JP2014060735A - Relay device and communication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a communication system capable of relaying communication with immediacy and responsiveness, utilizing the characteristics of radio communication equipment through a network.SOLUTION: A relay device includes: a network interface connected to a network which is a data communication network; a radio equipment interface to which a transceiver, which is a half-duplex radio communication equipment, is connected; a voice packet receiver unit for receiving a voice packet input from the network interface; a decoder unit for converting the voice packet received by the voice packet receiver unit to an audio signal to output through the radio equipment interface; a downward level detector unit for detecting the audio signal level decoded by the decoder unit; and a PTT control unit for outputting through the radio equipment interface a PTT signal which is a signal to switch the transceiver to a transmission mode at the detection of the audio signal level exceeding a first threshold.

Description

  The present invention relates to a relay device and a communication system for relaying communication of a transceiver through a network.

  RTP (Real-time Transport Protocol: Real-time Transport Protocol), which is generally used as a procedure for transmitting a voice signal in real time via a network, is usually a SIP (Session Initiation Protocol): a session control protocol. It is applied to VoIP (Voice over Internet Protocol) technology such as an IP telephone in combination with an initiation protocol (for example, Patent Document 1).

Japanese Patent No. 4074633

  There is also a demand for relaying communication by a wireless communication device (transceiver) through a network. As a result, wide-area communication can be performed with a low-power transceiver, and communication with a communication device in a place where radio waves are difficult to reach from the outside is also possible.

However, in VoIP technology using SIP, since voice packet transmission / reception is started after calling a specific party using a call procedure, the procedure is troublesome and it takes time to call the other party. There was a problem of lack of immediacy and responsiveness. Also,
There was also a problem that relaying beyond a router or firewall blocking SIP was impossible.

  An object of the present invention is to provide a relay device and a communication system that enable relaying of communication utilizing the characteristics of a wireless communication device via a network.

  The relay device of the present invention receives a network interface connected to a network that is a data communication network, a radio interface that is connected to a transceiver that is a half-duplex radio communication device, and a voice packet input from the network interface. A voice packet receiving unit; a decoding unit that converts a voice packet received by the voice packet receiving unit into an audio signal and outputs the audio signal via a radio interface; and a downlink level detecting unit that detects a level of the audio signal decoded by the decoding unit And a PTT controller that outputs a PTT signal, which is a signal for switching the transceiver to the transmission mode, via the radio interface when it is detected that the level of the audio signal exceeds the first threshold value. It is characterized by having.

  In this invention, the storage unit storing the address of the destination of the voice packet and the audio signal input from the radio interface are packetized, and the voice packet with the address as the destination address is created and output via the network interface A voice packet transmitting unit for detecting the level of the audio signal input from the radio interface, and a PTT control unit for detecting the level of the audio signal input from the radio interface. When it is detected that the threshold value is exceeded, the PTT signal may not be output.

  In the present invention, only when the level of the audio signal input from the radio interface exceeds the second threshold value, the voice packet transmitting unit creates a voice packet and outputs it via the network interface. May be.

  In the present invention, the storage unit may store a multicast address as a destination address.

  The communication system of the present invention is connected to a network that is a data transmission network, a plurality of relay devices connected to the network, and radio interfaces of the plurality of relay devices, and receives received audio signals as relay devices. And a plurality of relay transceivers for inputting audio signals and PTT signals converted from voice packets from the relay device.

  In the present invention, a microphone and a speaker may be connected to some or all of the wireless device interfaces of the plurality of relay devices instead of the relay transceiver.

  According to the present invention, it is possible to relay an immediate and responsive communication utilizing the characteristics of a wireless communication device via a network.

It is a block diagram of the communication system which is embodiment of this invention. It is a block diagram of the relay apparatus of a communication system. It is a figure which shows the memory content of the memory | storage part of a relay apparatus. It is a flowchart which shows operation | movement of the control part of a relay apparatus. It is a block diagram of the communication system which is other embodiment of this invention. It is a block diagram of the relay apparatus of a communication system. It is a figure which shows the memory content of the memory | storage part of a relay apparatus. 4 is a flowchart illustrating an operation of a control unit of the relay device 2. It is a figure which shows the structural example of the multichannel relay apparatus provided with the several unit.

