Know about SIM card | SIM used in Mobile phone

• published: 23 Jan 2015
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Subscribe us https://www.youtube.com/channel/UCL0Rx2AaUwomAe3FGKtgCBA Know about SIM Card Introduction SIM stands for subscriber identity module or subscriber identification module, is an integrated circuit that securely stores the international mobile subscriber identity (IMSI) and the related key used to identify and authenticate subscribers on mobile telephony devices. It also contains its unique serial number (ICCID), security authentication and ciphering information, temporary information related to the local network. History The first SIM card was made in 1991 by Munich smart-card maker Giesecke & Devrient. The SIM was initially specified by the European Telecommunications Standards Institute in the specification with the number TS 11.11. This specification describes the physical and logical behaviour of the SIM. With the development of UMTS the specification work was partially transferred to 3GPP. Design Modern SIM cards allow applications to be loaded when the SIM is in use by the subscriber. These applications communicate with the handset or a server using SIM application toolkit. The operating voltage of the majority of SIM cards launched before 1998 was 5 V. SIM cards produced subsequently are compatible with 3 V and 5 V. Formats SIM cards have been made smaller over the years, functionality is independent of format. Full-size SIMs were followed by mini-SIMs, micro-SIMs, and nano-SIMs. Full size SIM has the size of a credit card (85.60 mm × 53.98 mm × 0.76 mm). The mini-SIM card has the same contact arrangement as the full-size SIM card and is normally supplied within a full-size card carrier, attached by a number of linking pieces. The micro-SIM was designed for backward compatibility. The major issue for backward compatibility was the contact area of the chip. Retaining the same contact area allows the micro-SIM to be compatible with the prior, larger SIM readers through the use of plastic cutout surrounds. The SIM was also designed to run at the same speed (5 MHz) as the prior version. The nano-SIM card was introduced on 11 October 2012, when mobile service providers began selling it in various countries. The nano-SIM' measures 12.3 × 8.8 × 0.67 mm and reduces the previous format to the contact area while maintaining the existing contact arrangements. A small rim of isolating material is left around the contact area to avoid short circuits with the socket. The 0.67 mm thickness of the nano-SIM is about 12% less than the 0.76 mm of its predecessor. SIM and carriers The SIM card introduced a new and significant business opportunity for MVNOs — mobile virtual network operators — who lease capacity from one of the network operators rather than owning or operating a cellular telecoms network, and only provide a SIM card to their customers.