A communication system configured to operate in time division duplex, TDD, for which a first time period and a second time period different from the first time period are set in each of predetermined time intervals, the predetermined time intervals being subframes, the communication system comprising: a base station; a first terminal configured to execute radio transmission of data between the first terminal and the base station in either one of an uplink and a downlink during a first time period and radio transmission of a response signal to the data between the first terminal and the base station in the other one of the uplink and the downlink in a direction opposite to the first time period during a second time period after the first time period in each of the predetermined time intervals; and a second terminal that is different from the first terminal and is configured to: execute radio transmission between the second terminal and the base station in a link in the same direction as the first terminal during a first time period in each of the predetermined time intervals; and not execute radio transmission between the second terminal and the base station during the second time period, wherein the base station is configured to allocate radio resources for the first and second terminals (121, 122), the radio resources including subcarrier spacings and transmission time intervals, wherein the first terminal is configured to execute said radio transmission between the first terminal and the base station by using a first frequency band, and wherein the second terminal is configured to execute said radio transmission between the second terminal and the base station by using a second frequency band different from the first frequency band. a base station; a first terminal configured to execute radio transmission of data between the first terminal and the base station in either one of an uplink and a downlink during a first time period and radio transmission of a response signal to the data between the first terminal and the base station in the other one of the uplink and the downlink in a direction opposite to the first time period during a second time period after the first time period in each of the predetermined time intervals; and a second terminal that is different from the first terminal and is configured to: execute radio transmission between the second terminal and the base station in a link in the same direction as the first terminal during a first time period in each of the predetermined time intervals; and not execute radio transmission between the second terminal and the base station during the second time period, execute radio transmission between the second terminal and the base station in a link in the same direction as the first terminal during a first time period in each of the predetermined time intervals; and not execute radio transmission between the second terminal and the base station during the second time period, wherein the base station is configured to allocate radio resources for the first and second terminals (121, 122), the radio resources including subcarrier spacings and transmission time intervals, wherein the first terminal is configured to execute said radio transmission between the first terminal and the base station by using a first frequency band, and wherein the second terminal is configured to execute said radio transmission between the second terminal and the base station by using a second frequency band different from the first frequency band.