SIM Cards

In this day and age of technology almost all people carry around cell phones. They have become a necessity for most people and everyone has come to know the cell phone as a main staple of their life. However, most people take for granted what their cell phones do for them and they underestimate the amount of important information about their lives contained on the phone. And it is when one breaks their phone, as most veteran cell phone owners have done, that one realizes exactly how helpless they are without the information that was stored on their phone; information that is necessary for our day to day functions. Luckily, many cell phone companies use a technology that is both a data storage device and a cell phone’s identity, all in one small package.

A Subscriber Identity Module card, or SIM card, is a data storage device that fits inside the battery compartment of a cell phone. Holding between 16 kb to 512 kb of information on a size 15 by 25 mm card, the SIM card can store a lot of information. The main point of a SIM card is to eliminate the need to activate cell phones for a user. The cell phone company stores the numbers that are needed to make a phone work on the card, so that a user can switch SIM cards in phones and still use the same number.

Going one step further is the JAVA software that is installed on the card. This allows other data from the cell phone to be temporarily stored. Things such as numbers and text messages can be stored on the SIM card. Because of this, when you transfer a SIM card from one phone to another, the contacts are transferred as well. This is extremely useful to many when one cell phone dies. No longer do we have to wait for people to call us so we can get their number again. The SIM card takes care of all that, and also saves you a trip to your provider.

http://en.wikipedia.org/wiki/Subscriber_Identity_Module

http://www.planetomni.com/FAQ_sim.shtml

http://reviews.cnet.com/4520-10166_7-6160666-1.html

-Mike-