Terminology

Most current mobile phones connect to a cellular network of base stations (cell sites), which is in turn interconnected to the public switched telephone network (PSTN). Fully automatic cellular networks were first introduced in the early to mid 1980s (the 1G generation). The first fully automatic mobile phone system was the Nordic Mobile Telephone (NMT) system, introduced in 1981.

Prior mobile telephones (the so-called 0G generation), such as Mobile Telephone Service, date back to 1945. These were not categorized as mobile phones, since they did not support handover, i.e. automatic change of channel frequency in the middle of a call, when the user moved from one cell (base station coverage area) to another.

Until the late 1980s, most mobile phones were sufficiently large that they were permanently installed in vehicles as car phones. With the advance of miniaturization, currently the vast majority of mobile phones are handheld. In addition to the standard voice function of a telephone, a mobile phone can support many additional services such as SMS for text messaging, email, packet switching for access to the Internet, and MMS for sending and receiving photos and video.

Mobile phone manufacturers include Apple Inc., Sony Ericsson, T&A Alcatel, and Toshiba. Nokia Corporation is currently the world’s largest manufacturer of mobile telephones, with a global market share of approximately 36% in Q4 of 2006.

Mobile phones are also distinct from cordless telephones, which generally operate only within a limited range of a specific base station. Technically, the term mobile phone includes such devices as satellite phones and pre-cellular mobile phones such as those operating via MTS which do not have a cellular network, whereas the related term cell phone doesn't. In practice, the two terms are used nearly interchangeably, with the preferred term varying by location.

There are many different networks on mobile phones. Some are pay as you go, where top-ups can be purchased and added to a phone unit, so there is no monthly bill. Many are “pay monthly”, where a bill is issued every month for the amount of calls and text messages made.

At present, Africa has the largest growth rate of cellular subscribers in the world. African markets are expanding nearly twice as fast as Asian markets. The availability of Prepaid or pay as you go services, where the subscriber does not have to commit to a long term contract, has helped fuel this growth on a monumental scale, not only in Africa but on other continents as well.

In fewer than twenty years, mobile phones have gone from being rare and expensive pieces of equipment used primarily by the business elite, to a pervasive low-cost personal item. In many countries, mobile phones now outnumber land-line telephones.. In the United States, 50% of children own mobile phones. It is not uncommon for young adults to simply own a mobile phone instead of a land-line for their residence. In some developing countries, where there is little existing fixed-line infrastructure, the mobile phone has become widespread.

With high levels of mobile telephone penetration, a mobile culture has evolved, where the phone becomes a key social tool, and people rely on their mobile phone address book to keep in touch with their friends. Many people keep in touch using SMS, and a whole culture of “texting” has developed from this. The commercial market in SMS’s is growing. Many phones even offer Instant Messenger services to increase the simplicity and ease of texting on phones.

The mobile phone itself has also become a fashion object, with users decorating, customizing, and accessorizing their mobile phones to reflect their personality. The sale of commercial ringtones exceeded $2.5 billion in 2004.

The use of a mobile phone is prohibited in some railroad company carriages

Mobile phone etiquette has become an important issue with mobiles ringing at funerals, weddings, cinemas, and plays.Users often speak at increased volume which has led to places like book shops, libraries, movie theatres, doctors’ offices, and houses of worship posting signs prohibiting the use of mobile phones, and in some places installing signal-jamming equipment to prevent usage. Some new buildings such as auditoriums have installed wire mesh in the walls which prevents any signal getting through, but does not contravene the jamming laws.

Transportation providers, particularly those involving long-distance services, often offer a “quiet car” where phone use is prohibited, much like the designated non-smoking cars in the past. Mobile phone use on aircraft is also prohibited, because of concerns of possible interference with aircraft radio communications, although the airline Emirates have announced plans to allow limited mobile phone usage on some flights. Most schools in the United States have prohibited mobile phones in the classroom due to the high amount of class disruptions that result from their use, and due to the possibility of photographing someone without consent.

In Japan, mobile phone companies provide immediate notification of earthquakes and other natural disasters to their customers free of charge. In the event of an emergency, disaster response crews can locate trapped or injured people using the signals from their mobile phones; an interactive menu accessible through the phone’s Internet browser notifies the company if the user is safe or in distress.

Mobile phone features

Invented in 1997, the camera phone is now 85% of the market. In a recent Weekend America interview on public radio, Philippe Kahn, the inventor of the camera phone, discusses its social impact and how it connects people around the world [2]. Mobile phones also often have features beyond sending text messages and making voice calls—including Internet browsing, music (MP3) playback, memo recording, personal organizers, e-mail, built-in cameras and camcorders, ringtones, games, radio, Push-to-Talk (PTT), infrared and Bluetooth connectivity, call registers, ability to watch streaming video or download video for later viewing, video call and serve as a wireless modem for a PC.

Mobile phone forensics and evidence

The UK appears to be leading the world when in comes to mobile telephone forensics and evidence. Law enforcement globally, though, relies heavily upon mobile telephone evidence. The concerns over terrorism and terrorist use of technology promoted an enquiry by the UK House of Commons Home Affairs Select Committee into the use of evidence from mobile telephone devices, prompting leading mobile telephone forensic specialists to identify forensic techniques available in this area.

Mobile phones and the network they operate under vary significantly from provider to provider, and nation to nation. However, all of them communicate through electromagnetic microwaves with a cell site base station, the antennas of which are usually mounted on a tower, pole, or building.

The phones have a low-power transceiver that transmits voice and data to the nearest cell sites, usually 5 to 8 miles (approximately 8 to 13 kilometres) away. When the mobile phone or data device is turned on, it registers with the mobile telephone exchange, or switch, with its unique identifiers, and will then be alerted by the mobile switch when there is an incoming telephone call. The handset constantly listens for the strongest signal being received from the surrounding base stations. As the user moves around the network, the mobile device will “handoff” to various cell sites during calls, or while waiting (idle) between calls it will reselect cell sites.

Cell sites have relatively low-power (often only one or two watts) radio transmitters which broadcast their presence and relay communications between the mobile handsets and the switch. The switch in turn connects the call to another subscriber of the same wireless service provider or to the public telephone network, which includes the networks of other wireless carriers. Many of these sites are camouflaged to blend with existing environments, particularly in high-scenery areas.

The dialogue between the handset and the cell site is a stream of digital data that includes digitized audio (except for the first generation analog networks). The technology that achieves this depends on the system which the mobile phone operator has adopted. Some technologies include AMPS for analog, and D-AMPS, CDMA2000, GSM, GPRS, EV-DO, and UMTS for digital communications. Each network operator has a unique radio frequency band.

We are not the authors of this information, we thought it would be useful knowledge. This information can be found at:

http://en.wikipedia.org/wiki/Mobile_phone