Market

In Q3/2008, Nokia was the world's largest manufacturer of mobile phones, with a global device market share of 39.4%, followed by Samsung (17.3%), Sony Ericsson (8.6%), Motorola (8.5%) and LG Electronics (7.7%). These manufacturers accounted for over 80% of all mobile phones sold at that time.^[16]

Other manufacturers include Apple Inc., Audiovox (now UTStarcom), Benefon, BenQ-Siemens, CECT,High Tech Computer Corporation (HTC), Fujitsu, Kyocera, Mitsubishi Electric, NEC, Neonode,Panasonic, Palm, Matsushita, Pantech Wireless Inc., Philips, Qualcomm Inc., Research in Motion Ltd. (RIM), Sagem, Sanyo, Sharp, Siemens, Sendo, Sierra Wireless, SK Teletech, T&A Alcatel,Huawei, Trium and Toshiba.^{[citation needed]} There are also specialist communication systems related to (but distinct from) mobile phones.

Media

The mobile phone became a mass media channel in 1998 when the first ringtones were sold to mobile phones by Radiolinja in Finland. Soon other media content appeared such as news, videogames, jokes, horoscopes, TV content and advertising. In 2006 the total value of mobile phone paid media content exceeded internet paid media content and was worth 31 Billion dollars (source Informa 2007). The value of music on phones was worth 9.3 Billion dollars in 2007 and gaming was worth over 5 billion dollars in 2007.^[17]

The mobile phone is often called the Fourth Screen (if counting cinema, TV and PC screens as the first three) or Third Screen (counting only TV and PC screens).^{[weasel words]} It is also called the Seventh of the Mass Media (with Print, Recordings, Cinema, Radio, TV and Internet the first six). Most early content for mobile tended to be copies of legacy media, such as the banner advertisement or the TV news highlight video clip. Recently unique content for mobile has been emerging, from the ringing tones and ringback tones in music to "mobisodes," video content that has been produced exclusively for mobile phones.

The advent of media on the mobile phone has also produced the opportunity to identify and track Alpha Users or Hubs, the most influential members of any social community. AMF Ventures measured in 2007 the relative accuracy of three mass media, and found that audience measures on mobile were nine times more accurate than on the internet and 90 times more accurate than on TV.^{[original research?]}

Related systems

Car phone

A type of telephone permanently mounted in a vehicle, these often have more powerful transmitters, an external antenna and loudspeaker for handsfree use. They usually connect to the same networks as regular mobile phones.

Cordless telephone (portable phone)

Cordless phones are telephones which use one or more radio handsets in place of a wired handset. The handsets connect wirelessly to a base station, which in turn connects to a conventional land line for calling. Unlike mobile phones, cordless phones use private base stations (belonging to the land-line subscriber), and which are not shared.

Professional Mobile Radio

Advanced professional mobile radio systems can be very similar to mobile phone systems. Notably, the IDEN standard has been used as both a private trunked radio system as well as the technology for several large public providers. Similar attempts have even been made to use TETRA, the European digital PMR standard, to implement public mobile networks.

Radio phone

This is a term which covers radios which could connect into the telephone network. These phones may not be mobile; for example, they may require a mains power supply, they may require the assistance of a human operator to set up a PSTN phone call.

Satellite phone

This type of phone communicates directly with an artificial satellite, which in turn relays calls to a base station or another satellite phone. A single satellite can provide coverage to a much greater area than terrestrial base stations. Since satellite phones are costly, their use is typically limited to people in remote areas where no mobile phone coverage exists, such as mountain climbers, mariners in the open sea, and news reporters at disaster sites.

WiFi Phones

This type of phone delivers calls over wireless internet networks using VoIP as opposed to traditional CDMA and GSM networks. Several vendors have developed standalone WiFi phones. Additionally, some cellular mobile phones include the ability to place VoIP calls over cellular high speed data networks and/or wireless internet.^[18]

Other Uses

Mobile phones are used for a variety of reasons including keeping in touch with family members, conducting business, or used in the event of an emergency. Some individuals keep multiple cell phones in some cases for legitimate reasons such as having one phone for business and another for personal use, though a second cell phone may also be used to covertly conduct an affair or illicit business transaction.Child predators are able to take advantage of cell phones to secretly communicate with children without the knowledge of their parents or teachers, which has raised concerns^[19].

Organizations that aid victims of domestic violence offer a secret cell phone to potential victims. These devices are often old phones that are donated and refurbished to meet the victim's emergency needs. The victim can then have the phone handy when necessary and without the abuser knowing^[20].

A study by Motorola found that one in ten cell phone subscribers have a second phone that often is kept secret from other family members. These phones are used to engage in activities including extramarital affairs or clandestine business dealings^[21].

The advent of widespread text messaging has resulted in the cell phone novel; the first literary genre to emerge from the cellular age viatext messaging to a website that collects the novels as a whole.^[22] Paul Levinson, in Information on the Move (2004), says "...nowadays, a writer can write just about as easily, anywhere, as a reader can read" and they are "not only personal but portable".

Privacy

Cell phones have numerous privacy issues associated with them, and are regularly used by governments to perform surveillance.

Law enforcement and intelligence services in the U.K. and the United States possess technology to remotely activate the microphones in cell phones in order to listen to conversations that take place nearby the person who holds the phone.^[23][24]

Mobile phones are also commonly used to collect location data. The geographical location of a mobile phone can be determined easily (whether it is being used or not), using a technique known multilateration to calculate the differences in time for a signal to travel from the cell phone to each of several cell towers near the owner of the phone. ^[25][26]

Health risks

Main article: Mobile phone radiation and health

Because mobile phones emit electromagnetic radiation, concerns have been raised about cancer risks that may pose when used for long periods of time.^[27] This radiation is non-ionizing, but localized heating can occur.

The current consensus view of the scientific and medical communities is that health effects are very unlikely to be caused by cellular phones or their base stations.^[28][29][30]

Cellular phones became widely available only relatively recently, while tumors can take decades to develop. For this reason, some health authorities have urged that the precautionary principle be observed, recommending that use and proximity to the head be minimized, especially by children.^[31][32]

Restriction on usage

Driving

Main article: Mobile phones and driving safety

Mobile phone use while driving is common but controversial. Being distracted while operating a motor vehicle has been shown to increase the risk of accident. Because of this, many governments have made the use of a mobile phone while driving illegal. Israel, Japan, Portugal and Singapore ban both hand-held and hands-free use of a mobile phone whilst many other countries ban hand-held phone use only.

Schools

Some schools limit or restrict the use of mobile phones. Schools set restrictions on the use of mobile phones because of the use of cell phones for cheating on tests, harassing other people, causing threats to the schools security, and facilitating gossip and other social activity in school. Many mobile phones are banned in school locker room facilities and in public restrooms. New camera phones are required to have a shutter effect when a photo is taken.^{[citation needed]}