A communication relay device and a communication system of the present invention will be described with reference to the drawings.
FIG. 1 is a configuration diagram of a communication system according to an embodiment of the present invention. This communication system is a system that relays communication of transceivers 4 and 5 that are wireless communication devices via a network 1. As the network 1, for example, a LAN configured by Ethernet (registered trademark) or the Internet can be applied. A plurality of relay apparatuses 2 (2-1, 2-2) are connected to the network 1. Each relay device 2 (2-1, 2-2) is connected to a transceiver 3 (3-1, 3-2) as a relay transceiver. The transceivers 3-1 and 3-2 are so-called Push to Talk (PTT) type wireless communication apparatuses, and the communication form is half-duplex communication. Note that the transceiver 3-1 and the transceiver 3-2 do not need to be of the same type, that is, do not need to be of a type capable of communicating with each other.

  One or a plurality of (two in the figure) transceivers 4 (4-1, 2) exist in the communication area (area A) of the transceiver 3-1. One or a plurality (two in the figure) of transceivers 5 (5-1, 2) are also present in the communication area (area B) of the transceiver 3-2. The transceiver 3-1 and the transceiver 4 and the transceiver 3-2 and the transceiver 5 need to be of a form that can communicate with each other.

  In this communication system, the relay transceiver 3-1 receives and demodulates the radio signal modulated by the voice signal (call voice) transmitted by the transceiver 4 (4-1, 2) in the area A, and the demodulated voice signal. Is input to the relay transceiver 3-2 via the relay device 2-1, the network 1, and the relay device 2-2, and the radio signal superimposed by the relay transceiver 3-2 is transferred to the transceiver 5 ( Send to 5-1 and 2). In this communication system, conversely, the relay transceiver 3-2 receives and demodulates the radio signal transmitted by the transceiver 5 (5-1, 2) in the area B, and the demodulated audio signal is relayed to the relay device 2-. 2, the signal is input to the relay transceiver 3-1 via the network 1 and the relay device 2-1, and the radio signal modulated by the relay transceiver 3-1 using this audio signal is transmitted to the transceiver 4 (4-1, 4-1) Send to 2).

  FIG. 2 is a block diagram of the relay device 2. The relay device 2 includes a radio interface 21 at the downstream end (relay transceiver 3 side) and a network interface 22 at the upstream end (network 1 side). The radio interface 21 has a cable connector, a buffer circuit, and the like that connect the relay transceiver 3. The network interface 22 is a circuit unit in charge of the physical layer and data link layer of the network.

  An A / D converter 23, a VOX (Voice Operation Transmission) processing unit 24, and a voice packet transmitting unit 25 are provided between the radio interface 21 and the network interface 22 in the upstream direction, and voice packets are received in the downstream direction. Section 26, VOX processing section 27, and D / A converter 28. Moreover, the relay apparatus 2 is provided with the control part 20 which is a microcomputer which controls operation | movement of the whole apparatus. The control unit 20 includes a storage unit 20A that stores various data and the like.

FIG. 3 is a diagram showing the configuration of the storage contents of the storage unit 20A. The storage unit 20A stores information such as the local station IP address, the transmission destination IP address, the participating multicast IP address, the local station port number, and the transmission destination port number, which are information for transmitting and receiving voice packets via the network 1. Has been. The transmission destination IP address and the transmission destination port number are destination information attached to the packet when the voice packet (RTP packet) is transmitted to a specific (one) counterpart (relay device 2). Further, when a voice packet is transmitted to a plurality of destinations by multicast, a participating multicast IP address and a transmission destination port number that are IP addresses of participating multicast groups are attached to the RTP packet. The relay device 2 (voice packet receiving unit 26) receives only packets addressed to the local station IP address or participating multicast IP address and designated with the local station port number.
Information stored in the storage unit 20A and whether to use a transmission destination IP address or a participation multicast IP address at the time of transmission are set in advance by an attendant.

