Description
The Application Identifier (AID) is a fundamental component in the UICC (Universal Integrated Circuit Card) and SIM card ecosystem, defined by ISO/IEC 7816-4 and adopted by 3GPP for telecommunications applications. An AID consists of two parts: a Registered Application Provider Identifier (RID) and a Proprietary Application Identifier Extension (PIX). The RID is a 5-byte value assigned by ISO to identify the application provider, while the PIX is up to 11 bytes defined by the provider to identify specific applications. This hierarchical structure ensures global uniqueness while allowing providers flexibility in organizing their applications.
In 3GPP systems, AIDs are primarily used to identify the USIM (Universal Subscriber Identity Module) application on UICC cards. The standard AID for USIM is defined as 'A0000000871002FF...' where 'A000000087' identifies the telecommunications industry, '10' indicates the application family (GSM/UMTS applications), and subsequent bytes specify the USIM application. When a mobile device initializes communication with a UICC, it sends a SELECT command with the AID to activate the specific application. The UICC responds with the application's capabilities and available files.
The AID mechanism enables multiple applications to coexist on a single UICC card, including USIM, ISIM (for IMS), and various value-added services. Each application maintains its own file system and security domain, isolated from others. During card personalization, the AID is used to create the application's dedicated file structure. During operation, the terminal uses AIDs to navigate between applications, with the currently selected AID determining which application's files and commands are accessible. This architecture supports the multi-application capability essential for modern UICCs.
Beyond basic identification, AIDs play a critical role in security and application management. They enable secure channel establishment between the terminal and specific applications, with cryptographic keys and security policies associated with each AID. In remote application management (OTA), AIDs are used to target specific applications for updates, enabling operators to modify or add services without physical card replacement. The standardized AID structure ensures interoperability across different card manufacturers, mobile devices, and network operators worldwide.
Purpose & Motivation
The AID was created to solve the fundamental problem of application identification and selection in multi-application smart cards, which became essential as UICC/SIM cards evolved from simple authentication modules to platforms hosting multiple services. Before standardized AIDs, application selection was proprietary and inconsistent, making interoperability between different card manufacturers and mobile devices difficult. The ISO/IEC 7816-4 standard, adopted by 3GPP, provided a universal addressing scheme that enabled the coexistence of telecommunications applications alongside other services on a single card.
As mobile networks evolved from GSM to UMTS and LTE, the need for multiple applications on UICC cards grew significantly. The USIM application for 3G/4G authentication, ISIM for IMS services, and various value-added applications all needed to reside on the same physical card. The AID system provided a standardized way to identify, select, and manage these applications without conflicts. This was particularly important for global roaming, where a subscriber's UICC must work with different network operators' equipment worldwide.
The hierarchical structure of AID (RID + PIX) addressed both global uniqueness requirements and provider flexibility needs. By having ISO manage the RID assignments, conflicts between different application providers were avoided. Meanwhile, the PIX allowed providers to organize their own application families and versions. This balanced approach enabled the explosive growth of UICC-based services while maintaining backward compatibility with existing systems and ensuring future extensibility for new applications.
Classification
Detected Changes Across Releases
from 3GPP Change RequestsSpecific changes extracted from the „Change history“ tables of 3GPP specifications (51 CRs across 5 releases). Complements the general historical overview above with the evidence-based evolution of this function.
Studied in Rel-4, normative work from Rel-15.
In Release 15, the AID function was enhanced to support new 5G services and configurations via the USIM and ISIM. Specifically, updates were introduced to manage Mission Critical Services configuration data, enable PDU session call control support, and allow the configuration of the MCS Access Identity. Additionally, procedures were updated for 5GS and references were clarified for ITS-AID and EFIMSConfigData storage.
- Subscription identifier privacy suppport TS 31.102CR0778
- USIM Service Table update for PDU session call control support TS 31.102CR0786
- Allow configuration of MCS (Access Identity 2) via USIM. TS 31.102CR0794
- Mission Critical Services configuration data update to USIM TS 31.102CR0808
- Enhance USIM OPL configuration to support 3 bytes TAC when in NG-RAN. TS 31.102CR0818
- Updates to USIM management procedures for 5GS TS 31.102CR0806
+ 3 more changes
In Release 16, the AID function was enhanced to support a **Dedicated AID for USIM Applications with non-IMSI based SUPI Types**, allowing for new application identity structures. This was part of broader updates to USIM configuration, including the storage of URSP rules and network lists. The release also introduced clarifications and corrections for application-layer procedures, such as the Link Identifier Update Procedure for V2X communications.
