SIM

In terms of 'sales' the (Subscriber Identity Module) SIM or better the USIM, how it is called since 3G, must rank as ETSI's most successful standard. There are several billions of USIMs sold every year in the world and no sign of a slowdown in the demand for them. The SIM has developed in to a 'Smart Secure Element' with a growing variety of applications and features.

The USIM used in Digital Cellular Telecommunications Systems like from GSM over 3G, 4G now to 5G is the entity that contains the identity of the subscriber. When the SIM is placed in a terminal or handset, users can register onto a network.

The primary function of the USIM is to authenticate the validity of a terminal when accessing the network. It also provides a means to authenticate the user and may also store other subscriber-related information or applications.

The ETSI work on Secure Elements, namely the evolvement of the functionality of the UICC, which is the basic platform for the USIM has evolved the USIM, towards allowing contact-less data flow for Identity, Security and Payment applications.

USIM standardization is concentrated in two committees:

3GPP-CT6

Technical Specifications Group, 'Core Network and Terminals' Working Group 6 (CT WG6) is responsible for the specifications of network authentication applications such as the Subscriber Identity Module (SIM) which is used by 2G systems, the USIM (Universal Subscriber Identity Module) which is used by 3GPP™ systems  (from 3G to 5G), the ISIM (IM Services Identity Module) for authenticating to IMS and the HPSIM (Hosting Party Subscription Identity Module) with the exception of the security algorithms (developed by 3GPP™ Systems Aspects (SA) WG3).

The group is responsible for the standardization of the USIM/SIM for applications on top of the UICC specified by ETSI TC SET.

See http://www.3gpp.org/specifications-groups/ct/wg6.

ETSI technical committee Secure Element Technologies (SET)

The Committee is responsible for the definition of the Secure Element Platform, the UICC.

USIM listing

The Universal Subscriber Identity Module (USIM) is a 3GPP application on the UICC. It interoperates with a 3GPP terminal and provides access to 3GPP services.

The USIM application for 3GPP telecom network operation defines:

• specific command parameters;
• file structures;
• contents of EFs (Elementary Files);
• security functions;
• application protocol to be used on the interface between UICC (USIM) and ME.

In addition 3GPP™ defines the interface between the UICC and the Mobile Equipment and procedures for the USIM Application Toolkit (USAT):

• the commands;
• the application protocol;
• the mandatory requirements on the UICC and ME for each procedure.

UICC listing

3GPP™ specifies the interface between the UICC and the Terminal for 3GPP telecom network operation, which includes:

• the requirements for the physical characteristics of the UICC;
• the electrical interface between the UICC and the Terminal;
• the initial communication establishment and the transport protocols;
• the model which serves as a basis for the logical structure of the UICC;
• the communication commands and the procedures;
• the application independent files and protocols.

3GPP TSG CT WG6 is mainly referring to the specifications developed by ETSI TC SET for the UICC. However, 3GPP TSG CT WG6 is defining specific deviations or additions on top of the UICC specifications developed by ETSI TC SET.

ETSI TC SET specifies the interface between the UICC and the terminal in general, such as:

• the requirements for the physical characteristics of the UICC;
• the electrical interface between the UICC and the terminal;
• the initial communication establishment and the transport protocols;
• the model which serves as a basis for the logical structure of the UICC;
• the communication commands and the procedures;
• the application independent files and protocols.

ISIM listing

The specification of the IP Multimedia Services Identity Module (ISIM) application for access to IMS services contains:

• specific command parameters;
• file structures;
• contents of EFs (Elementary Files);
• security functions;
• application protocol to be used on the interface between UICC (HPSIM) and Terminal.

This is to ensure interoperability between an ISIM and Terminal independent from the respective manufacturer, card issuer or operator.

HPSIM listing

The specification of the Hosting Party Subscription Identity Module (HPSIM) application for access to Hosting Party services by a H(e)NBcontains:

• specific command parameters;
• file structures;
• contents of EFs (Elementary Files);
• security functions;
• application protocol to be used on the interface between UICC (ISIM) and Terminal.

SSIM listing

The specification of the Slice Subscriber Identity Module (SSIM) application for 3GPP telecom network operation related to optional Network Slice-Specific Authentication and Authorization procedure:

• specific command parameters;
• file structures;
• contents of EFs (Elementary Files);
• security functions;
• application protocol to be used on the interface between UICC (SSIM) and ME.

Contactless interface

The specification defines a radio frequency-independent interface between the UICC and a contactless function (CLF) component in the terminal. This interface allows the card to be in use, even when the terminal is switched off for telecommunications use.

The ETSI SET specification specifies the interface between the UICC and the CLF component based on a single wire protocol (SWP).