  In FIG. 2, the radio interface 21 and the relay transceiver 3 are connected by a so-called microphone cable. The microphone cable is an audio input / output signal line, that is, a speaker signal line for inputting the audio signal received by the relay transceiver 3 to the relay device 2, and outputs an audio signal from the relay device 2 to the relay transceiver 3. A cable having a microphone signal line and a PTT signal line.

  Here, in order to maintain versatility, the relay device 2 is connected only to the microphone cable without exchanging special signals with the relay transceiver 3. Therefore, any transceiver that can be externally connected with a microphone cable can be used as the relay transceiver 3 by connecting to the relay device 2 regardless of the model.

  The radio interface 21 inputs the audio signal input from the relay transceiver 3 to the A / D converter 23. The A / D converter 23 converts the input audio signal into a digital signal and inputs the digital signal to the VOX processing unit 24 and the voice packet transmission unit 25.

  The VOX processing unit 24 monitors the level of the audio signal input from the relay transceiver 3. When the level of the audio signal exceeds a predetermined threshold, an upstream transfer request signal is output to the control unit 20 as upstream speech. This is because when the level of the audio signal input from the relay transceiver 3 exceeds a predetermined threshold value, it is determined that the relay transceiver 3 has received the audio signal from the transceiver 4 and input it to the relay device 2. .

  When the uplink transfer request signal is input from the VOX processing unit 24, the control unit 20 outputs a packet transmission instruction signal to the voice packet transmission unit 25 in order to send the uplink voice signal to the network 1. At this time, the control unit 20 reads out the destination IP address, the destination port number, and the like, which are destination information, from the storage unit 20A and outputs them to the voice packet transmitting unit 25.

  When a packet transmission instruction signal and destination information are input, the voice packet transmission unit 25 converts the voice signal input from the A / D converter 23 into a voice packet and sends it to the network 1. The voice packet transmitter 25 divides the input voice signal into RTP packets, adds an RTP / UDP / IP header to this packet, and outputs the packet to the network interface 22. At this time, the destination IP address or the like is not acquired from the network, but the destination IP address or the like stored in advance in the storage unit 20A is used. Therefore, when a voice signal is input from the relay transceiver 3, An audio signal can be sent to the network 1.

  Note that the presence / absence of uplink audio by the VOX processing unit 24 may be determined with a slight time width in order to prevent chattering and erroneous detection. Alternatively, the presence or absence of voice may be determined by narrowing the voice signal to the frequency band to which the call voice signal belongs.

  Since it takes some time for the VOX processing unit 24 to determine the presence or absence of the uplink voice, a delay unit that delays the voice signal is inserted between the A / D converter 23 and the voice packet transmission unit 25 so that the voice is transmitted. You may make it eliminate the time lag of a signal and a determination result.

  The voice packet receiving unit 26 constantly monitors the reception of voice packets from the network 1, and is open for communication for the local station IP address or participating multicast IP address among the packets received from the network 1. Select and receive packets addressed to the local station port number. When receiving the voice packet, the voice packet receiving unit 26 inputs the voice packet to the control unit 20 and demodulates the voice signal (stream signal) by combining the voice packets. This audio signal is input to the VOX processing unit 27 and the D / A converter 28. The D / A converter 28 converts the input digital audio signal into an analog signal and inputs the analog signal to the radio interface 21. This audio signal is input to the relay transceiver 3 via a microphone cable.

  The VOX processing unit 27 monitors the level of the voice signal input from the voice packet receiving unit 26. When the audio signal exceeds a predetermined threshold, the VOX processing unit 27 outputs a downlink transfer request signal to the control unit 20 as having downlink audio.

