This page summarizes the required modem features for supporting an eSIM chip or removable eSIM 4FF card.
These are the modem requirements for general eSIM support. The Local Profile Assistant (LPA) needs the modem to support all of these requirements to function properly.
Handle the default boot profile correctly
When there is no operational or test profile enabled on eSIM, the default boot profile is enabled. The modem shall recognize the eSIM with the default boot profile enabled as a valid SIM, shall report the card as valid to upper layers, and shall not turn off the SIM power.
Send terminal capabilities correctly
On power-up, the modem shall send correct terminal capabilities to the eSIM. The terminal capability shall encode support for eUICC capabilities: "Local Profile Management" and "Profile Download".
See ETSI TS 102 221 Section 184.108.40.206.4: “Additional Terminal capability indications related to eUICC". Bytes [1-3] shall be: ‘83 (Tag) ‘01’ (Length) ‘07’ (eUICC capabilities).
(Optional) Support eSIM OS OTA updates
The modem shall support all requirements for eSIM OS OTA updates, for example switching to passthrough mode and keeping the eSIM powered on during the OTA update procedure.
These are API implementations that are required for general eSIM support.
Implement setSimPower API in Radio HAL v1.1
The modem shall support the setSimPower API.
Implement getSimSlotsStatus API in IRadioConfig HAL v1.0
The modem shall support the getSimSlotsStatus API, which indicates whether a slot contains an eSIM.
Implement getIccCardStatus API in IRadio HAL v1.2
The modem shall provide the Answer To Reset (ATR) and slot ID of the card status in the getIccCardStatusResponse API. This API was introduced in v1.0 and, in v1.2, CardStatus was changed to include ATR.
Set CardState:RESTRICTED on SIM lock (subsidy lock)
(Optional) Implement setSimSlotsMapping API in IRadioConfig HAL v1.0
The modem shall support the setSimSlotsMapping API, which sets the mapping from physical slots to logical slots. The LPA uses this API to select the active SIM slot.
These are general modem logging requirements for debugging eSIM issues.
Logging shall capture inter-processor communication, SIM functionality, Radio Interface Layer (RIL) logging, and application protocol data unit (APDU) logging.
Device software shall support an on-device modem log capturing mechanism.
Log config support
Device software shall support different modem logging configurations (level, modules). These configurations shall be supported for both on-device logging and PC-tool-based logging.
Android bug report
Bug reports shall contain modem logs, vendor RIL logs, panic signature logs, and Android logs.