A terminal apparatus capable of direct communication with another terminal apparatus, and supporting a first radio resource allocation method and a second radio resource allocation method, wherein the first radio resource allocation method is a radio resource allocation method, by which a radio resource to be used for the direct communication is scheduled by a base station apparatus, and the second radio resource allocation method is a radio resource allocation method, by which the terminal apparatus autonomously selects a radio resource to be used for the direct communication from allocated radio resources, the terminal apparatus comprising a CPU executing a program that causes the terminal apparatus to: receive information of a timer used to determine that a specific radio resource allocation method is to be temporarily changed from the first radio resource allocation method to the second radio resource allocation method, receive a system information block which is SIB 18 indicating that the second radio resource allocation method is permitted, and indicating resource pool information for scheduling assignments related to the direct communication and resource pool information for transmission data related to the direct communication, change, based on the timer and the system information block, the specific radio resource allocation method from the first radio resource allocation method to the second radio resource allocation method, temporarily, perform the direct communication with use of a radio resource, which radio resource is allocated with use of the second radio resource allocation method to which the specific radio resource allocation method is temporarily changed, and receive from the base station apparatus a notification of the radio resource allocated with use of the second radio resource allocation method to which the specific radio resource allocation method is temporarily changed to, wherein this notified radio resource is independent of the radio resource indicated by system information. receive information of a timer used to determine that a specific radio resource allocation method is to be temporarily changed from the first radio resource allocation method to the second radio resource allocation method, receive a system information block which is SIB 18 indicating that the second radio resource allocation method is permitted, and indicating resource pool information for scheduling assignments related to the direct communication and resource pool information for transmission data related to the direct communication, change, based on the timer and the system information block, the specific radio resource allocation method from the first radio resource allocation method to the second radio resource allocation method, temporarily, perform the direct communication with use of a radio resource, which radio resource is allocated with use of the second radio resource allocation method to which the specific radio resource allocation method is temporarily changed, and receive from the base station apparatus a notification of the radio resource allocated with use of the second radio resource allocation method to which the specific radio resource allocation method is temporarily changed to, wherein this notified radio resource is independent of the radio resource indicated by system information.