Question: In CELL_FACH state with DRX, when using absolute priority based reselection, what triggers a UE to search for all inter-frequency layers?
Option 1: When SrxlevServingCell > Sprioritysearch1 and SqualServingCell > Sprioritysearch2
Option 2: Allocation of E-DCH resources to the UE
Option 3: When SrxlevServingCell <= Sprioritysearch1 or SqualServingCell <= Sprioritysearch2
Option 4: Expiration of timer T321
Explanation: According to the rules for absolute priority based reselection in CELL_FACH state with DRX, a UE searches for all inter-frequency layers when the serving cell's signal level (Srxlev) or quality (Squal) falls below certain thresholds (Sprioritysearch1 and Sprioritysearch2). This ensures the UE seeks better service conditions when its current connection is below these predefined standards.