ways to share the components between the different standards. Obviously, the phone keypad and display should be shared, otherwise it would be hard to treat as one phone. Beyond that, though, there are challenges at each level of integration. How difficult these challenges are depends on the differences between systems. When talking about IS-95/GSM multi-mode phones, for example, or AMPS/IS-95 phones, the base band processing is very different from system to system. This leads to real difficulties in component integration and so to larger phones.

An interesting special case of multi-mode phones is the WCDMA/GSM phone. The radio interfaces are very different from each other, but mobile to core network messaging has strong similarities, meaning that software sharing is quite easy. Probably more importantly, the WCDMA air interface has been designed with GSM compatibility in mind. It has a special mode of operation, known as punctured mode, in which, instead of transmitting continuously, the mobile is able to stop sending for a short period and try searching for GSM carriers in the area. This mode allows for safe inter-frequency handovers with channel measurements which can only be approximated using 'pilot signals' in other CDMA based systems.

A final interesting case is that of mobiles covering the DS-WCDMA and MC-CDMA3G variants of the CDMA-2000 protocol. Initially, the chip rate of these phones was incompatible. As part of the negotiations related to patents, it was agreed to use compatible chip rates. This should mean that, despite the fact that the air and system interfaces are quite different, even on a philosophical level, much of the hardware for each system inside a phone should be common with differences being mostly confined to software.

Data communications[edit]

Mobile phones are now heavily used for data communications. such as SMS messages, browsing mobile web sites, and even streaming audio and video files. The main limiting factors are the size of the screen, lack of a keyboard, processing power and connection speed. Most cellphones, which supports data communications, can be used as wireless modems (via cable or bluetooth), to connect computer to internet. Such access method is slow and expensive, but it can be available in very remote areas.

With newer smartphones, screen resolution and processing power has become bigger and better. Some new phone CPUs run at over 1 GHz. Many complex programs are now available for the various smartphones, such as Symbian and Windows Mobile.

Connection speed is based on network support. Originally data transfers over GSM networks were possible only over CSD (circuit switched data), it has bandwidth of 9600 bit/s and usually is billed by connection time (from network point of view, it does not differ much from voice call). Later, there were introduced improved version of CSD - HSCSD (high speed CSD), it could use multiple time slots for downlink, improving speed. Maximum speed for HSCSD is ~42 kbit/s, it also is billed by time. Later was introduced GPRS (general packet radio service), which operates on completely different principle. It also can use multiple time slots for transfer, but it does not tie up radio resources, when not transferring data (as opposed to CSD and like). GPRS usually is prioritized under voice and CSD, so latencies are large and variable. Later, GPRS was upgraded to EDGE, which differs mainly by radio modulation, squeezing more data capacity in same radio bandwidth. GPRS and EDGE usually are billed by data traffic volume. Some phones also feature full Qwerty keyboards, such as the LG enV.

As of April 2006, several models, such as the Nokia 6680, support 3G communications. Such phones have access to the Web via a free download of the Opera web browser. Verizon Wireless models come with Internet Explorer pre-loaded onto the phone.

Vulnerability to viruses[edit]

As more complex features are added to phones, they become more vulnerable to viruses which exploit weaknesses in these features. Even text messages can be used in attacks by worms and viruses.^{[citation needed]} Advanced phones capable of e-mail can be susceptible to viruses that can multiply by sending messages through a phone's address book.^{[citation needed]} In some phone models, the USSD was exploited for inducing a factory reset,^[14] resulting in clearing the data and resetting the user settings.

A virus may allow unauthorized users to access a phone to find passwords or corporate data stored on the device. Moreover, they can be used to commandeer the phone to make calls or send messages at the owner's expense.^{[citation needed]}

Mobile phones used to have proprietary operating system unique only to the manufacturer which had the beneficial effect of making it harder to design a mass attack. However, the rise of software platforms and operating systems shared by many manufacturers such as Java, Microsoft operating systems, Linux, or Symbian OS, may increase the spread of viruses in the future.

Name Of Each Part Of A Mobile Phone System

Bluetooth is a feature now found in many higher-end phones, and the virus Caribe hijacked this function, making Bluetooth phones infect other Bluetooth phones running the Symbian OS. In early November 2004, several web sites began offering a specific piece of software promising ringtones and screensavers for certain phones. Those who downloaded the software found that it turned each icon on the phone's screen into a skull-and-crossbones and disabled their phones, so they could no longer send or receive text messages or access contact lists or calendars. The virus has since been dubbed 'Skulls' by security experts. The Commwarrior-A virus was identified in March 2005, and it attempts to replicate itself through MMS to others on the phone's contact list. Like Cabir, Commwarrior-A also tries to communicate via Bluetooth wireless connections with other devices, which can eventually lead to draining the battery. The virus requires user intervention for propagation however.

Bluetooth phones are also subject to bluejacking, which although not a virus, does allow for the transmission of unwanted messages from anonymous Bluetooth users.

Cameras[edit]

Most current phones also have a built-in digital camera (see camera phone), that can have resolutions as high as 48M pixels.^[15] This gives rise to some concern about privacy, in view of possible voyeurism, for example in swimming pools. South Korea has ordered manufacturers to ensure that all new handsets emit a beep whenever a picture is taken.

Sound recording and video recording is often also possible. Most people do not walk around with a video camera, but do carry a phone. The arrival of video camera phones is transforming the availability of video to consumers, and helps fuel citizen journalism.

See also[edit]

References[edit]

1. ^Sheen, James (22 October 2009). 'Meeting 30mW Standby in Mobile Phone Chargers'. Electronic Products. Retrieved 4 November 2009.
2. ^goingcellular.com — Powermat wireless charger now available
3. ^Charge Use Mini Solar Panel Android Phones.
4. ^'Cell Phone Battery Guide'. Retrieved 16 June 2010.
5. ^Example of a Triple SIM hybrid phone.
6. ^The Latest F160 Quad Sim Quad Standby TV Java Phone with Qwerty Keyboard Tri Sim Phones.
7. ^https://news.yahoo.com/s/nm/20110429/wr_nm/us_handsetsArchived May 8, 2011, at the Wayback Machine
8. ^'Nokia boosted by sales of cheap handsets'. October 20, 2011.
9. ^Kyocera Echo Phone Review PCWorld.
10. ^'CPU Frequency'. CPU World Glossary. CPU World. 25 March 2008. Retrieved 1 January 2010.
11. ^Reardon, Marguerite. 'Nokia demos bendable cell phone'. CNET News, February 25, 2008. Retrieved 20 July 2009.
12. ^Mito 228: Unique Handphone, Can Hear with the cheek, IeuMart.com
13. ^Huawei Takes a Jab at Apple – Says Its Mate 20 Pro Will Be Able to Charge iPhones Wirelessly
14. ^https://www.engadget.com/2012/09/25/dirty-ussd-code-samsung-hack-wipe/
15. ^https://m.gsmarena.com/oppo_reno_10x_zoom-9654.php