Terminal apparatus, base station apparatus, communication method, and integrated circuit

A base station apparatus that performs communication with a terminal apparatus supporting direct communication with another terminal apparatus, the base station apparatus comprising:

• a processor;
• and
• a memory, wherein
• the terminal apparatus performs direct communication with the another terminal apparatus and supports (i) a first radio resource allocation method, by which a radio resource to be used for the direct communication is scheduled by the base station apparatus, and (ii) a second 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, wherein
• the memory stores instructions that cause the processor to:
• configure information of a timer used to determine that the second radio resource allocation method, instead of the first radio resource allocation method, is to be used, and
• transmit the information, and
• the direct communication is performed with use of a specific radio resource allocation method,
• the specific radio resource allocation method is changed from the first radio resource allocation method into the second radio resource allocation method based on whether or not the timer is running, and
• the information indicates an integer value for the timer.

A communication method for use in a terminal apparatus capable of direct communication with another terminal apparatus, the terminal apparatus performs direct communication with the another terminal apparatus and supports (i) a first radio resource allocation method, by which a radio resource to be used for the direct communication is scheduled by a base station apparatus, and (ii) a second 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, wherein the communication method comprises at least:

• receiving information of a timer used to determine that the second radio resource allocation method, instead of the first radio resource allocation method, is to be used, and
• performing the direct communication with use of a specific radio resource allocation method,
• the specific radio resource allocation method is changed from the first radio resource allocation method into the second radio resource allocation method based on whether or not the timer is running, and
• the information indicates an integer value for the timer.

A communication method for use in a base station apparatus that performs communication with a terminal apparatus supporting direct communication with another terminal apparatus, the terminal apparatus performs direct communication with the another terminal apparatus and supports (i) a first radio resource allocation method, by which a radio resource to be used for the direct communication is scheduled by the base station apparatus, and (ii) a second 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, wherein the communication method comprises at least:

• configuring information of a timer used to determine that the second radio resource allocation method, instead of the first radio resource allocation method, is to be used, and
• transmitting the information, and
• the direct communication is performed with use of a specific radio resource allocation, the specific radio resource allocation method is changed from the first radio resource allocation method into the second radio resource allocation method based on whether or not the timer is running, and
• the information indicates an integer value for the timer.