Gsm Phones - Accessories And Information

Written by Helen Glenn Court
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In some respects Silicon Valley achievements are astounding and admirable, but in others--such as cell phone technology, specifically, GSM phones--the valley's so behind the eight ball it ought to put the cue stick back in the rack and go home for a spell. GSM is now an acronym for global system mobile communications technology.

GSM is also the world's leading cell phone standard. Developed in Europe, when the acronym still meant Groupe Spéciale Mobile, the technology spread quickly to Africa, Asia, and the Pacific Rim. It came to America only about 10 years later. GSM phones in the United States operate on the same (basic) principle as almost all others in the world but at a different frequency.

The Evolution of GSM Phones

From 1978 to 1987 mobile communications in the United States were analog, which works very much like a radio. Both transmitter and receiver are tuned to the same frequency and the number of users is limited. This inefficiency led to digital technology (GSM phones are digital). In digital wireless, analog voice signals are converted to binary code. There are three digital technologies--TDMA, GSM, and CDMA.

After a 1987 Federal Communications Commission ruling, cell phone technology in the United States was left to develop along any technology service providers wished. TDMA, which means time division multiple access, was released in 1994 (AT&T and Cingular). GSM, which is based on a marriage of TDMA and analog, offering 200 channels instead of 30, and each channel with eight rather than three slots, was released in 1995 (Cingular, T-Mobile, and AT&T). CDMA, which means code division multiple access, was released in 1996 (Sprint and Verizon). All wireless in the United States uses either the 800/850 MHz or the 1900 MHz frequency channel, or both.

In Europe, however, the concept and consensus on wireless had developed earlier, by 1985. A unified system for a wireless network was planned from the start. The advantages of digital over analog were recognized immediately--excellent sound quality, high security, and data capability. The technology, along with the 900 and 1800 MHz frequencies, was used as the standard from the get-go. GSM phones are the only wireless technology outside of the United States and a few South American countries.

GSM Phones in America

Another key difference in GSM technology in America and the rest of the world is the link between customer and service provider. In America the service is hard coded into the phone. When you switch providers, you're forced to buy a new phone. Elsewhere, service comes from a removable tiny circuit board--SIM, or subscriber identification module. When you subscribe for wireless service, the company gives you a SIM to pop into your phone.

GSM phones in the United States not only operate on a different frequency than most others in the world, but also are not even the standard technology in America or the precise same technology as in Europe or Asia. What this means is that there's a 99 percent chance that your cell phone is next to useless when you travel abroad. If you're willing to pay from $1 to $7 a minute for a wireless phone connection, however, you can usually get service.

Most wireless phones in the United States are either TDMA or CDMA. Bare bones phones cost very little. In shopping for GSM phones, you'll see several terms describing their technology--hybrid, dual band, tri-band, quad-band, and world--and be paying for the added technology. Costs soar. Expect prices as high as $800 down to $250, rather than the $100 or $50 or free phone you get with a two-year plan. Your best bet is for a tri-band that covers 900, 1800, and 1900 MHz, which will give you the best geographical coverage worldwide.


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