Saturday, 21 July 2012

SIM cards

Cell phones used to be something that only rich people had. Today they aren't just a luxury or something for emergencies. People carry them around everywhere and people of all ages have them. Some are designed for very young children so they can call their parents and emergency numbers. May of us take out cell phones for granted and never stop to consider how they work.

One of the most important elements of any cell phone is the SIM card. SIM stands for Subscriber Identity Module. This is what allows the various types of information to be stored in there. This type of information includes the phone numbers, list of names, ringtones, and other information you have in there. Many people use their cell phone to be able to set reminders as well for appointments.

SIM cards can also help law enforcement agencies to track down the owners of various cell phones. This can be important to their investigation if they are trying to determine where certain phone calls have come from. Since there is really no directory out there of cell phone numbers many people think they are completely anonymous. Yet if you are doing something illegal law enforcement can use their access to find out about cell phone use from SIM cards.

A SIM card is made up of a code of 19 numbers. All of the numbers on that code are for a specific purpose. The first two numbers will identify the ID of the company marketing the cell phone. The next two are for the country. The next two cover the network that the cell phone belongs to. There are four numbers that will identify the month and the year that the SIM card was made. These are followed by two numbers that are a configuration code. Seven digits remain with the first six being the SIM number and the last one being a check digit.

If you are going to upgrading to a new cell phone you should ask about having your SIM card information transferred. This can often be done before the service is completely shut off on the old phone. If you don't do this you will lose all of the data you had stored on your old cell phone. Many people end up having to write it all down manually and then programming it into their new phone because they don't realize that the SIM card has all of that information readily available for them to access.