Audio network system

Abstract

An audio network system allows any two nodes among a plurality of nodes to transmit and receive audio data to and from each other. The plurality of the nodes are connected in loop so as to allow transmission of the audio data in loop manner through the plurality of the nodes, and the transmission of the audio data is performed in one direction from an upstream node to a downstream node. One of the plurality of the nodes is set as a master node and the other nodes are set as slave nodes. The master node periodically transmits a packet of frame data containing the audio data every sampling period, such that the packet transmitted from the master node circulates through the plurality of the nodes to return to the master node within one or more sampling period. The packet has a specific data length and includes an audio data storage region divided into a plurality of blocks corresponding to a plurality of channels, such that each of the blocks stores audio data of the corresponding channel.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 a and 1b illustrate example connection of nodes and example transmission between the nodes when an audio network system according to the present invention is applied.

FIGS. 2 a-2f illustrate the flow of bit data in a packet in an audio network system of this embodiment.

FIG. 3 illustrates a frame data structure of one packet.

FIG. 4 illustrates the configuration of a frame data transmission/reception unit included in each node.

FIG. 5 illustrates a timing diagram of packets at each transmission line.

FIG. 6 is an image diagram illustrating the flow of transmission of audio samples in this embodiment.

FIGS. 7 a and 7b are flow charts illustrating hardware processes in a slave node.

FIGS. 8 a-8c are flow charts and buffer structures illustrating hardware processes in a master node.

FIGS. 9 a and 9b are flow charts of a sampling clock interrupt process and a 1-byte transmission event process in the master node.

Claims

1. An audio network system that comprises a plurality of nodes and that allows any two nodes among the plurality of the nodes to transmit and receive audio data to and from each other, wherein the plurality of the nodes are connected in loop so as to allow transmission of the audio data in loop manner through the plurality of the nodes, and the transmission of the audio data is performed in one direction from an upstream node to a downstream node in the loop,wherein one of the plurality of the nodes is set as a master node and the other nodes are set as slave nodes,wherein the master node periodically transmits a packet of frame data containing the audio data every sampling period, such that the packet transmitted from the master node in each sampling period circulates through the plurality of the nodes to return to the master node within one or more sampling period,wherein the packet has a specific data length and includes an audio data storage region divided into a plurality of blocks corresponding to a plurality of channels, such that each of the blocks stores audio data of the corresponding channel,wherein each of the plurality of the nodes is set with either of a transmission channel which indicates one of the blocks in the packet, or a reception channel which indicates one of the blocks in the packet,wherein each of the slave nodes receives, every sampling period, the packet from an upstream node a block by block basis beginning with a head of the packet, the slave node being operative if a received block of the packet corresponds to a transmission channel set to the slave node for overwriting the received block with audio data that is to be transmitted from the slave node, otherwise the slave node being operative if the received block of the packet corresponds to a reception channel set to the slave node for acquiring audio data from the received block that is to be received by the slave node, and then the slave node starting transmission of the packet to a downstream node after a specific time has passed from the time when the slave node starts reception of the head of the packet,wherein the master node receives, every sampling period, a packet that has returned from a most downstream node a block by block basis beginning with a head of the packet, and constructs each block of a next packet or a packet after the next packet to be transmitted in a next sampling period based on the received packet, the master node being operative if the block of the packet corresponds to a transmission channel set to the master node for overwriting the block with audio data that is to be transmitted from the master node, otherwise the master node being operative if the block of the packet corresponds to a reception channel set to the master node for acquiring audio data from the block that is to be received by the master, and the master node starting transmission of the constructed packet to a downstream node when the next sampling period is initiated,wherein the constructed packet contains audio data same as the audio data contained in the packet based on which the packet is constructed by the master node, andwherein one transmission channel is set to only one node in the audio network system so that the audio data written into a block by the one node is not overwritten by another node during the course of circulating the audio data in the audio network system, and any node in the audio network system can receive the audio data.

2. The audio network system according to claim 1, wherein the packet includes a control data storage region in addition to the audio data storage region so that the control data storage region of the packet is used to allow any two of the plurality of the nodes to transmit and receive control data to and from each other.

