Method for transmitting data on resource selected by sensing or randomly selected in wireless communication system

A first terminal in a wireless communication system, comprising:

• at least one processor;
• and
• at least one computer memory operatively connected to the at least one processor and configured to store commands for allowing the at least one processor to perform operations when being executed,
• wherein the operations includes:
• switching to a resource allocation mode 2 from a resource allocation mode 1 based on a detection of a beam failure or a declaration of a radio link failure for a base station,
• wherein the resource allocation mode 1 is a mode that a transmission resource for a second terminal is determined by the base station, and the resource allocation mode 2 is a mode that the transmission resource for the second terminal is determined by the first terminal;
• and
• transmitting data to the second terminal on a resource selected in a resource pool for the resource allocation mode 2, and
• wherein, based on a first time period being equal to or larger than a second time period, the resource is selected by a sensing procedure for determining the resource is occupied by a second terminal,
• wherein, based on the first time period being smaller than the second time period, the resource is randomly selected, and
• wherein the first time period is a maximum limit period for transmitting the data and the second time period is an estimated period required for transmitting the data after the sensing procedure.

A hardware processor configured to perform operations of a first terminal in a wireless communication system, the operations comprising:

• switching to a resource allocation mode 2 from a resource allocation mode 1 based on a detection of a beam failure or a declaration of a radio link failure for a base station,
• wherein the resource allocation mode 1 is a mode that a transmission resource for a second terminal is determined by the base station, and the resource allocation mode 2 is a mode that the transmission resource for the second terminal is determined by the first terminal;
• and
• transmitting data to the second terminal on a resource selected in a resource pool for the resource allocation mode 2,
• wherein based on a first time period being equal to or larger than a second time period, the resource is selected by a sensing procedure for determining the resource is occupied by a second terminal,
• wherein, based on the first time period being smaller than the second time period, the resource is randomly selected, and
• wherein the first time period is a maximum limit period for transmitting the data and the second time period is an estimated period required for transmitting the data after the sensing procedure.

A non-transitory computer-readable recording medium having recorded thereon at least one program including a command for performing operations for a first terminal by at least one processor when being executed by the at least one processor, the operations comprising:

• switching to a resource allocation mode 2 from a resource allocation mode 1 based on a detection of a beam failure or a declaration of a radio link failure for a base station,
• wherein the resource allocation mode 1 is a mode that a transmission resource for a second terminal is determined by the base station, and the resource allocation mode 2 is a mode that the transmission resource for the second terminal is determined by the first terminal;
• and
• transmitting data to the second terminal on a resource selected in a resource pool for the resource allocation mode 2,
• wherein based on a first time period being equal to or larger than a second time period, the resource is selected by a sensing procedure for determining the resource is occupied by a second terminal,
• wherein, based on the first time period being smaller than the second time period, the resource is randomly selected, and
• wherein the first time period is a maximum limit period for transmitting the data and the second time period is an estimated period required for transmitting the data after the sensing procedure.