A radio resource management system, comprising: a processing circuitry (10, 20, 30), configured to, acquire a range to be protected of at least one high priority system managed by the radio resource management system, the range to be protected being the range of locations where the at least one high priority system possibly appears and acquire a locating range of at least one low priority system managed by the radio resource management system, the locating range being the range of locations where the at least one low priority system possibly appears, based on location information of the at least one high priority system and location information of the at least one low priority system, and a locating error thereof, wherein, the high priority system has a higher priority than the low priority system with regard to the use of spectrum resource, and the low priority system opportunistically utilizes the spectrum resource; select, for each low priority system, with respect to each high priority system among the at least one high priority system, a location in the locating range of the low priority system in which the interference generated on the high priority system satisfies a predetermined condition, based on the range to be protected of the high priority system, as a reference location of the low priority system; and determine for each low priority system, with respect to each high priority system among the at least one high priority system, an operational parameter of the low priority system, with regard to the use of the spectrum of the high priority system based on the reference location of each low priority system. a processing circuitry (10, 20, 30), configured to, acquire a range to be protected of at least one high priority system managed by the radio resource management system, the range to be protected being the range of locations where the at least one high priority system possibly appears and acquire a locating range of at least one low priority system managed by the radio resource management system, the locating range being the range of locations where the at least one low priority system possibly appears, based on location information of the at least one high priority system and location information of the at least one low priority system, and a locating error thereof, wherein, the high priority system has a higher priority than the low priority system with regard to the use of spectrum resource, and the low priority system opportunistically utilizes the spectrum resource; select, for each low priority system, with respect to each high priority system among the at least one high priority system, a location in the locating range of the low priority system in which the interference generated on the high priority system satisfies a predetermined condition, based on the range to be protected of the high priority system, as a reference location of the low priority system; and determine for each low priority system, with respect to each high priority system among the at least one high priority system, an operational parameter of the low priority system, with regard to the use of the spectrum of the high priority system based on the reference location of each low priority system.