SIM card or Subscriber Identity Module is a portable memory chip that is inserted in cellular phones. It is like a tiny hard disk that automatically activates the cell phone when inserted. The SIM contains such information as personal identity of the cell owner, cell phone number, text messages, phone book, and other information. A SIM serial number is a unique identification number assigned to each SIM card. It is a 19-digit number found on the back of the card. Users need this number for the activation process. When switching to a new cell phone, the user just has to take the SIM card out of the old phone and insert it in the new phone.

To create a standard for a mobile telephone system that could be used across Europe, in 1982, the European Conference of Postal and Telecommunications Administrations (CEPT) created the Groupe Special Mobile (GSM). In 1987, a memorandum of understanding was signed by 13 countries to develop a common cellular telephone system across Europe. Led by Torleiv Maseng, the cellular phone system was created by SINTEF. Also in 1987, the release of mobile phones in Germany, C-Netz, included a card with a chip referred to as a “smart card.” This greatly boosted its capacity and increased its popularity.

In 1989, the responsibilities of the GSM were transferred to the European Telecommunications Standards Institute (ETSI). In 1991 the first GSM network was launched by Radiolinja in Finland with joint technical infrastructure maintenance from Ericsson. By the end of 1993, there were over one million subscribers using GSM phone networks. At the time, 70 carriers across 48 countries were in place.

In 1993, Telecom Australia deployed a GSM network outside of Europe and the first hand-held GSM mobile phone was released. In 1995, data, fax, and SMS messaging services became commercially available. The first 1900 MHz GSM network became operational in the US. In 1996, pre-paid GSM SIM cards were launched. In 1998, GSM subscribers surpassed 100 million.

In 2000, the first commercial GPRS services were launched. In addition, the first GPRS compatible handsets were released. In 2002, the first multimedia messaging services (MMS) were introduced. Also, the first GSM network in 800 MHz frequency band became operational. A CDMA SIM card called the R-UIM or Re-Useable Identification Module was made available in China in 2002. It will eventually be available across the globe. In 2004, GSM subscribers exceeded 1 billion worldwide.

By 2005, GSM networks covered more than 75% of the global cellular network market. There were over 1.5 billion subscribers. In 2007, the launch of the first HSUPA network took place. In the next four years, by 2008, GSM subscribers doubled and exceeded 2 billion worldwide.

So, SIM the portable memory chip that is inserted in cellular phones and activates the cell phone when inserted, in less than 25 years, has evolved to worldwide use. Containing such vital information as the phone number and the carrier that provides the card and rates, the SIM card is the heart of the cell phone. Perhaps best of all is that when traveling abroad, you can get international SIM cards to make roaming charges much cheaper.

Save on long distance roaming charges with a global sim card from Brightroam. International sim card drastically reduce the amount of roaming charges on your phone bill!

Save on long distance roaming charges with an international SIM card from Brightroam. International SIM cards drastically reduce the amount of roaming charges on your phone bill!
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Author Bio: Save on long distance roaming charges with a global sim card from Brightroam. International sim card drastically reduce the amount of roaming charges on your phone bill!

Category: Computers and Technology
Keywords: Sim cards, Sim card, international cell phone, international SIM card, global phone