Method for allocating and reserving resource for sidelink communication, and apparatus therefor

A sidelink (SL) communication method performed by a first terminal in a communication system, the SL communication method comprising:

• transmitting, to a second terminal, first sidelink control information (SCI) indicating a first transmission resource and one or more second transmission resources;
• transmitting a first redundancy version (RV) of a first transport block (TB) to the second terminal through the first transmission resource;
• and
• when a first configuration indicator is not set, transmitting a second RV of the first TB to the second terminal through a resource among the one or more second transmission resources;
• and when the first configuration indicator is set, transmitting the second RV of the first TB or a first RV of a second TB other than the first TB to the second terminal through a resource among the one or more second transmission resources,
• wherein configuration information including a list of candidate periodicities for the one or more second transmission resources is received from a base station, and when the first configuration indicator is set, the first SCI further includes an index indicating a reservation periodicity of the one or more second transmission resources among the list of candidate periodicities.