  When the downlink transfer request signal is input from the VOX processing unit 27, the control unit 20 outputs a PTT signal to the radio interface 21. The PTT signal is input to the relay transceiver 3 via the microphone cable. The relay transceiver 3 is switched to the transmission mode by the PTT signal, and transmits the audio signal input via the microphone cable to the transceivers 4 and 5 while superimposing it on the transmission radio wave.

  Note that the presence / absence of downstream voice by the VOX processing unit 27 may be determined with a slight time width in order to prevent chattering and erroneous detection. Alternatively, the presence or absence of voice may be determined by narrowing the voice signal to the frequency band to which the call voice signal belongs.

  Since it takes some time for the VOX processing unit 27 to determine the presence or absence of downstream audio, a delay unit that delays the audio signal is inserted between the audio packet receiving unit 26 and the D / A converter 28 to generate audio. You may make it eliminate the time lag of a signal and a determination result.

  As described above, in this communication system, the relay device 2 (2-1, 2-2) immediately transmits a voice packet (RTP packet) to the network in response to the input of the voice signal from the relay transceiver 3, When a voice packet is received from the network, the voice packet is converted into an audio signal and input to the relay transceiver 3 to be transmitted within the area. Thereby, the users of the transceivers 4 and 5 can perform communication via the network in the same manner as normal wireless communication in which the PTT switch is turned on to talk and the PTT switch is turned off to listen to the other party's voice.

  FIG. 4 is a flowchart showing the monitoring operation of the control unit 20 of the relay apparatus 2. This monitoring operation is repeatedly executed every predetermined time (one frame time). The control unit 20 monitors the input of transfer request signals from the VOX processing units 24 and 27 (S11, S12). When an upstream transfer request signal is input from the VOX processing unit 24 (YES in S11), the destination IP address (group ID), port number, etc. are read from the storage unit 20A (S14), and these are transmitted to the voice packet transmission unit 25. The audio signal input from the A / D converter 23 is transmitted to the network 1. The operations in S11, S14, and S15 are operations in the transmission mode. The operation in the transmission mode is executed continuously for one frame time.

  On the other hand, when a downlink transfer request signal is input from the VOX processing unit 27 (YES in S12), a PTT signal is output to the radio interface 21 (S16). As a result, the audio signal received via the network 1 and converted into an analog signal is transmitted from the relay transceiver 3. The operations in S12 and S16 are operations in the reception mode. The operation in the reception mode is executed continuously for one frame time.

  If no transfer request signal is input from both VOX processing units 24 and 27 (NO in S11 and S12), no processing is performed (PTT signal is not output: S13), and both uplink and downlink are performed. Continue monitoring.

  As shown in this flowchart, the uplink transfer request signal (transmission mode) has priority over the downlink transfer request signal (reception mode). That is, when the input of the audio signal from the relay transceiver 3 and the input of the audio signal from the network 1 are performed at the same time, the process of sending the audio signal input from the relay transceiver 3 to the network 1 is prioritized. The audio signal received from the network 1 is not transmitted from the relay transceiver 3. This is a process corresponding to the fact that the half-duplex communication transceiver cannot receive a signal from the counterpart device during transmission.

  In S12 → S16 in the flowchart of FIG. 4, the PTT signal is output when the downlink transfer request signal is input. However, the PTT signal is output on condition that a voice packet is input from the network 1. You may do it.

  In the flowchart of FIG. 4, when the voice packet is transmitted by unicast, the audio signal (may be silent) input from the radio interface 21 is not passed through the procedures of S11, S14, and S15. A configuration in which packets are always packetized and continuously transmitted to the network 1 may be employed. In this case, the receiving side may output the PTT signal based on the signal level of the input voice packet exceeding a predetermined threshold value.

  When the squelch release signal can be input from the relay transceiver 3, the input of the squelch release signal may be monitored together with the upstream transfer request signal (or instead of the upstream transfer request signal) in S11 of the flowchart. .

