INTRODUCTION

The Global System for Mobile communications (GSM) network is the wireless standard chosen by some 170 countries around the world as the system of choice for digital wireless communications. This standard operates predominantly on the 900 and 1800 MHz frequency and is employed in most parts of Europe, Asia, Africa, and Australia (see coverage for more information).

GSM has rapidly become the most widely accepted and adopted wireless standard in the world. It now accounts for over 70% of the globe's cellular market. Particular coverage may vary slightly depending upon the service provider chosen by the subscriber. [It is also employed in North America and parts of South America on the 1900 MHz frequency standard.]

SIM CARD

The single most distinguishable feature of GSM is the Subscriber Identification Module card, commonly referred to as a SIM card.

A SIM card appears similar to a credit card (or a small chip) but has an embedded microchip. The user's service provider programs the microchip on the SIM card with the subscriber's U.S. wireless number, optional features, and billing information. The SIM card must be inserted into a GSM mobile handset to access the available network. The SIM card then carries all the information needed for the activation and validation of the handset. While traveling abroad to any covered region, subscribers can make or receive local, long distance, and international calls just the way they would at home using their US wireless number.

The charges for all calls made and received on the GSM phone are then consolidated on the subscriber's domestic cellular bill.

The first generation of cellular service is generally considered to be the analog systems that operate on the Advanced Mobile Phone System (AMPS) standard.

Digital systems that employ Time Division Multiple Access (TDMA) technology are generally considered second generation. TDMA networks have approximately three times the capacity of a similar AMPS network. Third generation cellular networks are also digital but use another access technology to allocate the available spectrum to end-users. With Code Division Multiple Access (CDMA) technology, all users can share the entire spectrum because each user's conversation is differentiated by a unique digital code. Because the entire spectrum can be re-used by other users, CDMA networks have approximately 8 to 10 times the capacity of a similar AMPS network. Neither TDMA nor CDMA, however allows international roaming using the same handset.

GSM is vastly different from the above standards. GSM is an all digital standard. From the consumer's point of view, this means less static, clearer reception and overall better audio quality. Also, due to the use of digital codes, cloning is not an issue with GSM phones. Additional services such as data transmission and short messaging service (SMS) can be offered on a GSM network (depending on the carrier).

Now out of the country does not have to mean out of touch! ™