Wireless communication system, wireless communication method, cooperation control apparatus, terminal apparatus, and licensed band base station apparatus

A wireless communication method in a wireless communication system including a plurality of terminal apparatuses that perform wireless communication using a first frequency band in which wireless communication based on a random access scheme is performed and a second frequency band which is different from the first frequency band, a first base station apparatus that performs wireless communication with the terminal apparatuses using the first frequency band, a second base station apparatus that performs wireless communication with the terminal apparatuses using the second frequency band, and a cooperation control apparatus that selects a terminal apparatus that transmits user data via the first base station apparatus from among the plurality of terminal apparatuses based on one or both of first communication quality in the wireless communication which is performed between the first base station apparatus and the terminal apparatuses and second communication quality in the wireless communication which is performed between the second base station apparatus and the terminal apparatuses, the wireless communication method comprising:

• a first step of causing the cooperation control apparatus to select which of the first base station apparatus and the selected terminal apparatus acquires access right for transmission of the user data;
• a second step of causing the cooperation control apparatus to generate an unlicensed channel (UC) communication initiation signal indicating a determined access right acquiring apparatus and to output the generated UC communication initiation signal to the first base station apparatus and the second base station apparatus;
• and
• a third step of causing the second base station apparatus to transmit the UC communication initiation signal input from the cooperation control apparatus to the selected terminal apparatus, wherein the selected terminal apparatus, based on the UC communication initiation signal received from the second base station apparatus,
• transmits the user data or the UC transmission request signal for causing the first base station apparatus to perform transmission to the first base station apparatus if the selected terminal apparatus is designated as the access right acquiring apparatus, and
• waits until the user data or the UC transmission request signal is received without performing transmission to the first base station if the selected terminal apparatus is not designated as the access right acquiring apparatus;
• and
• a fourth step of causing the first base station apparatus or the selected terminal apparatus notified as the access right acquiring apparatus to acquire access right in the first frequency band and to transmit the user data via the first base station apparatus using the first frequency band when the UC communication initiation signal is received from the cooperation control apparatus,
• a fifth step of causing the first base station apparatus to
• waits until the user data or a UC transmission request signal is received without performing transmission to the selected terminal apparatus if the selected terminal apparatus is designated as the access right acquiring apparatus, and
• perform transmission of the user data to the selected terminal apparatus or transmission of the UC transmission request signal for causing the selected terminal apparatus to perform transmission using the first frequency band to the selected terminal apparatus based on information provided by the UC communication initiation signal if the selected terminal apparatus is not designated as the access right acquiring apparatus,
• wherein the cooperation control apparatus controls acquisition of the access right in the first frequency band using communication in the second frequency band.

A cooperation control apparatus in a wireless communication system including a plurality of terminal apparatuses that perform wireless communication using a first frequency band in which wireless communication based on a random access scheme is performed and a second frequency band which is different from the first frequency band, a first base station apparatus that performs wireless communication with the terminal apparatuses using the first frequency band, a second base station apparatus that performs wireless communication with the terminal apparatuses using the second frequency band, and the cooperation control apparatus that controls transmission of user data of the terminal apparatuses, the cooperation control apparatus comprising:

• a path evaluating unit that selects a terminal apparatus that transmits the user data via the first base station apparatus from among the plurality of terminal apparatuses based on one or both of first communication quality in the wireless communication which is performed between the first base station apparatus and the terminal apparatuses and second communication quality in the wireless communication which is performed between the second base station apparatus and the terminal apparatuses, selects which of the first base station apparatus and the selected terminal apparatus acquires access right for transmission of the user data, and outputs a communication condition in the first frequency band including at least designation of an access right acquiring apparatus to the first base station apparatus and the second base station apparatus,
• wherein the first base station apparatus
• waits until the user data or a UC transmission request signal is received without performing transmission to the selected terminal apparatus if the selected terminal apparatus is designated as the access right acquiring apparatus, and
• performs transmission of the user data to the selected terminal apparatus or transmission of the UC transmission request signal for causing the selected terminal apparatus to perform transmission using the first frequency band to the selected terminal apparatus based on information provided by the UC communication initiation signal if the selected terminal apparatus is not designated as the access right acquiring apparatus, wherein the selected terminal apparatus, based on the UC communication initiation signal received from the second base station apparatus,
• transmits the user data or the UC transmission request signal for causing the first base station apparatus to perform transmission to the first base station apparatus if the selected terminal apparatus is designated as the access right acquiring apparatus, and
• waits until the user data or the UC transmission request signal is received without performing transmission to the first base station if the selected terminal apparatus is not designated as the access right acquiring apparatus,
• wherein the cooperation control apparatus controls acquisition of the access right in the first frequency band using communication in the second frequency band.