  Although FIG. 1 shows a configuration in which two relay apparatuses 2 are connected to the network 1, the number of relay apparatuses 2 is not limited to two. In addition, a microphone and a speaker may be connected to the wireless interface 21 of the relay device instead of the relay transceiver 3, and communication via the network 1 may be performed using the relay device 2 instead of the transceiver.

  FIG. 5 is a diagram showing a configuration of a communication system according to another embodiment of the present invention. In this figure, the same components as those in the communication system shown in FIG. In this communication system, a relay device 12 is further connected to the network 1 of the communication system of FIG. The emergency broadcast receiver 6 and the microphone 7 (and the speaker 8) are directly connected to the relay device 12. In other words, the relay device 12 is directly connected to the emergency broadcast receiver 6 and the microphone 7 which are devices that themselves output a target audio signal, instead of the relay transceiver 3 that relays wireless communication.

  Note that the relay device 12 may be connected to a speaker 8 for reproducing a voice packet received from the network 1.

  In this communication system, each relay device 2 has its own station set for communication that should be received preferentially, such as emergency communication, in addition to its own port number used for normal communication (own station normal port number). The local station priority port number that is the port number is set. Then, the relay device 12 transmits the audio signal input from the emergency broadcast receiver 6 or the microphone 7 to the priority port of each relay device 2 as an audio signal to be received with priority, and prioritizes other communication audio. Then, the transceivers 4 and 5 are made to receive.

  FIG. 6 is a block diagram of the relay device 12. In this figure, parts having the same configurations as those of the relay apparatus 2 shown in FIG. The relay device 12 has substantially the same configuration as the relay device 2, but when the speaker 8 is not connected to the interface 21 ', there is no device for reproducing the voice packet received from the network 1, and thus the downstream system device is not necessarily used. Not necessary. In the relay apparatus 2 of FIG. 2, the PTT signal is input from the control unit 20 to the radio interface 21. However, in the relay apparatus 12, the PTT signal of the microphone 7 is transmitted from the interface 21 'to the control unit 20. It is good also as a structure input with respect to. This OTT signal can be used as a trigger signal for a packet transmission instruction to the voice packet transmitter 25 instead of the upstream transfer request signal of the VOX processor 24.

  Since the relay device 12 can be realized with the same hardware configuration as the relay device 2, the relay device 2 and the relay device 12 may be used together by changing settings of software or the like on the same device.

  FIG. 7 is a diagram illustrating the contents stored in the storage unit 20 </ b> A of the relay device 2 and the relay device 12. FIG. 4A shows the stored contents of the relay device 2. FIG. 5B shows the stored contents of the relay device 12. In this figure, the description of the same stored contents as in FIG. 3 is omitted.

  7A, in the storage unit 20A of the relay apparatus 2, the local station IP address, the transmission destination IP address, the participating multicast IP address, the local station normal port number (21500), the local station priority port number (21600), Information such as a transmission destination port number (21500) is stored. The local station normal port number is a port number used during normal communication. When a voice packet is received at this port number, the control unit 20 performs the same processing as in the flowchart shown in FIG. The local station priority port number is a port number used for priority broadcasting such as emergency broadcasting. When a voice packet is received at this port number, the control unit 20 prioritizes other communication (transmission / reception). The voice signal is received.

  7B, in the storage unit 20A of the relay device 12, the local station IP address, the participating multicast IP address, the local station normal port number (21500), the local station priority port number (21600), the destination port number ( 21600) is stored. This apparatus is set in advance to transmit a voice packet toward a multicast IP address and toward a priority port number (21600). Therefore, the voice packet transmitted from the relay device 12 is preferentially received by the other relay device 2. In addition, the normal port number and the priority port number shown in this figure are examples, and are not limited to these numbers.

