Context:
Understanding the components of a SIM card, its functions and working | Building blocks | The Hindu
Key Details – SIM card
What is a SIM card?
- ‘SIM’ stands for ‘subscriber identification module’.
- It is an integrated circuit, or a microchip, that identifies the subscriber on a given network.
- Each cellular network has subscribers who are identified by a number, called the international mobile subscriber identity (IMSI).
Why a SIM card is mandatory for connection?
- A SIM card is mandatory in order for a mobile phone to connect to any cellular network that follows the Global System for Mobile Communications (GSM) standard.
- This relationship is established using a unique authentication key — a piece of data that a user needs to ‘unlock’ access to the network.
What does the SIM card store?
- Every SIM card stores this data and it is designed such that the user can’t access it through their phone.
- Instead, signals sent by the phone into the network are ‘signed’ by the key, and the network uses the signature to understand whether the phone’s connection is legitimate.
- It also stores own ID number (the integrated circuit card identifier), the IMSI, the subscriber’s location area identity, a list of preferred networks etc.
What are the specifications?
- They are designed according to the ISO/IEC 7816 international standard maintained by the International Organisation for Standardisation and the International Electrotechnical Commission.
- SIM card consists of the integrated circuit, silicon substrate, metal contacts.
- The size and architecture of this microchip evolved in leaps and bounds in the subsequent decades, following Moore’s law.
How has a SIM card evolved?
- European Telecommunications Standards Institute (ETSI) prepared the GSM Technical Specification 11.11 regarding the SIM card.
- It defines interface between the SIM and the Mobile Equipment (ME), operating temperature and “contact pressure” etc.
- ETSI transferred some of its responsibilities to an international consortium of seven organisations called 3GPP (e.g. Telecommunications Standards Development Society in India).
- 3GPP subsequently developed the standards for the third (3G), fourth (4G), and fifth generation (5G) of networks.
- The term ‘SIM card’ denoted both the hardware and the corresponding software until 2G.
- From 3G networks, ‘SIM’ became only the software and the hardware was called the Universal Integrated Circuit Card (UICC).
- The software was also upgraded to an application called Universal SIM (USIM).
What is an eSIM?
- SIM software is loaded on to a UICC that is permanently installed in the mobile equipment in the factory itself, that it can’t be removed. This is called the eUICC.
- Advantages –
- Environmentally friendlier than a physical SIM
- Reprogrammability (no need for more plastic and metal for a new SIM)
- No malicious person can be able to separately access the SIM application nor be able to duplicate it.
- Disadvantages –
- eSIMs can be programmed by subscribers themselves.
- eSIM can allow network operators to track subscribers’ data.
Source: The Hindu
Previous Year Question
With reference to Web 3.0, consider the following statements:
1. Web 3.0 technology enables people to control their own data.
2. In Web 3.0 world, there can blockchain based social networks.
3. Web 3.0 is operated by users collectively rather than a corporation.
Which of the statements given above are correct?
[UPSC Civil Services Exam – 2022 Prelims]
(a) 1 and 2 only
(b) 2 and 3 only
(c) 1 and 3 only
(d) 1, 2 and 3
Answer: (d)
