Wireless communication system having relay device, and method for selecting relay terminal

In wireless communication systems into which a relay device has been introduced, although terminal reception quality increases, data transmission by relay devices with low contribution causes interference in other data transmission, which invites a decrease in reception quality of electromagnetic waves received by terminals. As a way to resolve the abovementioned issue, as one embodiment of the present disclosures, a wireless relay station is configured so as to receive a plurality of data addressed for wireless terminals from a wireless base station, and to transmit data that are selected from the aforementioned received plurality of data and that are addressed to the aforementioned wireless terminals which are the destinations of transmission. As a result, interference towards other data transmission and reception caused by data transmission of a relay device can be suppressed, and the reception quality of electromagnetic waves received by the terminal can be increased.