Path loss calculation method, path loss calculation device, path loss calculation program, wireless communication system, and spectrum manager

A wireless communication system in which a secondary system shares the same frequency as a frequency of a transmitting station of a primary system, and permissible power of a transmission signal of the secondary system is controlled so that the transmission signal of the secondary system does not cause the primary system to undergo interference, the wireless communication system comprising:

• the primary system including at least a transmitting station of the primary system and a receiving station of the primary system;
• and
• the secondary system including a transmitting station of the secondary system, a spectrum manager that manages a transmission signal received from the transmitting station of the secondary system, and a monitoring station that is arranged in or around a service area of the transmitting station of the primary system and measures reception power of the transmission signal received from the transmitting station of the secondary system,
• wherein the spectrum manager estimates a path loss value between the transmitting station of the secondary system and the receiving station of the primary system at a first frequency, corrects the estimated path loss value between the transmitting station of the secondary system and the receiving station of the primary system using one of a reception power value of a radio signal of the transmitting station of the secondary system which is transmitted at a second frequency of the transmitting station of the primary system different from the first frequency and a reception power value of the transmission signal received from the transmitting station of the secondary system which is transmitted in a period of time in which the transmitting station of the primary system does not use the first frequency, and calculates permissible transmission power of the transmitting station of the secondary system using the corrected path loss value.

A spectrum manager that manages a secondary system that shares the same frequency as a frequency of a transmitting station of a primary system, comprising:

• a communication unit that receives a reception power value measured by a monitoring station positioned in or around a service area of the transmitting station of the primary system;
• a path loss estimating unit that estimates a path loss value between the transmitting station of the secondary system and the receiving station of the primary system at a first frequency;
• a measurement result storage unit that holds the reception power value measured by the monitoring station;
• a path loss correcting unit that corrects the estimated path loss value between the transmitting station of the secondary system and the receiving station of the primary system using one of a reception power value of a radio signal of the transmitting station of the secondary system which is transmitted at a second frequency of the transmitting station of the primary system different from the first frequency and a reception power value of a radio signal of the transmitting station of the secondary system which is transmitted in a period of time in which the transmitting station of the primary system does not use the first frequency;
• and
• a permissible power setting unit that calculates permissible transmission power of the transmitting station of the secondary system using the corrected path loss value.