Mobile Phone

Mobile phones generally obtain power from batteries which can be recharged from mains power, a USB port or a cigarette lighter socket in a car. Formerly, the most common form of mobile phone batteries were nickel metal-hydride, as they have a low size and weight. Lithium-Ion batteries are sometimes used, as they are lighter and do not have the voltage depression that nickel metal-hydride batteries do. Many mobile phone manufacturers have now switched to using lithium-Polymer batteries as opposed to the older Lithium-Ion, the main advantages of this being even lower weight and the possibility to make the battery a shape other than strict cuboid. Mobile phone manufacturers have been experimenting with alternate power sources, including solar cells.

Mobile phone use can be an important matter of social discourtesy: phones ringing during funerals or weddings; in toilets, cinemas and theatres. Users often speak loudly, leading to book shops, libraries, bathrooms, cinemas, doctors’ offices and places of worship prohibiting their use and, in some places, the installation of signal-jamming equipment to prevent their use (though in many countries, including the U.S., such equipment is currently illegal). Some new buildings, such as auditoriums, have installed wire mesh in the walls (making it a Faraday cage) which prevents signal penetration without violating signal jamming laws.Trains, particularly those involving long-distance services, often offer a “quiet carriage” where phone use is prohibited, much like the designated non-smoking carriage of the past. However many users tend to ignore this as it is rarely enforced, especially if the other carriages are crowded and they have no choice but to go in the “quiet carriage”. In Japan, it is generally considered impolite to talk using a phone on any train — texting is generally the mode of mobile communication.Mobile phone use on aircraft is also prohibited and many airlines claim in their in-plane announcements that this prohibition is due to possible interference with aircraft radio communications. Shut-off mobile phones do not interfere with aircraft avionics; the concern is partially based on the crash of Crossair Flight 498.

In less than twenty years, the mobile phone has gone from being rare, expensive equipment of the business elite to a pervasive, low-cost personal item. In many countries, mobile phones outnumber land-line phones; in the U.S., 50 percent of children have mobile phones.In many young adults’ households it has supplanted the land-line phone. The mobile phone is banned in some countries, such as North Korea.Given the high levels of societal mobile phone service penetration, it is a key means for people to communicate with each other. The SMS feature spawned the “texting” sub-culture.[citation needed] In December 1993, the first person-to-person SMS text message was transmitted in Finland. Currently, texting is the most widely-used data service; 1.8 billion users generated $80 billion of revenue in 2006 (source ITU).Many phones offer Instant Messenger services for simple, easy texting. Mobile phones have Internet service (e.g. NTT DoCoMo’s i-mode), offering text messaging via e-mail in Japan, South Korea, China, and India. In Europe, 30–40 per cent of internet access is via mobile phone. Most mobile internet access is much different from computer access, featuring alerts, weather data, e-mail, search engines, instant messages, and game and music downloading; most mobile internet access is hurried and short.The mobile phone can be a fashion totem custom-decorated to reflect the owner’s personality.This aspect of the mobile telephony business is, in itself, an industry, e.g. ringtone sales amounted to $3.5 billion in 2005.

An increasing number of countries, particularly in Europe, now have more mobile phones than people. According to the figures from Eurostat, the European Union’s in-house statistical office, Luxembourg had the highest mobile phone penetration rate at 158 mobile subscriptions per 100 people (158%), closely followed by Lithuania and Italy. In Hong Kong the penetration rate reached 139.8% of the population in July 2007.The U.S. currently has the mobile phone penetration rate of 81%. There are over five hundred million active mobile phone accounts in China, as of 2007, but the total penetration rate there still stands below 50%.The total number of mobile phone subscribers in the world was estimated at 2.14 billion in 2005.The subscriber count reached 2.7 billion by end of 2006 according to Informa[citation needed], and 3.3 billion by November, 2007[10], thus reaching an equivalent of over half the planet’s population. Around 80% of the world’s population enjoys mobile phone coverage as of 2006. This figure is expected to increase to 90% by the year 2010.At present, Africa has the largest growth rate of cellular subscribers in the world,its markets expanding nearly twice as fast as Asian markets.The availability of prepaid or ‘pay-as-you-go’ services, where the subscriber is not committed to a long term contract, has helped fuel this growth in Africa as well as in other continents.On a numerical basis, India is the largest growth market, adding about 6 million mobile phones every month.With 256.55 million mobile phones, market penetration in the country is still low at 22.52%. India expects to reach 500 million subscribers by end of 2010.There are three major technical standards for the current generation of mobile phones and networks, and two major standards for the next generation 3G phones and networks. All European, African and many Asian countries have adopted a single system, GSM, which is the only technology available on all continents and in most countries and covers over 74% of all subscribers on mobile networks. In many countries, such as the United States, Australia, Brazil, Costa Rica, India, Japan, and South Korea GSM co-exists with other internationally adopted standards such as CDMA and TDMA, as well as national standards such as iDEN in the USA and PDC in Japan. Over the past five years several dozen mobile operators (carriers) have abandoned networks on TDMA and CDMA technologies, switching over to GSM.With third generation (3G) networks, which are also known as IMT-2000 networks, about three out of four networks are on the W-CDMA (also known as UMTS) standard, usually seen as the natural evolution path for GSM and TDMA networks. One in four 3G networks is on the CDMA2000 1x EV-DO technology. Some analysts count a previous stage in CDMA evolution, CDMA2000 1x RTT, as a 3G technology whereas most standardization experts count only CDMA2000 1x EV-DO as a true 3G technology. Because of this difference in interpreting what is 3G, there is a wide variety in subscriber counts. As of June 2007, on the narrow definition there are 200 million subscribers on 3G networks. By using the more broad definition, the total subscriber count of 3G phone users is 475 million.While some systems of payment are ‘pay-as-you-go’ where conversation time is purchased and added to a phone unit via an Internet account or in shops or ATMs, other systems are more traditional ones where bills are paid by regular intervals. Pay as you go (also known as “pre-pay”) accounts were invented simultaneously in Portugal and Italy and today form more than half of all mobile phone subscriptions. USA, Canada, Costa Rica, Japan and Finland are among the rare countries left where most phones are still contract-based.