A non-anchor radio base station (310B) comprises an interface (315B) that notifies the anchor radio base station (310A) of a delay profile between the non-anchor radio base station (310B) and the UE (10). An anchor radio base station (310A) comprises an interface (315A) that notifies a non-anchor radio base station (310B), notifying the delay profile which does not satisfy a predetermined condition, of stoppage of a process of transmitting an uplink signal before decoding through a backhaul network. The non-anchor radio base station (310B) comprises an interface (315B) that stops the process of transmitting the uplink signal before decoding when the non-anchor radio base station (310B) is notified of the stoppage of the process of transmitting the uplink signal before decoding.