- Support for USIM configuration of RLOS PLMN list TS 31.102CR0847
- URSP storage in USIM TS 31.102CR0861
- Specify storage for a potentially separate KSEAF for non-3gpp access on the USIM TS 31.102CR0864
- USIM configuration of RLOS allowed MCC list TS 31.102CR0881
- Support for Trusted non-3GPP access networks list by USIM TS 31.102CR0891
- Add VAE application requirement notification TS 23.286CR0013
+ 14 more changes
In Release 17, the AID (Application Identifier) function itself was not directly modified according to the provided context. The release introduced several new USIM configuration files for network and service management, such as for storing pre-configured CAG information, disaster roaming parameters, eDRX settings for NG-RAN, and 5G NSWO configuration. These additions expand the USIM's role in storing application-related configuration data but do not specify changes to the fundamental AID structure or its use as the entry point to an application on the UICC.
- V2X application layer architecture enhancement TS 23.286CR0022
- Updates to usage of SEAL for V2X application layer TS 23.286CR0064
- Introduce a USIM file to store pre-configured CAG information list TS 31.102CR0904
- SOR-CMCI storage in USIM TS 31.102CR0917
- Addition of USIM files for the indication of whether disaster roaming is enabled in the UE, disaster roaming wait range, disaster return wait range and applicability indicator for disaster roaming PLMNs list provided by VPLMN. TS 31.102CR0938
- Adding eDRX parameters in the USIM for NG-RAN TS 31.102CR0943
+ 6 more changes
In Release 18, the AID function was expanded to support new application-specific configuration files on the USIM and ISIM. Specifically, this included adding Elementary Files (EFs) for IMS Data Channel configuration and for Access Control to GBA_U_APIs. These updates enhanced the UICC's role in securely storing and managing application parameters for services like IMS and Generic Bootstrapping Architecture.
- V2X application layer architecture support for edge deployments TS 23.286CR0072
- 5G Security Parameters extended storage on USIM (Mandating Service n°133 to be enabled when Service n°123 is enabled) Rel18. TS 31.102CR1014
- Add EF of Access Control to GBA_U_APIs to the USIM TS 31.102CR1007
- Add EF of IMS Data Channel configuration to the USIM TS 31.102CR1006
- Correction of DF Identifier for 5MBSUECONFIG TS 31.102CR0984
- Test cases and sources correction related to coverage of GBAUCipher class from uicc.usim.gba_u TS 31.213CR0053
+ 3 more changes
In Release 19, the enhancement for the Application Identifier (AID) function specifically addressed backward compatibility for the USIM application. This was achieved by defining handling procedures for USIMs that lack extended security parameter storage, such as within the EF_5GAuthKeys file. This ensures that new network authentication features remain functional even with legacy UICC cards that have limited storage capabilities.
- Backward compatibility handling of USIM without extended security parameter storage in EF_5GAuthKeys - Rel19 TS 31.102CR1074
Explore further
Broader topics and technologies where AID plays a role.
Defining Specifications
3GPP specifications that define or reference AID, with the latest known release. Sourced from the 3GPP document catalog — see methodology.
| Specification | Title | Release |
|---|---|---|
| TR 21.905 vj00 | 3GPP Technical Terms and Definitions | Rel-19 |
| TS 23.285 vj00 | V2X Architecture Enhancements for LTE | Rel-19 |
| TS 23.286 vj00 | V2X Application Enabler Architecture | Rel-19 |
| TS 23.287 vj00 | 5G V2X Architecture Enhancements | Rel-19 |
| TS 31.102 vj40 | USIM Application Specification | Rel-19 |
| TS 31.103 vj00 | ISIM Application Specification | Rel-19 |
| TS 31.105 vj10 | Slice Subscriber Identity Module (SSIM) Application | Rel-19 |
| TS 31.213 vi30 | Test specification for (U)SIM | Rel-18 |
| TR 31.822 vi10 | Technical Report on GBA_U based APIs | Rel-18 |
| TS 31.829 vd00 | ISIM Conformance Requirements Technical Report | Rel-13 |
| TS 34.131 vj00 | SIM API C Language Test Specification | Rel-19 |
| TS 51.013 vj00 | SIM API for Java Card Test Specification | Rel-19 |