Introduction to SIM Application Toolkit
The SIM Application Toolkit, commonly known as STK, is a standard of the GSM system that allows subscribing identity module (SIM Card) to take action for several value-added services.
There are some similar standards that exist for other network and card systems with the USIM Application Toolkit (USAT) for USIMs that can be used by newer-generation networks.
There is one more name for this class of Java Card-based applications that are running on UICC cards is the Card Application Toolkit.
The STK includes a set of commands programmed into the SIM that enables us to understand how the SIM should communicate directly with the outside world as well as initiate commands independently of the handset as well as the network.
It also allows the SIM to create an interactive exchange between a network application as well as the end-user and access, or control access to, the network.
Then, the SIM can give the command to the device or the handset, such as displaying menus and/or asking for user input.
It is designed as a single application environment that can be started during the initial power-up of the SIM card. It can be suited to low-level applications along with simple user interfaces.
When it comes to GSM networks, the STK is defined by the GSM 11.14 standard released in the year 2001. From release four onwards, it was replaced by 3GPP TS 31.111 that comes with the specifications of the USIM application toolkit for 3/4G networks.
Top Advantages of SIM Application Toolkit
- There are many manufacturers that claim that STK comes with a higher level of security via identity verification and encryption, which are important for secure electronic commerce.
- SIM application toolkit has been deployed on the largest number of mobile phones.
Updating android software can be performed over GSM in which the SIM Toolkit may install automatically with new software regardless of automatic install applications.
Changes in applications, as well as menus stored on the SIM, are tough after the customer takes delivery of the SIM and in many cases may be recognized as surveillance software.
To provide updates, either the SIM should be returned and exchanged for a new SIM or the application updates should be delivered over-the-air (OTA) with the help of specialized, optional SIM features.
In October 2010, mobile network operators delivered STK application menus by sending a secure SMS to mobile devices; the updates are delivered quickly as well.
It also becomes possible to change the menu of STK applications on the basis of the Wireless Internet Gateway specifications. The updates limitations hinder the number as well as frequencies of STK application deployments.
- SIM Application Toolkit comes with no support for multimedia. It only supports basic images.
- SIM Application Toolkit comes with limited independent development support available.
In Newer Networks
USIM Application Toolkit, commonly known as USAT, is the equivalent of STK for 3G networks. It takes advantage of the multi-application environment of 3G devices to not activate until a specific application has been selected, unlike STK, that is activated at startup.
Some of these functions are care-related instead of application-related. In addition to this, SIM Application Toolkit will continue to be the strongest and powerful value-added service technology for mobile services over the years to come.