Question: In a USIM application, what is the primary purpose of the EFPURI (Phonebook URIs) Elementary File (EF), and how are its records structured in relation to EFADN?
Option 1: To store multiple phone numbers per contact, with each EFPURI record containing only a URI address, shared across multiple EFADN entries.
Option 2: To link URI addresses to specific phonebook entries, where each EFPURI record contains both a unique URI address and a reference (SFI and Record Identifier) to one associated EFADN record.
Option 3: To manage email addresses for contacts, with the structure including only a URI part without any direct linkage to EFADN records.
Option 4: To store social media profiles for phonebook entries, using a coding scheme different from both EFIMPU and EFADN standards.
Explanation: The correct answer is Option 2 because the EFPURI's primary function is to associate URI addresses with specific phonebook entries in EFADN. Each EFPURI record is uniquely linked to one EFADN record through its structure, which includes both the URI address and a reference (Short File Identifier - SFI, and Record Identifier) to the associated EFADN entry, ensuring a one-to-one correspondence that cannot be shared among multiple phonebook entries. This setup facilitates organized and distinct storage of additional contact information (like URIs) tied to individual phonebook contacts.