JP2003101579A - Transmitter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a transmitter for performing a multi-path redundancy transmission to moderate a transmission delay with a simple constitution. SOLUTION: The transmitter comprises a sound packet producing unit for outputting sound packets after packetizing received sound signals, a data packet producing unit for outputting data packets after packetizing received data signals, a packet duplicating unit for duplicating respective packets received from both of the sound packet producing unit and the data packet producing unit, and a first line interface for respectively outputting a plurality of the packets each duplicated by the packet duplicating unit into a plurality of paths different with each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission device for redundantly sending and transmitting packets to multiple routes, and more particularly to a transmission device for redundantly transmitting voice data input from a telephone or the like with as little delay as possible.

[0002]

2. Description of the Related Art FIG. 6 is a schematic explanatory view for explaining a general multi-way redundant transmission system. In the figure, 4a
4a to 4c are multi-way redundant transmission devices, 5a to 5c are digital terminals that output digital signals, and K3 is a multi-way redundant transmission device 4c from the multi-way redundant transmission device 4a to the multi-way redundant transmission device 4c. , K4 is a second route from the multi-way redundant transmission device 4a to the multi-way redundant transmission device 4c without passing through the multi-way redundant transmission device 4b.

The operation will be described. The multi-way redundant transmission device 4a packetizes the digital signal from the digital end 5a and routes the packet to the route K3 and the route K4.
Output to two routes. The multi-way redundant transmission device 4c receives this packet from both the routes of the route K3 and the route K4, extracts a digital signal from the received packet, and outputs the digital signal to the digital terminal not yet 5c. By redundantly transmitting the same packet to the communication partner device via a plurality of routes in this way, the packet can be reliably transmitted even when any of the routes is disconnected.

[0004]

However, such a multi-way redundant transmission system is complicated in processing as compared with a transmission method which is usually performed only through a single route.
There is a problem that the device becomes large or transmission delay easily occurs.

Further, the conventional multi-way redundant transmission device is not designed in consideration of voice transmission requiring high quality of service (QOS), and in particular, no measures are taken against interruption of conversation due to transmission delay. Was not applied.

The present invention has been made in order to solve the above problems, and provides a transmission device which is less likely to cause a transmission delay and which can be miniaturized by sharing a circuit. In addition, a transmission device suitable for voice transmission is obtained.

[0007]

In a transmission apparatus according to the present invention, an audio packet generator for packetizing an input audio signal and outputting an audio packet, and an input data signal for packetizing the data packet. The output data packet generation unit, the packet duplication unit that duplicates the packets input from the voice packet generation unit and the data packet generation unit, and the plurality of packets generated by the duplication processing in the packet duplication unit to different routes. And a first line interface for outputting.

Further, in the transmission apparatus according to the present invention, when the destinations of the voice packet output by the voice packet generator and the data packet output by the data packet generator are the same, the voice packet and the data packet are multiplexed. The packet duplication unit duplicates the packet after the multiplexing process in the multiplexing circuit.

Further, in the transmission apparatus according to the present invention, the second line interface for receiving the packets multiplexed from a plurality of different routes and the packet received from the plurality of different routes are duplicated. If there is a packet that is received by the redundant packet processing unit, the redundant packet processing unit that selects and outputs one of the redundantly received packets and the packet that the redundant packet processing unit outputs is demultiplexed. Demultiplexing circuit for outputting a voice packet and a data packet, a voice packet decomposition unit for extracting a digital voice signal from the voice packet, and accumulating the extracted digital voice signal,
A delay compensation circuit that sequentially outputs the accumulated digital audio signals and interrupts the output of the accumulated digital signals when the accumulated digital signals are below a predetermined amount, and a digital audio signal output by the delay compensation circuit And an A / D conversion unit for A / D converting and outputting an analog audio signal.

Furthermore, in the transmission device according to the present invention, the audio signal is input via the two-wire line.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1. 1 is a configuration diagram illustrating a multi-way redundant transmission device according to a first embodiment of the present invention. An analog terminal 21 such as a telephone is connected to the multi-way redundant transmission device 1 via a two-wire transmission line 28, and a digital terminal 3 such as a computer is not connected.
1 is connected via a digital transmission line 37.

