1. A communication system comprising a mobile terminal, a base station configured to perform
radio communication with the mobile terminal, and a radio network controller configured to
control the base station,
wherein the radio network controller is configured to notify the base station of a number of a subframe to be used as an MBSFN (Multimedia Broadcast multicast service Single Frequency Network) subframe,
the base station is configured to set, as a subframe for avoiding downlink interference, the MBSFN subframe having a number overlapping at least partially with the number of the subframe notified from the radio network controller,
the base station is configured to transmit, to the mobile terminal, the subframe for avoiding downlink interference, and
the mobile terminal is configured to receive the subframe for avoiding downlink interference.
2. The communication system as claimed in claim 1，
wherein the MBSFN subframe is a radio resource for transmitting a reference signal to the mobile terminal less frequently than normal, the reference signal being for measuring a power.
3. A base station used in a communication system comprising a mobile terminal, the base
station configured to perform radio communication with the mobile terminal, and a radio
network controller configured to control the base station,
wherein the base station is configured to be notified, from the radio network

controller, of a number of a subframe to be used as an MBSFN (Multimedia Broadcast multicast service Single Frequency Network) subframe,
the base station is configured to set, as a subframe for avoiding downlink interference, the MBSFN subframe having a number overlaps at least partially with the number of the subframe notified from the radio network controller, and
the base station is configured to transmit, to the mobile terminal, the subframe for avoiding downlink interference.
4. A mobile terminal used in a communication system comprising the mobile terminal, a base station configured to perform radio communication with the mobile terminal, and a radio network controller configured to control the base station,
wherein the mobile terminal is configured to receive a subframe for avoiding downlink interference, the subframe for avoiding downlink interference being set by the base station, the base station being configured to be notified, from the radio network controller, of a number of a subframe to be used as an MBSFN (Multimedia Broadcast multicast service Single Frequency Network) subframe, and
the subframe for avoiding downlink interference has a number overlapping at least partially with the number of the subframe to be used as the MBSFN subframe, the number of the subframe to be used as the MBSFN subframe being notified from the radio network controller.