From Wikipedia, the free encyclopedia

SIM Application Toolkit (commonly referred to as STK) is a standard of the GSM system which enables the SIM to initiate actions ^[1] which can be used for various value added services.^[2]

The SIM Application Toolkit consists of a set of commands programmed into the SIM card which define how the SIM should interact directly with the outside world and initiates commands independently of the handset and the network.^[3] This enables the SIM to build up an interactive exchange between a network application and the end user and access or control access to the network.^[4] The SIM also gives commands to the handset, such as display menu and ask for user input.^[5][6]

STK has been deployed by many mobile operators around the world for many applications, often where a menu-based approach is required, such as mobile banking and content browsing.^[7][8] Designed as a single application environment, STK can be started at the initial power up of the SIM card ^[9] and is especially suited to low level applications with simple user interfaces.^[10]

In GSM 2G networks SIM Application Toolkit is defined in the GSM 11.14 standard in 1995.^{[11][12] [13]}

• Some manufacturers claim that STK enables higher levels of security through identity verification and encryption, which are necessary for secure electronic commerce.^[14][15][16]
• STK has been deployed on the largest number of mobile devices.^[17]

• After a SIM has been delivered to the customer it can be difficult to change the STK applications and menus on the SIM. To do so either the SIM must be returned and exchanged for a new one which is costly and inconvenient or in some cases the applications can be updated over the air.^[18][19] This limitation hinders the number and frequency of STK application deployment.^[20]
• No multimedia support (only basic pictures)^[21]
• Poor independent development support^[22]

USIM Application Toolkit (USAT) is the equivalent of STK for 3G networks.^[23]

1. ^ http://www.ec-mobile.ust.hk/mobile/toolkit.htm
2. ^ http://www.cellular.co.za/sim_toolkit.htm
3. ^ http://www.gemplus.com/techno/stk/
4. ^ http://www.cellular.co.za/sim_toolkit.htm
5. ^ http://www.gsmmobile.co.nz/Sim_Toolkit.htm
6. ^ http://www.3gpp.org/ftp/tsg_t/WG3_USIM/TSGT3_10/docs/t3-99346.doc
7. ^ http://www.ec-mobile.ust.hk/mobile/toolkit.htm
8. ^ http://www.cellular.co.za/sim_toolkit.htm
9. ^ http://www.3gpp.org/ftp/tsg_t/WG3_USIM/TSGT3_10/docs/t3-99346.doc
10. ^ http://www.gsmmobile.co.nz/Sim_Toolkit.htm
11. ^ http://www.gemplus.com/techno/stk/
12. ^ http://www.cellular.co.za/sim_toolkit.htm
13. ^ http://www.gsmmobile.co.nz/Sim_Toolkit.htm
14. ^ http://www.ec-mobile.ust.hk/mobile/toolkit.htm
15. ^ http://bladox.com/devel-docs/gen_stk.html
16. ^ http://www.gsmmobile.co.nz/Sim_Toolkit.htm
17. ^ http://bladox.com/devel-docs/gen_stk.html
18. ^ www.gemplus.com/press/archives/2004/telecom/15-06-2004-ota_saudi.html
19. ^ http://www.smartcardalliance.org/industry_news/industry_news_item.cfm%3FitemID%3D357
20. ^ http://www.mygemplus.com/pss/telecom/download/GemConnect_online_sdk.pdf
21. ^ http://bladox.com/devel-docs/gen_stk.html
22. ^ http://bladox.com/devel-docs/gen_stk.html
23. ^ http://www.gemplus.com/techno/stk/