Further, here, the communication partner whose analog end is not 21 is preset and stored in the analog end untransmitted destination output section 25 described later, and the communication partner whose digital end is not 31 is the digital end 31. It is assumed that the digital end unsent destination output unit 36 is set and stored in advance.

First, the circuit configuration of the transmission system of the multi-way redundant transmission apparatus 1 will be described. In FIG. 1, reference numeral 22 denotes a 2-wire to 4-wire converting unit, which outputs an analog audio signal input via the analog 2-wire type transmission line 28 to an A / D converting unit 23 which will be described later, and D / which will be described later. A converter 2
The analog voice signal input from 7 is output to the analog two-wire transmission line 28. Reference numeral 23 is an A / D conversion unit that converts the analog audio signal from the 2-line to 4-line conversion unit 22 into ADPCM.
(Adaptive Differential PCM) conversion to a digital audio signal. Reference numeral 25 denotes an analog end unsent destination output unit, which outputs an identification symbol of the analog end not yet 21 to which the communication partner end is not present as a destination address. Reference numeral 24 is a voice packet generator, which converts the digital voice signal from the A / D converter 23 into packets, and the packet type, source address, and destination address from the analog end untransmitted destination output unit 25 in the header of the packet. Write etc.

Reference numeral 32 is a receiving system format converting section, which converts the digital data signal from the digital terminal 31 into a predetermined format and outputs it. Reference numeral 33 is a data packet generation unit, which is a reception system format conversion unit 3
The digital data signal output by 2 is packetized, and the packet type, the source address, the destination address, etc. are written in the header of the packet. The destination address written in this header is an identification symbol output from the digital end unsent destination output unit 36 to indicate that the communication partner end has not yet been reached.

Reference numeral 11 denotes a multiplexing circuit which, when the destination address of the voice packet output from the voice packet generator 24 and the destination address of the data packet output from the packet generator 33 are the same. The packets are multiplexed and output as a single packet having a common destination address (for example, FIG. 2). If the destination addresses do not match, the multiplexing is not performed, and each packet is output as a single packet as it is. Reference numeral 12 is an identification symbol assigning unit that writes an identification symbol (hereinafter referred to as a packet identification symbol) unique to each packet in the header of the packet output from the multiplexing circuit 11. Reference numeral 13 is a packet duplication unit that duplicates the packet in which the packet identification symbol is written and outputs a plurality of identical packets. Reference numeral 14 is a redundant route determining unit that writes different route information in the header of each packet so that the same packet duplicated in the packet duplicating unit 13 reaches the communication partner end via different routes. Reference numeral 15 denotes a transmission system line interface, which distributes the packet from the redundant route determination unit 14 and the packet from a reception system line interface 16 described later to each route based on the route information written in the header.

Next, the circuit configuration of the receiving system of the multi-way redundant transmission apparatus 1 will be described. Reference numeral 16 is a receiving system line interface, which refers to the destination address of the packet received from each route, and refers to a packet addressed to the own device (end not connected to the own device) for a redundant packet discarding unit 17 described later.
A packet addressed to another device is output to the transmission line interface 15. Reference numeral 17 denotes a redundant packet discarding unit, which discards duplicated packets output from the receiving circuit interface 16 and outputs packets having different packet identification symbols one by one to a packet separating circuit 18 described later. . A packet separation circuit 18 separates the packet from the redundant packet discard unit 17 into a voice packet and a data packet, that is, demultiplexes them.

Reference numeral 26 is a voice packet decomposing unit, which extracts a digital voice signal from the voice packet from the packet separating circuit 18 and outputs it. Reference numeral 27 denotes a D / A conversion unit, which D / A converts the digital voice signal from the voice packet decomposition unit 26 and outputs it to the 2-line to 4-line conversion unit 22 as an analog voice signal. A data packet decomposing unit 34 extracts a digital data signal from the data packet from the packet separating circuit 18 and outputs it. Reference numeral 35 is a transmission system format conversion unit, which is a data packet decomposition unit 3
The digital data signal output from the digital converter 4 is converted into a predetermined format and output to the digital terminal 31.