  FIG. 8 is a flowchart showing the operation of the control unit 20 of the relay device 2 in the communication system of FIG. In this figure, the same steps as those in the flowchart shown in FIG. 4 are denoted by the same step numbers (S numbers), and description thereof is omitted. In S10, packet input from the priority port is monitored. When a packet is input from the priority port, the PTT signal is preferentially output without determining the volume of the voice packet and without determining the signal level of the other VOX processing units 24 and 27 (S16). ). Thus, when a signal from the priority port is input, the signal is preferentially input to the relay transceiver 3 and transmitted to the transceivers 4 and 5. Thereby, emergency broadcast etc. can be transmitted toward all the transceivers 4 and 5 in preference to other communications.

  In this embodiment, the priority port number is determined and the voice packet arriving at the priority port is defined as the “specific voice packet” of the present invention. However, communication is performed at a normal port and a specific mark is given to the voice packet. The “specific voice packet” can also be used.

  The relay device 12 may execute the operation shown in the flowchart of FIG. 8, but may execute the operation shown in the flowchart of FIG. 4 without monitoring the priority port number. In this case, in the operation of S11, the input of the PTT signal from the microphone 7 may be monitored together with the uplink transfer request signal (or instead of the uplink transfer request signal).

  FIG. 9 is a diagram illustrating a configuration example of a multi-channel relay device in which a plurality of relay devices 2 and 12 having the configurations illustrated in FIGS. 2 and 6 are provided as a unit. The relay device of this figure includes three radio relay units 31 having the configuration of the relay device 2 of FIG. 2, and one receiver relay unit 32 having the configuration of the relay device 12 of FIG. Furthermore, a network interface 34 that controls communication between the relay units 31 and 32 and the network 1 and a broadcast device interface 35 that includes an audio circuit that outputs an audio signal to broadcast (speech) equipment are provided. A patch bay 33 for controlling input / output of audio signals is provided.

  By providing a plurality of radio relay units 31, this relay apparatus can relay radio communications in a plurality of areas with a single apparatus. In addition, it is possible to relay between areas within this apparatus without going through the network 1. Also, transceivers of different styles (for example, different communication frequencies) are connected to each radio relay unit 31-1, 2, 3 and installed in the same area, so that different styles of transceivers exist in the same area. Communication between those transceivers is possible.

1 network 2,12 relay device 3 relay transceiver 4,5 transceiver

Claims (6)

A network interface connected to a network which is a data communication network;
A radio interface to which a transceiver that is a half-duplex radio communication device is connected;
A voice packet receiver for receiving voice packets input from the network interface;
A decoding unit that converts the voice packet received by the voice packet receiving unit into an audio signal and outputs the audio signal via the radio interface;
A downstream level detection unit for detecting the level of the audio signal decoded by the decoding unit;
A PTT control unit that outputs a PTT signal, which is a signal for switching the transceiver to a transmission mode, via the radio interface when it is detected that the level of the audio signal exceeds a first threshold;
A relay device comprising: A storage unit that stores the destination address of the voice packet;
A voice packet transmitter that packetizes an audio signal input from the radio interface, creates a voice packet with the address as a destination address, and outputs the voice packet via the network interface;
An upstream level detector for detecting the level of an audio signal input from the radio interface;
Further comprising
The relay apparatus according to claim 1, wherein the PTT control unit does not output the PTT signal when it is detected that the level of an audio signal input from the radio interface exceeds a second threshold value. .   The voice packet transmitting unit creates the voice packet and outputs the voice packet via the network interface only when the level of the audio signal input from the radio interface exceeds the second threshold value. Item 3. The relay device according to Item 2.   The relay apparatus according to claim 3, wherein the storage unit stores a multicast address as a destination address. A data transmission network,
A plurality of relay apparatuses connected to the network, the relay apparatus according to any one of claims 2 to 4;
A plurality of relays connected to the radio interfaces of the plurality of relay apparatuses, respectively, and outputting received audio signals to the relay apparatus and inputting audio signals converted from the voice packets and the PTT signals from the relay apparatus Transceiver for
A communication system comprising:   The communication system according to claim 5, wherein a microphone and a speaker are connected to a part or all of the plurality of relay apparatuses in place of the relay transceiver.

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