Patent ID: 8103369

Claim:
A network system configured such that a plurality of nodes each comprising receivers and transmitters are connected in series by communication cables to form a loop transmission route for periodically circulating along said route an audio transport frame in a single direction, said audio transport frame generated by a master node in said plurality of nodes, said audio transport frame comprising a plurality of storage regions for audio signals, wherein each of said nodes other than said master node comprises: a reader that reads out, when said receiver receives the audio transport frame, audio signals from a predetermined storage region of the audio transport frame, and/or a writer that writes audio signals into a predetermined storage region of the audio transport frame received by said receiver; and a transmission controller that supplies the audio transport frame from/to which reading-out by said reader and/or writing by said writer have been performed to said transmitter, and controls said transmitter to transmit the audio transport frame after a lapse of a predetermined time from a timing at which said receiver receives the audio transport frame, and wherein said master node comprises: a buffer that stores the audio transport frame received by said receiver; a wordclock generator that generates a wordclock at a constant period; a judging device that judges whether the audio transport frame received by said receiver has circulated normally along the loop transmission route or not, wherein the audio transport frame is judged to not have circulated normally along the loop transmission route if there is an error in the audio transport frame; an audio transport frame generator that generates the audio transport frame in an (S+k)-th period later than an S-th period by k periods (where k is an integer greater than or equal to 2), based on the audio transport frame in the S-th period when said judging device judges that the audio transport frame in the S-th period of the audio transport frames stored in said buffer has circulated normally, or based on a predetermined model when said judging device judges that the audio transport frame in the S-th period has not circulated normally; a reader that reads out, when said receiver receives an audio transport frame in the S-th period, audio signals from a predetermined storage region of the audio transport frame in the S-th period or an audio transport frame in the (S+k)-th period generated by said audio transport frame generator based on the received transport frame, and/or a writer that writes audio signals into a predetermined storage region of either of the audio transport frames; and a transmission controller that supplies the audio transport frame in the (S+k)-th period generated by said audio transport frame generator to said transmitter, and controls said transmitter to transmit the audio transport frame in synchronization with the wordclock in the (S+k)-th period.