Question: Where are EPS security context parameters stored if the corresponding file is not present on the Universal Subscriber Identity Module (USIM)?
Option 1: In a volatile memory within the User Equipment (UE)
Option 2: In a non-volatile memory in the Mobile Equipment (ME) along with the International Mobile Subscriber Identity (IMSI) from the USIM
Option 3: Directly on the E-UTRAN (Evolved Universal Terrestrial Radio Access Network) server
Option 4: Exclusively on a removable storage device attached to the UE
Explanation: This is because, if the corresponding file for storing EPS security context parameters is absent on the USIM, these parameters (excluding the allowed CSG list) are stored in a non-volatile memory within the Mobile Equipment (ME), ensuring persistence across power cycles, and are accompanied by the IMSI retrieved from the USIM for association.