Here, the identification symbol assigning unit 12, the packet duplicating unit 13, and the redundant route determining unit 14 constitute a transmitting system multi-way redundancy control unit 61, and the redundant packet discarding unit 17 forms a receiving system multi-way route. The redundancy control unit 62 is configured. Also, the analog end 21 and the two-wire type transmission line 28,
2-line to 4-line conversion unit 22, A / D conversion unit 23, voice packet generation unit 24, analog end unsent destination output unit 25
, The voice packet disassembling unit 26, and the D / A converting unit 27 constitute the analog end part 2 and the digital end part 31.
The digital end unsent destination output unit 36, the digital transmission line 37, the reception system format conversion unit 32, the packet generation unit 33, the data packet decomposing unit 34, and the transmission system format conversion unit 35, Part 3
Is configured.

Next, the operation of the multi-way redundant transmission device 1 will be described. The analog voice signal output from the analog terminal 21 is a 2-wire type transmission line 28 and a 2-wire to 4-wire converting section 2.
2 is transmitted, and is converted into a digital voice signal by the A / D converter 23, and converted into a voice packet including the destination address by the voice packet generator 24. On the other hand, the digital data signal output from the digital terminal 31 is
The reception system format conversion unit 32 converts the format, and the data packet generation unit 33 converts the data packet including the destination address. The multiplexing circuit 11 includes the voice packet generator 24 and the data packet generator 3
When the destination addresses of the packets output from 3 match, they are multiplexed and output as a single packet. Each packet multiplexed in the multiplexing circuit 11 has a packet identification symbol written in the identification symbol assigning unit 12 and is duplicated in the packet duplicating unit 13. In each of the packets thus duplicated, the route information is written by the redundant route determination unit 14, and the transmission system line interface 1
It is output to a different route via 5.

A packet transmitted from another device to its own device is received by the receiving line interface 16, the redundant packet discarding unit 17 discards the duplicate packet, and the packet separating circuit 18 discards the voice packet. And a data packet. The voice packet separated by the packet separation circuit 18 is sent to the voice packet decomposition unit 26.
Is decomposed into a digital audio signal, converted into an analog audio signal in the D / A conversion unit 27, and transmitted to the analog end 21 through the 2-wire to 4-wire conversion unit 22 and the 2-wire transmission line 28. To be done. Further, the data packet separated by the packet separation circuit 18 is decomposed by the data packet decomposition unit 34 and converted into a digital data signal, converted into a predetermined format by the transmission system format conversion unit 35, and the digital terminal 36 Transmitted up to.

FIG. 3 is a diagram illustrating a transmission system configured by using the multi-way redundant transmission device shown in FIG. In the figure, 1a to 1c are first to third multi-way redundant transmission devices having the same configuration as the multi-way redundant transmission device 1 shown in FIG. 1, and 21a to 21c are multi-way redundant transmission devices 1a to 1c, respectively. Connected first to third analog terminals, 31a
31c are digital terminals not connected to the multi-way redundant transmission apparatuses 1a to 1c, respectively, and K1 is a multi-way redundant transmission apparatus 1
The first route from a to the multi-way redundant transmission apparatus 1c via the multi-way redundant transmission apparatus 1b, K2 is from the multi-way redundant transmission apparatus 1a to the multi-way redundant transmission apparatus 1c without the multi-way redundant transmission apparatus 1b. This is the second route to reach. As described above, in the first embodiment, the audio signal output by the analog terminal 21a and the data signal output by the digital terminal 31a are
The multi-way redundant transmission device 1a multiplexes and duplicates, and transmits to the multi-way redundant transmission device 1c via different routes K1 and K2.

As described above, in the first embodiment,
Since the voice packet generated from the output without analog end and the data packet generated from the output without digital end are input to the common transmission system multi-way redundancy control unit 61 as shown in FIG. The structure is simplified and an inexpensive device can be obtained.

