Terminal apparatus for executing two-step random access procedure, base station apparatus, and control method

A base station apparatus including a communication unit,

• wherein the communication unit is controlled to
• receive predetermined messages from a plurality of terminal apparatuses based on a two-step random access procedure,
• transmit one signal including pieces of control information regarding upper layers for the respective terminal apparatuses in a multiplexed manner to the plurality of terminal apparatuses, in response to the predetermined messages,
• designate radio resources using which response signals indicating whether or not succeeded in receiving the control information are to be transmitted in response to the one signal and that are different between the plurality of terminal apparatuses, using at least one of a control signal used to transmit the one signal and the one signal, and
• receive the response signals from the plurality of terminal apparatuses, respectively, in the radio resources designated with respect to the respective terminal apparatuses.

A control method to be executed by a terminal apparatus, comprising:

• transmitting a predetermined message to a base station apparatus based on a two-step random access procedure,
• upon receiving one signal that is transmitted from the base station apparatus in response to the predetermined message, and includes pieces of upper layer control information for the terminal apparatus and another terminal apparatus in a multiplexed manner,
• specifying a first radio resource for transmitting a first response signal indicating whether or not succeeded in receiving control information that is for the terminal apparatus and is included in the one signal, and is different from a second radio resource for transmitting a second response signal indicating whether or not the other terminal apparatus has succeeded in receiving control information that is for the other terminal apparatus and is included in the one signal, based on at least one of a control signal that is used for transmitting the one signal and the one signal, and
• transmitting the first response signal using the first radio resource.

A control method that is to be executed by a base station apparatus, comprising:

• receiving predetermined messages from a plurality of terminal apparatuses based on a two-step random access procedure,
• transmitting one signal including pieces of upper layer control information for the respective terminal apparatuses in a multiplexed manner to the plurality of terminal apparatuses, in response to the predetermined messages,
• designating radio resources using which response signals indicating whether or not succeeded in receiving the control information are to be transmitted in response to the one signal and that are different between the plurality of terminal apparatuses, using at least one of a control signal used to transmit the one signal and the one signal, and
• receiving the response signals from the plurality of terminal apparatuses, respectively, in the radio resources designated with respect to the respective terminal apparatuses.