GSM

ALSO CALLED: Global System for Mobile Communication, GSM Wireless
DEFINITION: A SIM card, also known as a subscriber identity module, is a smart cardthat stores data for GSMcellulartelephone subscribers. Such data includes user identity, location and phone number, networkauthorization data, personal security keys, contact lists and stored text messages. Securityfeatures include authenticationand encryptionto protect data and prevent eavesdropping.A SIM card and can be switched  … 
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GSM DEFINITION (continued): …  easily from one phone set to another. The portability of dataoffers a number of benefits. For example, a user that buys a new phone can install the current SIMcard to associate the new phone with the same number and user preferences as the old one. Inanother common situation, if a phone's battery runs out of power, the user can easily install thecard to another subscriber's phone to borrow it without running up that user's minutes. Somevendors offer prepaid SIM cards that can provide travelers with local numbers, as long as theircell phones are not locked to a specific carrier.A device called … 
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