Further, in the multi-way redundant transmission apparatus of the first embodiment, when the destination addresses of the respective packets generated from the output without the analog end and the output without the digital end are the same, they are singled out. Multiple packets,
Since the multi-way redundancy control is performed for the multiplexed packets, the processing in the transmission system multi-way redundancy control unit 61 and the reception system multi-way redundancy control unit 62 can be reduced, and the transmission delay can be suppressed. it can. Especially high Qo
It is possible to obtain a multi-way redundant transmission apparatus suitable for voice transmission that requires s (quality of service).

Further, in the multi-way redundant transmission device of the first embodiment, since the transmission line for inputting the output not yet at the analog end is a two-wire type, it is possible to connect a popular telephone. it can.

Although FIG. 1 illustrates the case where the analog end portion 2 and the digital end portion 3 are connected to the multiplexing circuit 11 one unit each, the multiplexing is performed as illustrated in FIG. 4, for example. A plurality of analog terminals 2 and / or a plurality of digital terminals 3 may be connected to the circuit 11. Note that, in FIG. 4, the same or corresponding parts as in FIG. Further, in the figure, 2a to 2c are analog end parts 2 shown in FIG.
First to third analog end parts 3a having the same structure as
3c are first to third digital end portions having the same configuration as the digital end portion 3 shown in FIG.

In FIG. 1, an IP (internet protocol) terminal for outputting a digital audio signal in a TCP / IP (transmission control protocol) format is used as the analog terminal 2 and / or the digital terminal 3 not shown. Good.

Further, here, the case where the analog end untransmitted destination output unit 25 stores the communication end of the analog end not yet 21 in advance has been described, but the present invention is not limited to this. For example, the analog end not transmitted. The first output unit 25 may recognize the communication partner based on the dial signal transmitted from the analog terminal 21. Similarly, it is also possible to specify that the communication partner end has not been sent to the digital end unsent destination output unit 36 by any input means. In addition, the transmission line interface 15 and the reception line interface 1
The plurality of routes output by 6 may be either wireless lines or wired lines.

Embodiment 2. FIG. 5 is a configuration diagram illustrating a multi-way redundant transmission device according to the second embodiment. In the figure, the same or corresponding parts as in FIG. Here, the voice packet decomposition unit 26 and D /
A delay compensation circuit 29 is provided between the A conversion unit 27 and the A conversion unit 27. The delay compensating circuit 29 is a buffer composed of a FIFO memory or the like, accumulates the digital audio signals from the audio packet decomposing unit 26 and sequentially outputs them to the D / A converting unit 27, and the accumulated amount thereof is a predetermined amount. When it decreases more than that, the audio signal output to the D / A conversion unit 27 is stopped until the accumulated amount increases. As a result, it is possible to suppress the sound quality deterioration due to the transmission delay of the voice packet.

[0029]

Since the present invention is constructed as described above, it has the following effects. In the transmission device according to the present invention, a voice packet generator that packetizes an input voice signal and outputs a voice packet, a data packet generator that packetizes an input data signal and outputs a data packet, and a voice A packet duplication unit that duplicates the packets input from the packet generation unit and the data packet generation unit, and a first line interface that outputs a plurality of packets generated by the duplication processing in the packet duplication unit to different routes. Since it is provided, the voice packet generation unit and the data packet generation unit can share the packet duplication unit of the output destination, and a small-sized and low-cost transmission device can be obtained.

Further, in the transmission apparatus according to the present invention, when the destinations of the voice packet output by the voice packet generator and the data packet output by the data packet generator are the same, the voice packet and the data packet are multiplexed. Further, since the packet duplication unit duplicates the packet after the multiplexing process in the multiplexing circuit, the duplication process is reduced as compared with the case where the voice packet and the data packet are independently duplicated. Therefore, it is possible to obtain a transmission device that is small and has a small audio transmission delay.

