Patent ID: 8811414

Claim:
A network system comprising a first network system and a second network system connected by a connecting node which belongs to both of said first and second network systems, each of said first and second network systems being a sub-network system in which a plurality of nodes and the connecting node are connected to one another to form a cascade or a loop and form a ring transmission route running through all of said plurality of nodes, wherein a frame including regions of a plurality of transmission channels is circulated along said ring transmission route, and each node transmits audio data and control data to other nodes in the sub-network system by writing the audio data and control data into the frame or receives audio data and control data from other nodes in the sub-network system by reading the audio data and control data from the frame, wherein: a first node in said first network system, other than said connecting node, works as a master node, which periodically generates and sends a first frame to said ring transmission route in said first network system, said connecting node periodically generates and sends a second frame to said ring transmission route in said second network system with a same period as receiving said first frame generated by said first node, a second node in said network system exclusively allocates, to said nodes in said network system, one or more transmission channels among the plurality of transmission channels, the allocation being commonly used in both of said first frame and said second frame, each node in said first network system and each node in said second network system respectively writes audio data to be sent to another node into each of the regions, in the frame received by the node, of the transmission channels allocated to the node, and said connecting node, based on the allocation of the transmission channel by said second node, a) reads audio data from respective regions, in said first frame, of the transmission channels allocated to any node in said first network system and writes the read audio data into the corresponding regions, in said second frame of the same transmission channels, and b) reads audio data from respective regions, in said second frame, of the transmission channels allocated to any node in said second network system and writes the read audio data into the corresponding regions, in said first frame, of the same transmission channels.