A base station or a module for a base station comprising: a control unit configured to instruct a terminal device, which performs wireless communication of a cellular system, to transmit a first frame including duration information for setting a network allocation vector NAV using a frequency band shared between the wireless communication of the cellular system and wireless communication of a wireless local area network, WLAN, and perform wireless cellular communication with the terminal device using the shared frequency band in a period covered by the duration information after the transmission of said first frame, the period being a period which starts at a point in time at which a short inter-frame space SIFS has elapsed from an end time-point of the transmission of the first frame, characterized in that the control unit is further configured to control transmission by the terminal device of an additional frame at any time in said period including further duration information for setting a further NAV, and use another frequency band for the cellular system to instruct the terminal device to transmit the first frame using the shared frequency band. a control unit configured to instruct a terminal device, which performs wireless communication of a cellular system, to transmit a first frame including duration information for setting a network allocation vector NAV using a frequency band shared between the wireless communication of the cellular system and wireless communication of a wireless local area network, WLAN, and perform wireless cellular communication with the terminal device using the shared frequency band in a period covered by the duration information after the transmission of said first frame, the period being a period which starts at a point in time at which a short inter-frame space SIFS has elapsed from an end time-point of the transmission of the first frame, characterized in that instruct a terminal device, which performs wireless communication of a cellular system, to transmit a first frame including duration information for setting a network allocation vector NAV using a frequency band shared between the wireless communication of the cellular system and wireless communication of a wireless local area network, WLAN, and perform wireless cellular communication with the terminal device using the shared frequency band in a period covered by the duration information after the transmission of said first frame, the period being a period which starts at a point in time at which a short inter-frame space SIFS has elapsed from an end time-point of the transmission of the first frame, the control unit is further configured to control transmission by the terminal device of an additional frame at any time in said period including further duration information for setting a further NAV, and use another frequency band for the cellular system to instruct the terminal device to transmit the first frame using the shared frequency band. control transmission by the terminal device of an additional frame at any time in said period including further duration information for setting a further NAV, and use another frequency band for the cellular system to instruct the terminal device to transmit the first frame using the shared frequency band.