Further, in the transmission apparatus according to the present invention, the second line interface for receiving the multiplexed packets from the different routes and the packet received from the different routes are duplicated. If there is a packet that is received by the redundant packet processing unit, the redundant packet processing unit that selects and outputs one of the redundantly received packets and the packet that the redundant packet processing unit outputs is demultiplexed. Demultiplexing circuit for outputting a voice packet and a data packet, a voice packet decomposition unit for extracting a digital voice signal from the voice packet, and accumulating the extracted digital voice signal,
A delay compensation circuit that sequentially outputs the accumulated digital audio signals and interrupts the output of the accumulated digital signals when the accumulated digital signals are below a predetermined amount, and a digital audio signal output by the delay compensation circuit Since the A / D conversion unit for A / D converting and outputting an analog voice signal is provided, the number of interruptions of the analog voice signal can be reduced.

Furthermore, in the transmission apparatus according to the present invention, since the voice signal can be input via the two-wire line, the transmission which can transmit the analog voice signal output from a general telephone set. The device can be obtained.

[Brief description of drawings]

FIG. 1 is a configuration diagram illustrating a multi-way redundant transmission device according to a first embodiment.

FIG. 2 is a diagram for explaining the operation of the multiplexing circuit of FIG.

FIG. 3 is a diagram illustrating a transmission system configured by using the multi-way redundant transmission device shown in FIG.

FIG. 4 is a diagram showing another example of the multi-way redundant transmission device according to the first embodiment.

FIG. 5 is a configuration diagram illustrating a multi-way redundant transmission device according to a second embodiment.

FIG. 6 is a diagram illustrating a general multi-way redundant transmission system.

[Explanation of symbols]

1 multi-way redundant transmission device, 2 analog end part, 3
Digital end part, 11 Multiplexing circuit, 12 Identification mark giving part, 13 Packet duplicating part, 14 Redundant route determining part, 15 Transmission line interface, 16
Receiving system line interface, 17 redundant packet discarding unit, 18 packet separation circuit, 21 analog end not yet, 22 2-wire to 4-wire converting unit, 23 A / D converting unit, 24 voice packet generating unit, 25 analog end not transmitting destination output Section, 26 voice packet disassembling section, 27
D / A converter, 28 2-wire transmission line, 29 delay compensation circuit, 31 digital end not included, 32 receiving format converter, 33 data packet generator, 3
4 data packet disassembly unit, 35 transmission format conversion unit, 36 digital end unsent destination output unit, 3
7 digital transmission line, 61 transmission system multi-way redundancy control unit, 62 reception system multi-way redundancy control unit.

Claims (4)

[Claims] 1. A voice packet generator that packetizes an input voice signal and outputs a voice packet, a data packet generator that packetizes an input data signal and outputs a data packet, said voice packet generator And a packet duplicating unit that duplicates the packet input from the data packet generating unit, and a first line interface that outputs a plurality of packets generated by the duplication processing in the packet duplicating unit to different routes. A transmission device characterized by the above. 2. A multiplexing method for multiplexing the voice packet and the data packet when the transmission destinations of the voice packet output by the voice packet generation unit and the data packet output by the data packet generation unit are the same. 2. A packetizing circuit is further provided, and the packet duplicating unit duplicates the packet after the multiplexing process in the multiplexing circuit.
The transmission device according to. 3. A second line interface for receiving a packet multiplexed from a plurality of different routes and a packet received duplicately among the packets received from the plurality of different routes. In this case, a redundant packet processing unit that selects and outputs one of the packets received in duplicate, and a packet that is output by the redundant packet processing unit is demultiplexed to a voice packet and a data packet. A demultiplexing circuit for outputting a digital voice signal from the voice packet, a voice packet decomposing unit for extracting the digital voice signal from the voice packet, accumulating the retrieved digital voice signal, sequentially outputting the accumulated digital voice signal, and The delay compensation that interrupts the output of the stored digital signal when the digital signal is less than a predetermined amount. 3. The circuit according to claim 1, further comprising a circuit, and an A / D conversion unit that A / D converts the digital audio signal output by the delay compensation circuit and outputs an analog audio signal. Transmission equipment. 4. The transmission device according to claim 1, wherein the audio signal is input via a two-wire line.