3. The audio network system according to claim 1, wherein the packet has a data size and a data structure in accordance with Ethernet standard, and a transmitter, a receiver, and a transmission cable defined by Ethernet standard can be used for the transmission of the packet.

4. The audio network system according to claim 1, wherein the plurality of the nodes are connected to allow loop transmission of the packets, such that the plurality of the nodes are connected in cascade by one line for transmission of the packets in one way, and the plurality of the nodes are connected in cascade by another line for transmission of the packets in the other way.

5. The audio network system according to claim 1, wherein the plurality of the nodes are connected to allow loop transmission of the packets, such that the plurality of the nodes are connected in cascade from a first node to a last node for transmission of packets in one direction, and the last node is connected to the first node for returning the packets to the first node.

6. An audio network system that comprises a plurality of nodes and that allows any two of the plurality of the nodes to transmit and receive audio data to and from each other, wherein the plurality of the nodes are connected in loop so as to allow transmission of the audio data through the loop of the nodes, and the transmission of the audio data is performed in one direction from an upstream node to a downstream node in the loop,wherein one of the plurality of the nodes is set as a master node and the other nodes are set as slave nodes,wherein the master node sequentially transmits a predetermined number of packets of frame data containing the audio data at one sampling period, such that the sequentially transmitted packets in each sampling period circulate through the plurality of the nodes to return to the master node within one or more sampling period,wherein each of the predetermined number of the packets has a specific data length and includes an audio data storage region which is divided into a plurality of blocks corresponding to a plurality of channels so that each of the blocks stores audio data of one channel,wherein each of the plurality of the nodes is set with either of a transmission channel which indicates, or a reception channel which indicates one of the blocks in the packet,wherein each of the slave nodes receives, every sampling period, each of the sequentially transmitted packets from an upstream node a block by block basis beginning with a head of the packet, the slave node being operative if a received block of the packet corresponds to a transmission channel set to the slave node for overwriting the received block with audio data that is to be transmitted from the slave node, otherwise the slave node being operative if the received block of the packet corresponds to a reception channel set to the slave node for acquiring audio data from the received block that is to be received by the slave node, and the slave node transmitting the packet to a downstream node after a specific time has passed from the time when the slave node starts receiving the head of the packet,wherein the master node receives, every sampling period, each of the predetermined number of the packets that has sequentially returned from a most downstream node a block by block basis beginning with a head of each packet, and creates each block of the predetermined number of next packets to be transmitted in a next sampling period based on the received packet, the master node being operative if the block of the packet corresponds to a transmission channel set to the master node for overwriting the block with audio data that is to be transmitted from the master node, otherwise the master node being operative if the block of the packet corresponds to a reception channel of the master node for acquiring audio data from the block that is to be received by the master node, then the master node starting the transmission of the created predetermined number of the next packets to a downstream node when the next sampling period is initiated,wherein the created packet contains audio data same as the audio data contained in the packet based on which the packet is created by the master node, andwherein one transmission channel is set to only one node in the audio network system so that the audio data written into a block by the one node is not overwritten by another node during the course of circulating the audio data in the audio network system, and any node in the audio network system can receive the audio data.

7. The audio network system according to claim 6, wherein at least one of the predetermined number of the packets includes a control data storage region in addition to the audio data storage region so that the control data storage region of the packet is used to allows any two of the plurality of the nodes to transmit and receive control data to and from each other.

8. The audio network system according to claim 6, wherein the packet has a data size and a data structure in accordance with Ethernet standard, and a transmitter, a receiver, and a transmission cable defined by Ethernet standard can be used for the transmission of the packet.

9. The audio network system according to claim 6, wherein the plurality of the nodes are connected to allow loop transmission of the packets, such that the plurality of the nodes are connected in cascade by one line for transmission of the packets in one way, and the plurality of the nodes are connected in cascade by another line for transmission of the packets in the other way.

10. The audio network system according to claim 6, wherein the plurality of the nodes are connected to allow loop transmission of the packets, such that the plurality of the nodes are connected in cascade from a first node to a last node for transmission of packets in one direction, and the last node is connected to the first node for returning the packets to the first node.