A transmission area is specified flexibly in accordance with the contents of a flow. An area identification number (SHOG) is specified for each interlaced stream of wireless base stations. The same flow is sent at the same timing (or substantially at the same timing) in the interlaced stream specified for the same SHOG. A wireless terminal determines a neighbor sector or a neighbor wireless base station sending the same flow, in accordance with information given from the wireless base stations, and receives and combines the flows.