Methods and apparatuses for a DAPS failure recovery mechanism and a MRO mechanism for CHO and DAPS procedures
Embodiments of the present application relate to methods and apparatuses for a dual active protocol stack (DAPS) failure recovery mechanism and a mobility robustness optimization (MRO) mechanism for conditional handover (CHO) and DAPS procedures. According to an embodiment of the present application, a method can include: receiving CHO configuration information, wherein the CHO configuration information is associated with a CHO candidate cell, wherein the CHO configuration information includes a RRC reconfiguration message and a set of one or more execution conditions; in response to meeting one or more execution conditions associated with the CHO candidate cell, performing a CHO procedure from a source cell to the CHO candidate cell; and in response to successfully accessing the CHO candidate cell or in response to an occurrence of a failure during the CHO procedure, transmitting time related assistant information to a serving cell, wherein the serving cell is one of the source cell and the CHO candidate cell. In addition, a recovery procedure and a MRO mechanism associated with a DAPS handover procedure are also studied.
1 . A method performed by a user equipment (UE), the method comprising:
receiving first conditional handover (CHO) configuration information that is associated with a CHO candidate cell, the first CHO configuration information including a first radio resource control (RRC) reconfiguration message and a first set of one or more execution conditions;
in response to meeting one or more execution conditions associated with the CHO candidate cell, performing a CHO procedure from a source cell to the CHO candidate cell; and
in response to successfully accessing the CHO candidate cell or in response to an occurrence of a failure during the CHO procedure, transmitting time related assistant information to a serving cell that is one of the source cell or the CHO candidate cell, wherein the time related assistant information includes a time duration between a time instance of receiving a latest CHO configuration information and a time instance of starting to perform the CHO procedure.
2 . The method of claim 1 , further comprising:
in response to successfully completing the CHO procedure, transmitting, to the CHO candidate cell, an indication of an available state of the time related assistant information;
receiving, from the CHO candidate cell, a UE information request message after successfully completing the CHO procedure; and
transmitting a UE information response message to the CHO candidate cell, wherein the UE information response message includes the time related assistant information.
3 . The method of claim 1 , further comprising:
receiving the latest CHO configuration information before performing the CHO procedure, wherein the latest CHO configuration information is associated with the CHO candidate cell and includes one of:
a latest RRC reconfiguration message and the first set of one or more execution conditions;
the first RRC reconfiguration message and a latest set of one or more execution conditions associated with the CHO candidate cell; or
the latest RRC reconfiguration message and the latest set of one or more execution conditions.
4 . The method of claim 1 , further comprising:
storing at least one of:
a time instance of receiving the first CHO configuration information;
a time instance of receiving a latest RRC reconfiguration message;
a time instance of receiving a latest set of one or more execution conditions;
the time instance of receiving the latest CHO configuration information; or
the time instance of starting to perform the CHO procedure.
5 . A user equipment (UE) 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 UE to:
receive first conditional handover (CHO) configuration information that is associated with a CHO candidate cell, the first CHO configuration information including a first radio resource control (RRC) reconfiguration message and a first set of one or more execution conditions;
in response to meeting one or more execution conditions associated with the CHO candidate cell, perform a CHO procedure from a source cell to the CHO candidate cell; and
in response to successfully accessing the CHO candidate cell or in response to an occurrence of a failure during the CHO procedure, transmit time related assistant information to a serving cell that is one of the source cell or the CHO candidate cell, wherein the time related assistant information includes a time duration between a time instance of receiving a latest CHO configuration information and a time instance of starting to perform the CHO procedure.
6 . The UE of claim 5 , wherein the at least one processor is configured to cause the UE to:
in response to successfully completing the CHO procedure, transmit, to the CHO candidate cell, an indication of an available state of the time related assistant information;
receive, from the CHO candidate cell, a UE information request message after successfully completing the CHO procedure; and
transmit a UE information response message to the CHO candidate cell, wherein the UE information response message includes the time related assistant information.
7 . The UE of claim 5 , wherein the at least one processor is configured to cause the UE to receive the latest CHO configuration information before performing the CHO procedure, wherein the latest CHO configuration information is associated with the CHO candidate cell and includes one of:
a latest RRC reconfiguration message and the first set of one or more execution conditions;
the first RRC reconfiguration message and a latest set of one or more execution conditions associated with the CHO candidate cell; or
the latest RRC reconfiguration message and the latest set of one or more execution conditions.
8 . The UE of claim 5 , wherein the at least one processor is configured to cause the UE to store at least one of:
a time instance of receiving the first CHO configuration information;
a time instance of receiving a latest RRC reconfiguration message;
a time instance of receiving a latest set of one or more execution conditions;
the time instance of receiving the latest CHO configuration information; or
the time instance of starting to perform the CHO procedure.
9 . The UE of claim 5 , wherein the at least one processor is configured to cause the UE to:
receive a dual active protocol stack (DAPS) handover command;
perform a DAPS handover procedure from the source cell to a target cell, the DAPS handover procedure including to:
start a handover timer;
perform a random access (RA) procedure to the target cell; and
in response to failing to complete the DAPS handover procedure or in response to successfully completing a DAPS recovery procedure, transmit assistant information to the serving cell that is one of the source cell or the target cell.
10 . A user equipment (UE) 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 UE to:
receive first conditional handover (CHO) configuration information that is associated with a CHO candidate cell, the first CHO configuration information including a first radio resource control (RRC) reconfiguration message and a first set of one or more execution conditions;
in response to meeting one or more execution conditions associated with the CHO candidate cell, perform a CHO procedure from a source cell to the CHO candidate cell;
in response to successfully accessing the CHO candidate cell or in response to an occurrence of a failure during the CHO procedure, transmit time related assistant information to a serving cell that is one of the source cell or the CHO candidate cell, wherein the time related assistant information includes a time duration between a time instance of receiving a latest CHO configuration information and a time instance of starting to perform the CHO procedure;
in response to successfully completing the CHO procedure, transmit, to the CHO candidate cell, an indication of an available state of the time related assistant information;
receive, from the CHO candidate cell, a UE information request message after successfully completing the CHO procedure; and
transmit a UE information response message to the CHO candidate cell, wherein the UE information response message includes the time related assistant information.
11 . The UE of claim 10 , wherein the at least one processor is further configured to cause the UE to:
receive the latest CHO configuration information before performing the CHO procedure, wherein the latest CHO configuration information is associated with the CHO candidate cell and includes one of:
a latest RRC reconfiguration message and the first set of one or more execution conditions;
the first RRC reconfiguration message and a latest set of one or more execution conditions associated with the CHO candidate cell; or
the latest RRC reconfiguration message and the latest set of one or more execution conditions.
12 . The UE of claim 10 , wherein the at least one processor is further configured to cause the UE to:
store at least one of:
the time instance of receiving the first CHO configuration information;
the time instance of receiving a latest RRC reconfiguration message;
the time instance of receiving a latest set of one or more execution conditions;
the time instance of receiving the latest CHO configuration information; or
the time instance of starting to perform the CHO procedure.