Coverage control method, base station apparatus, wireless communication system, and non-transitory computer readable medium having base station control program stored thereon

A base station apparatus in a wireless communication system that includes:

• a first cell;
• at least one second cell whose coverage at least partially overlaps the first cell;
• and at least one mobile station that is communicating in the first cell, wherein the base station apparatus that forms the first cell includes:
• hardware, including a processor and a memory;
• a load detecting unit that is implemented at least by the hardware and that detects that a load of the first cell is higher than a preset first load threshold;
• an accommodation candidate cell selecting unit that is implemented at least by the hardware and that selects an accommodation candidate cell from the at least one second cell based on a preset load condition, the selected accommodation candidate cell being a candidate to which the mobile station accommodated in the first cell is unloaded, and the preset load condition being related to a coverage target communication load that is a coverage control execution target;
• a continuously accommodated mobile station selecting unit that is implemented at least by the hardware and that selects a continuously accommodated mobile station from the at least one mobile station accommodated in the first cell based on radio quality of the selected accommodation candidate cell, the continuously accommodated mobile station continuing to be a coverage control target of the first cell;
• and
• a coverage controlling unit that is implemented at least by the hardware and that performs the coverage control of the first cell by targeting at the selected continuously accommodated mobile station,
• wherein the coverage target communication load is a total value of a load of the at least one mobile station satisfying a condition that the radio quality of the accommodation candidate cell is higher than a preset first quality threshold, the at least one mobile station being accommodated in the first cell, and
• wherein the accommodation candidate cell selecting unit selects as the accommodation candidate cell the at least one second cell taking the total value satisfying the load condition.

A non-transitory computer readable medium storing a base station control program that is executed by a computer in a base station apparatus that forms a first cell to control an operation of the base station apparatus in a wireless communication system that includes:

• the base station apparatus that forms the first cell;
• at least another base station apparatus that forms a second cell whose coverage partially overlaps the first cell;
• and at least one mobile station that is communicating in the first cell, wherein the operation includes:
• load detection processing of detecting that a load of the first cell is higher than a preset first load threshold;
• accommodation candidate cell selection processing of selecting an accommodation candidate cell from the second cell based on a preset load condition, the accommodation candidate cell being a candidate to which the mobile station accommodated in the first cell is unloaded, and the preset load condition being related to a coverage target communication load that is a coverage control execution target;
• continuously accommodated mobile station selection processing of selecting a continuously accommodated mobile station from the mobile station accommodated in the first cell based on radio quality of the selected accommodation candidate cell, the continuously accommodated mobile station continuing to be a coverage control target of the first cell;
• and
• coverage control processing of performing the coverage control of the first cell by targeting at the selected continuously accommodated mobile station,
• wherein the coverage target communication load is a total value of a load of the at least one mobile station satisfying a condition that the radio quality of the accommodation candidate cell is higher than a preset first quality threshold, the at least one mobile station being accommodated in the first cell, and
• wherein the accommodation candidate cell selection processing selects as the accommodation candidate cell the at least one second cell taking the total value satisfying the load condition.