Mobile Technologies

In less than two decades, cellular phones have gone from being rare and expensive pieces of equipment used by businesses to necessities owned by both adults and children. In many countries, cellular phones now outnumber land-line telephones. Today they have evolved from merely a device for making calls. Phone features can now include Internet browsing, music (MP3) playback, personal organizers, e-mail, built-in cameras and camcorders, ringtones, games, radio, Push To Talk (PTT), infrared and bluetooth connectivity, call registers, and ability to watch streaming video or download video for later viewing. By 2008, the wireless market will reach $212 billion in the US alone. Some of the world's largest cellular phone manufacturers include Alcatel (France), Audiovox (US), LG (Korea), Motorola (US), Nokia (Finland), Panasonic (Japan), Sagem (France), Samsung (Korea), Siemens (Germany), Sony Ericsson (UK), and Toshiba (Japan). Mobile network carriers, such as Vodafone (UK), Telefonica (Spain), Orange (France), T-Mobile (Germany), China Mobile, and Cingular (US), are also major players with abilities to change the dynamics of this industry. Many other companies are eager to get a piece of the pie as well.

Throughout the evolution of cellular telecommunications, various incompatible standards for cellular, wireless, or mobile phones were developed. Attempts to achieve a world-wide mobile phone standard have been thwarted by competing technology companies and political interests. The European Union has passed legislation mandating the use of the GSM and its 3G successors as the single mobile phone system in their countries in order to maximize interoperability. In North America, there is a mix of incompatible digital networks run by competing operators using GSM, CDMA, or TDMA technology. The GSM service here operates mostly at 850 Mhz or 1900 Mhz, while 900 Mhz and 1800 Mhz are popular in other counties. The good news for world travelers is that most cellular phone manufacturers offer tri-band (900, 1800 and 1900 Mhz) and a growing number of quad-band (850, 900, 1800 and 1900 Mhz) phones that will work essentially in any network. In Japan, NTT DoCoMo led the move to next-generation mobile applications when its iMode network launched in February 1999.

Code Division Multiple Access

CDMA, developed by Qualcomm, is used in the US by both Sprint PCS and Verizon. Unlike competing systems, CDMA does not assign a specific frequency to each user. Instead, every channel uses the full available spectrum. In the purest technical sense, CDMA is more efficient than GSM. It works better inside buildings, thus often eliminating the need to mount an antenna on the outside. The CDMA technique is used as the principle of the Wideband-CDMA air interface, which is used in the global 3G standard UMTS and the Japanese 3G standard FOMA. Worldwide, there are approximately 300 million CDMA subscribers.

Global System for Mobile Communications

More than 1.6 billion people use GSM phones as of 2005, making GSM the dominant mobile phone system worldwide with about 70% of the world's market. While growing rapidly in the US, GSM service can be scarce outside of larger urban areas. The two major operators using GSM technologies are Cingular and T-Mobile. One of the key features of GSM is the Subscriber Identity Module (SIM), commonly known as a SIM card. The SIM is a detachable smartcard containing the user's subscription information and phonebook. This allows the user to retain his information after switching handsets. Alternatively, the user can also change operators while retaining the handset simply by changing the SIM. Some operators will block this by allowing the phone to use only a single SIM, or only a SIM issued by them. This practice is known as SIM locking. Roaming with GSM phones is a major advantage over the competing technology as roaming across CDMA networks from different operators can be difficult or impossible, if the operators lack a roaming agreement or work on different frequency bands.

Time Division Multiple Access

The first digital network widely used in the Americas, TDMA is the system which at one time was the core of major US wireless networks. Some industry analysts are forecasting that the increasing growth of GSM and CDMA in the Americas will eventually signal the end of TDMA. Currently, the only country to continue pursuing CDMA implementation, specifically TD-SCDMA, is mainland China to avoid paying loyalty fees to foreign organizations.