The three sim cards or Subscriber Identity Module is an old acquaintance of mobile telephone. It's a little plastic card with a processor that securely stores the telephone number and access codes for a specific user at a telephone owner.
Designed in the 70s, the technology of smart cards or smart card had numerous uses until, in early 90s, was included as a required identification of customers on the networks of mobile GSM. The processor of a Simulator has ten electrical contacts that allow you to interact with the telephone where it's placed. Over time, in addition to user validation data within the network, the cards SIM have expanded their initial 16KB capacity to save more information from your data including internet link or a simple plan.
Although I have the cryptographic and security method was overcome, the use of the Simulator is pervasive networks both GSM and CDMA, even though in the latter format is somewhat different and is called R - UIM. More than security, Sim card gives the convenience of keeping user information in a physical environment that can be moved readily from one to another exchangeable mobile.
Initially, the SIM was the size of a bank card. To fit it into a iphone standard established the MiniSim or GSM SIM through a die 15 25 mm. This common is generally recognized now as Simulator, but actually was not the very first. In 2003, the ETSI (European Telecommunications Standards Institute) produced the Mini- UICC, better known as MicroSIM. The goal was to enlarge the memory MicroSIM and improve system security. Also further cut the plastic until it's in nearly the dimensions of the connection, 12 15 mm. With this change, the ETSI aimed at creating an appropriate structure for very small devices. The GSMA, yet, failed to support the format MicroSIM and remained in the background until The apple company decided they would integrate it in to your iPad. The recognition of this device pushed MicroSIM format. You will be in smartphones from other programs and exists as an alternative for nearly all providers.