A method, performed by a user equipment, UE, of performing sidelink communication, the UE being in idle or inactive state, the method comprising: obtaining a valid system information block, SIB, for a vehicle-to-everything, V2X, sidelink communication; autonomously determining a sidelink resource, based on information of a pool of sidelink resources included in the valid SIB for the V2X sidelink communication; and performing sidelink communication with another UE using the determined sidelink resource, wherein the obtaining the valid SIB for the V2X sidelink communication comprises: receiving, from a base station, a SIB including information for determining a validity of a stored SIB for the V2X sidelink communication, wherein the information for determining the validity of the stored SIB includes an area scope parameter, a system information area identification, ID, for a serving cell, and a value tag, and wherein the area scope parameter, system information area ID and the value tag are associated with a SIB for the V2X sidelink communication; determining the validity of the stored SIB for the V2X sidelink communication, based on the information for determining the validity of the stored SIB for the V2X sidelink communication, wherein the stored SIB is considered as the valid SIB in case that an area scope parameter of the stored SIB is the same as the area scope parameter of the received SIB, and that a first PLMN identity included in a PLMN identity information list, the system information area ID included in the received SIB, and the value tag included in the received SIB are identical to a PLMN identity, a system information area ID and a value tag that are associated with the stored SIB, respectively; and receiving, from the base station, the valid SIB for the V2X sidelink communication in case that the stored SIB for the V2X sidelink communication is determined to be invalid. obtaining a valid system information block, SIB, for a vehicle-to-everything, V2X, sidelink communication; autonomously determining a sidelink resource, based on information of a pool of sidelink resources included in the valid SIB for the V2X sidelink communication; and performing sidelink communication with another UE using the determined sidelink resource, wherein the obtaining the valid SIB for the V2X sidelink communication comprises: receiving, from a base station, a SIB including information for determining a validity of a stored SIB for the V2X sidelink communication, wherein the information for determining the validity of the stored SIB includes an area scope parameter, a system information area identification, ID, for a serving cell, and a value tag, and wherein the area scope parameter, system information area ID and the value tag are associated with a SIB for the V2X sidelink communication; determining the validity of the stored SIB for the V2X sidelink communication, based on the information for determining the validity of the stored SIB for the V2X sidelink communication, wherein the stored SIB is considered as the valid SIB in case that an area scope parameter of the stored SIB is the same as the area scope parameter of the received SIB, and that a first PLMN identity included in a PLMN identity information list, the system information area ID included in the received SIB, and the value tag included in the received SIB are identical to a PLMN identity, a system information area ID and a value tag that are associated with the stored SIB, respectively; and receiving, from the base station, the valid SIB for the V2X sidelink communication in case that the stored SIB for the V2X sidelink communication is determined to be invalid. receiving, from a base station, a SIB including information for determining a validity of a stored SIB for the V2X sidelink communication, wherein the information for determining the validity of the stored SIB includes an area scope parameter, a system information area identification, ID, for a serving cell, and a value tag, and wherein the area scope parameter, system information area ID and the value tag are associated with a SIB for the V2X sidelink communication; determining the validity of the stored SIB for the V2X sidelink communication, based on the information for determining the validity of the stored SIB for the V2X sidelink communication, wherein the stored SIB is considered as the valid SIB in case that an area scope parameter of the stored SIB is the same as the area scope parameter of the received SIB, and that a first PLMN identity included in a PLMN identity information list, the system information area ID included in the received SIB, and the value tag included in the received SIB are identical to a PLMN identity, a system information area ID and a value tag that are associated with the stored SIB, respectively; and receiving, from the base station, the valid SIB for the V2X sidelink communication in case that the stored SIB for the V2X sidelink communication is determined to be invalid.