| 摘要 |
A network-based digital public address system is provided to packetize a digital sound source signal with a control data signal and transmit the created data packet in a standard TCP/IP(Transmission Control Protocol/Internet Protocol) method, thereby having no loss of a signal caused by noise and being adaptive to an increase of nodes. A network-based digital public address system includes a sound source input unit(100), a network control unit(20), and a network signal amplification unit(600). The network control unit includes a network controller(200) and a control computer(300). The network signal amplification unit includes at least one network amplifier(500). The control computer selects a broadcasting area and a broadcasting receiving final terminal, creates a control signal which includes broadcasting target information comprised of Mac address about an amplifier for performing corresponding broadcasting and an 8CH-channel address about a final node speaker for outputting corresponding broadcasting, and transmits the control signal through an Ethernet network. The network controller receives an analog audio signal for broadcasting, converts the analog audio signal into a digital audio signal, assembles the digital audio signal with the control signal into a non-compressed Ethernet packet, and transmits the non-compressed Ethernet packet through the Ethernet network. At least one network amplifier is distributed and arranged to each area, receives the Ethernet packet transmitted from the network controller by using the Mac address of own instinct address information, separates the audio signal and the control signal from the Ethernet packet, and outputs the audio signal to lower final speakers selectively according to node control by the channel address included into the control signal. |
