Design
There are three operating voltages for SIM cards: 5 V, 3 V and 1.8 V (ISO/IEC 7816-3 classes A, B and C, respectively). 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. Modern cards support 5 V, 3 V and 1.8 V.
The microcontrollers used for SIM cards come in different configurations. The typical ROM size is between 64 KB and 512 KB, typical RAM size is between 1 KB and 8 KB, and typical EEPROM size is between 16 KB and 512 KB. The ROM contains the operating system of the card and might contain applets where the EEPROM contains the so-called personalisation, which consists of security keys, phone book, SMS settings, etc., and operating system patches.
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, which was initially specified by ETSI in TS 11.14. SIM toolkit applications were initially written in native code using proprietary APIs. In order to allow interoperability of the applications, Java Card was taken as the solution of choice by ETSI.
Read more about this topic: Subscriber Identity Module
Famous quotes containing the word design:
“If I commit suicide, it will not be to destroy myself but to put myself back together again. Suicide will be for me only one means of violently reconquering myself, of brutally invading my being, of anticipating the unpredictable approaches of God. By suicide, I reintroduce my design in nature, I shall for the first time give things the shape of my will.”
—Antonin Artaud (1896–1948)
“With wonderful art he grinds into paint for his picture all his moods and experiences, so that all his forces may be brought to the encounter. Apparently writing without a particular design or responsibility, setting down his soliloquies from time to time, taking advantage of all his humors, when at length the hour comes to declare himself, he puts down in plain English, without quotation marks, what he, Thomas Carlyle, is ready to defend in the face of the world.”
—Henry David Thoreau (1817–1862)
“The reason American cars don’t sell anymore is that they have forgotten how to design the American Dream. What does it matter if you buy a car today or six months from now, because cars are not beautiful. That’s why the American auto industry is in trouble: no design, no desire.”
—Karl Lagerfeld (b. 1938)