Beam failure recovery for serving cell

A method, comprising:

• receiving, from a terminal device, a medium access control control element, the medium access control control element comprising a field associated with a serving cell of the terminal device, the serving cell comprising at least one of a primary cell or a secondary cell serving the terminal device, wherein the field is set to be a predefined value indicating a beam failure;
• and
• determining, based on the field in the medium access control control element, the beam failure on the serving cells,
• wherein the serving cell comprises the secondary cell and the field associated with the serving cell is included in a bitmap, the bitmap including a plurality of fields, each of the plurality of fields associated with a secondary cell or a group of secondary cells.

A terminal device comprising:

• at least one processor;
• and
• at least one non-transitory memory storing instructions, that when executed by the at least one processor, cause the terminal device at least to:
• detect a beam failure on a serving cell of a terminal device, the serving cell comprising at least one of a primary cell or a secondary cell serving the terminal device;
• and
• in response to detecting the beam failure on the serving cell, generate a medium access control control element, the medium access control control element comprising a field associated with the serving cell,
• wherein the field is set to be a predefined value indicating the beam failure;
• and transmitting the medium access control control element to a network device associated with the serving cell, and
• wherein the serving cell comprises the secondary cell and the field associated with the serving cell is included in a bitmap, the bitmap including a plurality of fields, each of the plurality of fields associated with a secondary cell or a group of secondary cells.

A network device comprising:

• at least one processor;
• and
• at least one non-transitory memory storing instructions, that when executed by the at least one processor, cause the terminal device at least to:
• receive, from a terminal device, a medium access control control element, the medium access control control element comprising a field associated with a serving cell of the terminal device, the serving cell comprising at least one of a primary cell or a secondary cell serving the terminal device, wherein the field is set to be a predefined value indicating a beam failure;
• and
• determine, based on the field in the medium access control control element, the beam failure on the serving cell,
• wherein the serving cell comprises the secondary cell and the field associated with the serving cell is included in a bitmap, the bitmap including a plurality of fields, each of the plurality of fields associated with a secondary cell or a group of secondary cells.