Methods and apparatuses for a mobility robustness optimization (mro) mechanism of an inter-rat handover procedure

An apparatus for wireless communication, comprising:

• at least one memory;
• and
• at least one processor coupled with the at least one memory and configured to cause the apparatus to:
• transmit a mobility command message to a user equipment (UE),
• wherein the mobility command message includes an identifier (ID) of a target cell of the UE, and
• wherein the target cell is at least one of an evolved universal terrestrial radio access network (E-UTRAN) cell and a universal terrestrial radio access network (UTRAN) cell;
• and
• receive radio link failure (RLF) report information.

A method performed by an apparatus for wireless communication, the method comprising:

• receiving a radio resource control (RRC) release message from a source new radio (NR) cell,
• wherein the RRC release message includes a voice fallback indication, and
• wherein the voice fallback indication indicates that the RRC release message is triggered by a voice fallback operation;
• entering into a RRC idle state;
• performing a cell selection procedure;
• in response to failing to setup a connection with an evolved universal terrestrial radio access network (E-UTRAN) cell after selecting the E-UTRAN cell or in response to failing to select an E-UTRAN cell, selecting an NR cell;
• and
• transmitting radio link failure (RLF) report information to a serving cell.

A method performed by an apparatus for wireless communication, the method comprising:

• transmitting a mobility command message to a user equipment (UE),
• wherein the mobility command message includes an identifier (ID) of a target cell of the UE, and
• wherein the target cell is at least one of an evolved universal terrestrial radio access network (E-UTRAN) cell and a universal terrestrial radio access network (UTRAN) cell;
• and
• receiving radio link failure (RLF) report information.