Communication device, communication control method and communication system

A communication device comprising:

• a first radio communication unit capable of radio communication, utilizing at least one antenna, in accordance with a first communication method;
• and
• a second radio communication unit capable of radio communication, utilizing at least one antenna, in accordance with a second communication method using millimeter waves and which is different than the first communication method,
• wherein
• the first radio communication unit transmits, in accordance with the first communication method, an instruction signal instructing to learn a beam directionality to another communication device,
• the second radio communication unit transmits, in accordance with the second communication method, a beam reference signal used for learning the beam directionality to said another communication device before completion of transmission of the instruction signal by the first radio communication unit,
• the millimeter waves used for radio communication by the second communication method are of higher frequency than frequencies used by the first communication method for radio communication,
• the instruction signal contains information that specifies a reception start time point which is a time at which the another communication unit is to begin receiving the beam reference signal in accordance with the second communication method, and
• the first radio communication unit and the second radio communication unit are each controlled by at least one processor.

A communication control method between a transmitting device and a receiving device, the transmitting device and the receiving device performing radio communication therebetween in accordance with a first communication method and performing radio communication therebetween in accordance with a second communication method which is different than the first communication method, the communication control method comprising the steps of:

• transmitting an instruction signal instructing to learn a beam directionality from the transmitting device to the receiving device in accordance with the first communication method;
• transmitting a beam reference signal used for learning the beam directionality from the transmitting device to the receiving device in accordance with the second communication method;
• starting reception, in accordance with the second communication method, of the beam reference signal from a certain reception start time point determined based on the received instruction signal that has been received by the receiving device in accordance with the first communication method;
• and
• determining a parameter for specifying a beam having an optimum directionality based on the received beam reference signal in the receiving device,
• wherein the second communication method uses millimeter waves for radio communication, and the millimeter waves used for radio communication by the second communication method are of higher in frequency than frequencies used by the first communication method for radio communication, and
• wherein the instruction signal contains information that specifies the certain reception start time point which is a time at which the receiving device is to begin receiving the beam reference signal.

A communication system comprising a transmitting device and a receiving device respectively including:

• a first radio communication unit capable of radio communication, utilizing at least one antenna, in accordance with a first communication method;
• and
• a second radio communication unit capable of radio communication, utilizing at least one antenna, in accordance with a second communication method using millimeter waves and which is different than the first communication method,
• wherein
• the first radio communication unit of the transmitting device transmits, in accordance with the first communication method, an instruction signal instructing to learn a beam directionality to the receiving device,
• the second radio communication unit of the transmitting device transmits, in accordance with the second communication method, a beam reference signal used for learning a beam directionality to the receiving device,
• the first radio communication unit of the second device is configured to, upon receiving the instruction signal in accordance with the first communication method, determine a reception start time point of the beam reference signal based on the instruction signal,
• the second radio communication unit of the receiving device starts reception, in accordance with the second communication method, of the beam reference signal from the determined reception start time point and determines a parameter value for specifying an optimum beam pattern based on the received beam reference signal,
• the millimeter waves used for radio communication by the second communication method are of higher frequency than frequencies used by the first communication method for radio communication,
• the instruction signal contains information that specifies the reception start time point which is a time at which the second radio communication unit of the receiving device is to begin receiving the beam reference signal, and
• the first radio communication unit and the second radio communication unit are each controlled by at least one processor.