A terminal apparatus selected in a wireless communication system including a plurality of terminal apparatuses that perform wireless communication using a first frequency band in which wireless communication based on a random access scheme is performed and a second frequency band which is different from the first frequency band, a first base station apparatus that performs wireless communication with the terminal apparatuses using the first frequency band, a second base station apparatus that performs wireless communication with the terminal apparatuses using the second frequency band, and a cooperation control apparatus that selects the terminal apparatus that transmits user data via the first base station apparatus from among the plurality of terminal apparatuses based on one or both of first communication quality in the wireless communication which is performed between the first base station apparatus and the terminal apparatuses and second communication quality in the wireless communication which is performed between the second base station apparatus and the terminal apparatuses, the terminal apparatus comprising:

• a receiving unit that receives an unlicensed channel (UC) communication initiation signal including designation of an access right acquiring apparatus which is determined by the cooperation control apparatus from the second base station apparatus;
• and
• a transmitting unit that, based on the UC communication initiation signal received from the second base station apparatus, transmits the user data or a UC transmission request signal for causing the first base station apparatus to perform transmission to the first base station apparatus if the selected terminal apparatus is designated as the access right acquiring apparatus by the UC communication initiation signal, and waits until the user data or the UC transmission request signal is received without performing transmission to the first base station if the selected terminal apparatus is not designated as the access right acquiring apparatus, and
• wherein acquisition of the access right in the first frequency band is controlled using communication in the second frequency band.

A licensed band base station apparatus in a wireless communication system including a plurality of terminal apparatuses that perform wireless communication using a first frequency band in which wireless communication based on a random access scheme is performed and a second frequency band which is different from the first frequency band, a first base station apparatus that performs wireless communication with the terminal apparatuses using the first frequency band, and a cooperation control apparatus that controls transmission of user data of the terminal apparatuses, the licensed band base station apparatus comprising:

• a communication unit that performs wireless communication with the terminal apparatuses using the second frequency band;
• a collection unit that collects information on the terminal apparatuses via the communication unit;
• and
• a generation unit that generates an unlicensed channel (UC) communication initiation signal indicating a communication condition in the first frequency band including at least designation of an access right acquiring apparatus,
• wherein in a case of transmission of the user data in a downlink to the terminal apparatuses, when information on a terminal apparatus selected to transmit the user data via the first base station apparatus from among the plurality of terminal apparatuses is received from the cooperation control apparatus, the information on the selected terminal apparatus is collected by the collection unit and the UC communication initiation signal is generated by the generation unit based on the collected information,
• in a case of transmission of the user data in uplinks from the terminal apparatuses, when the information on the terminal apparatuses collected by the collection unit is provided to the cooperation control apparatus and information on a terminal apparatus selected to transmit the user data via the first base station apparatus from among the plurality of terminal apparatuses is received from the cooperation control apparatus, the UC communication initiation signal is generated by the generation unit based on the received information,
• the generated UC communication initiation signal is transmitted to the selected terminal apparatus via the communication unit, and
• acquisition of access right in the first frequency band is controlled using communication in the second frequency band,
• wherein the selected terminal apparatus, based on the UC communication initiation signal received from the licensed band base station apparatus,
• transmits the user data or the UC transmission request signal for causing the first base station apparatus to perform transmission to the first base station apparatus if the selected terminal apparatus is designated as the access right acquiring apparatus, and
• waits until the user data or the UC transmission request signal is received without performing transmission to the first base station if the selected terminal apparatus is not designated as the access right acquiring apparatus.