A GSM cellular phone is a type of cellular phone that uses the (G)lobal (S)ystem for (M)obile Communications to send and receive phone calls. GSM is a digital standard; first offered commercially in 1991 and is currently the most popular mobile phone transmission technology in the world.

The GSM standard uses TDMA digital technology, which allows for three different voice calls to be placed in the same time slot, rather than one call using the old analog cellular phones. This is possible through digital compression, which GSM then builds upon with the addition of encryption. A GSM cellular phone takes up the same amount of transmission space as the old technology, but has the additional benefit of added security.

One of the great benefits of a GSM cellular phone is the addition of a SIM card, or "Subscriber Identification Module." This little chip slips into the back of a GSM cellular phone and provides all of the users personal information. This includes contacts and calendar information in most cases, and more importantly the subscribers personal identification information. Having this information on a removable chip enables a GSM cellular phone user to move a SIM card between cellular phones and still receive voice calls to the same number. It also prevents user from having to re-input personal information each time a new phone is purchased.

GSM Cellular Phone Advantages
A GSM cellular phone offers superior sound quality. Background sounds, disturbances, and static sounds are vastly reduced; and crossed-line conversations are also almost eliminated in a GSM cellular phone. GSM cellular phone sound quality is more like that of a fixed telephone. The main advantages of a GSM cellular phone are International Roaming ability, good sound quality, small affordable handsets and ability to handle a high volume of users. Unlike analog phones, your conversation using a GSM cellular phone within the digital network is safe and secure.

With superior battery life & digital technology of a GSM cellular phone, you get twice as much talk time from each battery charge, compared with analog phones. In addition, the digital service offered by the GSM cellular phone network, allows more calls to be handled at any one time, therefore reducing congestion in areas of dense population and high usage.

A GSM cellular phone offers roaming facility, which means, you can use your GSM cellular phone, with the same phone number in other countries around the world that operate through the GSM cellular phone network or you can just move your SIM card to another GSM cellular phone.

In Europe and most of Asia, GSM is the standard used by everyone. Having one technology is great, because users can simply move their chips to a different GSM cellular phone if they travel to different countries or in most cases use the same phone. This is in contrast to the US, with so many competing standards and difficulty transferring between carriers.

The adoption of GSM technology and GSM cellular phones as a standard also paved the way for the rise of text messaging in many countries. While text messaging is starting to become popular in North America, it is nowhere near as popular as it is in Europe and Asia. Carriers in the US in particular use various technologies in addition to GSM and must then route text messages through third party gateways. This is how a Sprint user can send a text message to a Verizon customer. Until a few years ago this wasn't possible and served to prevent text messaging from truly catching on.

GSM and GSM cellular phones have found a significant boost due to Cingular Wireless becoming America's largest mobile provider. They have adopted GSM technology and promote the GSM cellular phone's ease of use due to a swappable SIM card. Though the US still has many competing technologies, a GSM cellular phone is the international choice. If you plan to travel frequently overseas, a GSM cellular phone might be a wise decision.

The GSM standard has been around for a relatively long time. Its popularity continues to grow because of the addition of GPRS and integration of cameras, MP3 players and other gadgets into a GSM cellular phone. Modern GSM cellular phones support the creation of text and picture messages. Because of these additions, this relatively old standard is actually being phased in within the US.