A system including multiple nodes performing radio communication, wherein each node stores routing information, uses it to determine a transmission path, and performs cut-through transmission by transmitting and receiving packets to and from a node on the determined path through transmission and reception radio waves given a directivity by controlling their phases. In the system, time synchronization and transmission and reception of packet communication records are performed during a certain time period by carrying out the cut-through transmission while controlling phases of the radio waves so that all of the nodes form one or more closed loops. The node transmits and receives packets in accordance with routing information and a time frame assigned to each of the nodes as a time when each node is allowed to transmit and receive a packet, updates the routing information, and shares it with each node.