Question: In UTRAN Iu interface RANAP signalling, when tracing UEs based on an Equipment Identity mask, what determines which digits of the IMEI/IMEISV are matched exactly for grouping?
Option 1: The state of the corresponding bit in the IMEI/IMEISV Mask IE (1 indicates a match is required for those digits)
Option 2: The type of Equipment Identity used (IMEI vs. IMEISV) dictates fixed positions for exact matching
Option 3: A predefined set of digits (e.g., always the first 4 and last 2 digits) are matched exactly regardless of the mask
Option 4: The RNC's tracing configuration, which can dynamically alter the masking logic
Explanation: According to RANAP signalling specifications for tracing UEs, the IMEI/IMEISV Mask IE determines which digits must match exactly. Each bit in this mask corresponds to specific digit positions; a set bit (1) indicates the corresponding digits in the UE's IMEI or IMEISV must be identical for grouping.