Radio station, radio terminal apparatus, and method for these

Abstract

A radio station ( 3 ) is configured to perform, with at least one radio terminal ( 1, 2 ), first radio communication in accordance with a first transmission time interval (TTI) and second radio communication in accordance with a second TTI. The first TTI is equal to a duration of one subframe ( 410, 510 ). The second TTI is shorter than the duration of the subframe ( 410, 510 ). The radio station ( 3 ) is configured to receive assistance information ( 802, 904 ) regarding the second radio communication from the radio terminal ( 2 ) capable of performing the second radio communication or from a higher network node ( 4 ).

1 . A radio station comprising:
 at least one transmitter; and   at least one processor, wherein   the at least one processor is configured to perform, with at least one radio terminal, radio communication in accordance with a time unit shorter than a duration of one subframe,   the at least one transmitter is configured to transmit, to the at least one radio terminal, configuration information including layer- 2  parameter for the radio communication, and   the configuration information includes information regarding on/off of hybrid automatic repeat request (HARQ) function on the at least one radio terminal.   
     
     
         2 . The radio station according  claim 1 , wherein the information regarding on/off of hybrid automatic repeat request (HARQ) function indicates on/off of HARQ for uplink transmission. 
     
     
         3 . The radio station according  claim 1 , wherein the information regarding on/off of hybrid automatic repeat request (HARQ) function indicates on/off of HARQ for downlink transmission. 
     
     
         4 . A radio terminal comprising:
 at least one transceiver configured to communicate with a radio station; and   at least one processor, wherein   the at least one processor is configured to perform radio communication in accordance with a time unit shorter than a duration of one subframe,   the at least one transceiver is configured to receive, from the radio station, configuration information including layer- 2  parameter for the radio communication, and   the configuration information includes information regarding on/off of hybrid automatic repeat request (HARQ) function on the radio terminal.   
     
     
         5 . The radio terminal according  claim 4 , wherein the information regarding on/off of hybrid automatic repeat request (HARQ) function indicates on/off of HARQ for uplink transmission. 
     
     
         6 . The radio station according  claim 4 , wherein the information regarding on/off of hybrid automatic repeat request (HARQ) function indicates on/off of HARQ for downlink transmission. 
     
     
         7 . A method for radio station comprising:
 performing, with at least one radio terminal, radio communication in accordance with a time unit shorter than a duration of one subframe; and   transmitting, to the at least one radio terminal, configuration information including layer-2 parameter for the radio communication, wherein   the configuration information includes information regarding on/off of hybrid automatic repeat request (HARQ) function on the at least one radio terminal.   
     
     
         8 . A method for radio terminal comprising:
 performing radio communication in accordance with a time unit shorter than a duration of one subframe; and   receiving, from the radio station, configuration information including layer-2 parameter for the radio communication, wherein   the configuration information includes information regarding on/off of hybrid automatic repeat request (HARQ) function on the radio terminal.