Radio communication apparatus, radio communication system and radio communication method

A radio communication apparatus used as a first radio communication apparatus in a radio communication system in which the first radio communication apparatus receives data from a plurality of second radio communication apparatus, the radio communication apparatus comprising:

• a control section which configures a first radio resource that can be used on a contention basis by the plurality of second radio communication apparatus for data transmission, and which selects making each second radio communication apparatus use the first radio resource or assigning to said each second radio communication apparatus a second radio resource used for transmitting a radio resource assignment request;
• and
• a notification section which selectively notifies said each second radio communication apparatus of information indicating permission to use the first radio resource or information indicating the assigned second radio resource according to a result of the selection by the control section,
• wherein when the information indicating permission to use the first radio resource is notified of, a transmission method using the first radio resource for data transmission is preferentially selected by said each second radio communication apparatus having received the information.

A radio communication system in which a first radio communication apparatus receives data from a plurality of second communication apparatuses, wherein

• the first communication apparatus configures a first radio resource which can be used on a contention basis by the plurality of second radio communication apparatus for data transmission;
• the plurality of radio communication apparatus performs a first transmission method using the first radio resource for data transmission and a second transmission method using a third radio resource that is assigned by the first radio communication apparatus through an assignment request using a second radio resource for a control channel assigned by the first radio communication apparatus for data transmission;
• and
• each of the plurality of second radio communication apparatus selectively performs one of the first transmission method and the second transmission method, and when receiving information indicating permission to use the first radio resource, preferentially selects the first transmission method.

A radio communication method in a radio communication system in which a first radio communication apparatus receives data from a plurality of second radio communication apparatus, the method comprising:

• configuring, by the first radio communication apparatus, a first radio resource that can be used on a contention basis by the plurality of second radio communication apparatus for data transmission;
• selectively performing, by each of at least a part of the plurality of second radio communication apparatus, one of a first transmission method using the first radio resource for data transmission and a second transmission method using a second radio resource for a control channel assigned by the first radio communication apparatus for assignment request transmission;
• preferentially selecting and performing, by said each second radio communication apparatus, the first transmission method when receiving information indicating permission to use the first radio resource;
• and
• assigning, by the first radio communication apparatus, a third radio resource for data transmission to a second radio communication apparatus which transmits an assignment request at the time of the second transmission method being performed.