JP5796217B2 - Relay device and communication system - Google Patents

Description

  The present invention relates to a repeater that relays a transmission signal transmitted between terminals, and a communication system including the repeater.

  As a conventional communication system, for example, there is an apartment intercom system described in Patent Document 1. The system described in Patent Document 1 includes a lobby intercom installed at a common entrance of an apartment house, a dwelling unit installed in each dwelling unit, a control device connected between the lobby intercom and the dwelling unit group, and the like. Then, the video captured by the lobby intercom, the voice of the visitor, and the voice of the resident are digitally transmitted to each other via the control device.

  In this conventional system, specifications such as the total number of dwelling units that can be connected to the control device and the longest transmission path distance (maximum transmission distance) are determined in order to ensure communication quality. Therefore, a relay device that relays a transmission signal is provided in the middle of the transmission line in order to connect a number of dwelling units exceeding the specification or to secure a transmission distance exceeding the maximum transmission distance. That is, when viewed from the control device, the relay device corresponds to the same communication terminal as the dwelling unit, and the dwelling unit connected to the end of the relay device and the transmission path are connected to the control device without the relay device. Is considered as a segment different from the segment (network).

JP 2010-178073 A

  By the way, when the isolation performance in the relay device is degraded, a transmission signal may be directly transmitted between two segments that should have been separated by the relay device. Then, the total number of dwelling units connected to the control device and the maximum transmission distance may exceed specifications, and it may be difficult to ensure communication quality.

  In order to avoid such a situation, it is desirable to inspect the isolation performance of the relay device before operating the system, and to implement measures for improving the isolation as necessary. However, when the relay device shares the reception circuit and the transmission circuit for a plurality of transmission paths for cost reduction, it is difficult to inspect the isolation performance unless a signal is input from the outside.

  The present invention has been made in view of the above problems, and an object of the present invention is to prevent deterioration of a transmission signal due to a decrease in isolation performance while sharing a reception circuit and a transmission circuit for a plurality of transmission paths. .

The relay apparatus according to the present invention receives two connection terminals each connected to a different transmission path and a transmission signal transmitted to the transmission path from the connection terminal, and performs a relay process on the received transmission signal. Relay means for transmitting from the connection terminal after inspection, inspection means for inspecting the isolation performance between the two connection terminals, and reception path blocking means for blocking the reception path from one of the connection terminals to the relay means And a notifying means for notifying the inspection result of the inspection means, wherein the relay means serves both as a transmission processing section for transmitting transmission signals to the plurality of transmission paths and a reception processing section for receiving transmission signals. are those, the examination means, transmission the receive path blocking means in a state in which blocking the receive path, the inspection request for than the one connecting terminal to which the receive path is blocked Sends No., transmission signal returned for the transmission signal for the examination request, the inspection of the isolation performance based on whether received at the connecting terminals of said different and one of the connection terminals other It is characterized by performing.

  The communication system according to the present invention is a communication system including the relay device and a plurality of communication terminals respectively connected to the two connection terminals included in the relay device via the transmission path. A transmission request transmission signal is transmitted from the one connection terminal before transmission of the inspection request transmission signal, and the communication terminal transmits a ready transmission signal to the relay device when the transmission request transmission signal is received. The transmission means does not transmit a transmission signal until a predetermined time has passed after the transmission signal is returned, and the inspection means transmits the transmission signal for the inspection request after receiving the transmission signal for completion of preparation. It is characterized by that.

  In this communication system, the inspection unit preferably transmits the transmission signal of the transmission request when the relay unit receives the transmission signal of the inspection start request transmitted from any of the communication terminals.

  The relay device and the communication system of the present invention are designed to prevent deterioration of a transmission signal due to a decrease in isolation performance while sharing a reception circuit (reception processing unit) and a transmission circuit (transmission processing unit) for a plurality of transmission paths. There is an effect that can be.

1 is a system configuration diagram showing an embodiment of a relay device and a communication system according to the present invention. (a), (b) is a circuit diagram of the mixing circuit part in the same as the above. It is a sequence diagram for operation | movement description same as the above. It is a sequence diagram for operation | movement description same as the above. It is a sequence diagram for operation | movement description same as the above.

  Hereinafter, an embodiment in which the technical idea of the present invention is applied to an intercom system for an apartment house and a relay device used therefor will be described in detail. However, the communication system and the relay device to which the technical idea of the present invention can be applied are not limited to the collective housing intercom system, and can be applied to a communication system and a relay device other than the collective housing intercom system.

  As shown in FIG. 1, the intercom system for an apartment house of this embodiment includes a common terminal (lobby interphone) 5 installed at the common entrance (lobby) of the apartment house, and a dwelling unit installed in each unit of the apartment house. The terminal 3, the control device 2, and the relay device 1 are included. The plurality of dwelling unit terminals 3, the lobby intercom 5, and the relay device 1 are connected to the control device 2 through transmission paths each including a balanced two-wire communication cable. However, in FIG. 1, the transmission path between the control device 2 and the lobby intercom 5 is 4C, the transmission path between the control device 2 and the relay device 1 is 4A, and is branched from the transmission path 4A and connected to each dwelling unit 3. Each transmission line is distinguished by attaching a 4D code.

  In addition, a plurality of dwelling unit terminals 3 are connected to the relay device 1 via transmission lines 4B each composed of a balanced two-wire communication cable. A segment (network) to which the dwelling unit terminal 3 directly connected to the control device 2 via the control device 2 and the transmission line 4A belongs is referred to as a first segment S1. On the other hand, the segment (network) to which the dwelling unit terminal 3 connected to the relay device 1 via the transmission line 4B belongs is called a second segment S2.

  The lobby intercom 5 transmits a transmission signal through a transmission line 4C for an image pickup device that picks up an image of a visitor, a microphone and a speaker, a numeric keypad or touch panel for the visitor to input a dwelling unit number of the visited residence, and a voice and video. A transmission unit and the like are provided. In the lobby intercom 5, when the operation input of the dwelling unit number of the dwelling unit is received by operating the touch panel or the like, the packet storing the dwelling unit number in the data field and the video (video information) of the visitor imaged by the imaging device are entered in the data field Generate the stored packet. A transmission signal obtained by digitally modulating these packets is transmitted from the transmission unit to the address of the control device 2 via the transmission line 4C.

  The control device 2 stores a correspondence relationship between addresses assigned to the dwelling unit terminals 3 of all dwelling units and dwelling unit numbers of the dwelling units. And the control apparatus 2 compares the dwelling unit number stored in the data field of the packet received from the lobby intercom 5 with the said correspondence, and converts it into an address. A packet in which the address is stored in the destination address field and a call command for notifying the call from the lobby intercom 5 is stored in the data field and a packet in which the video information is stored in the data field are modulated. A transmission signal is sent from the control device 2 to the transmission line 4A.

  In the dwelling unit 3 installed in the dwelling unit with the dwelling unit number, when a packet (transmission signal) is received via the transmission paths 4A and 4D, a ringing sound is generated from the speaker and the display device such as a liquid crystal display Display video. When the resident who has heard the ringing tone confirms the video of the visitor displayed on the display device of the dwelling unit terminal 3 and operates the response button, the voice of the resident collected by the microphone of the dwelling unit terminal 3 is transmitted. It is transmitted to the control device 2 via the paths 4A and 4D. In the control device 2, a packet (voice packet) transmitted from the dwelling unit terminal 3 is transferred to the lobby intercom 5, and a packet (voice and video packet) transmitted from the lobby intercom 5 is transferred to the dwelling unit terminal 3. . As a result, a resident of the dwelling unit and a visitor can make an interphone call using the dwelling unit terminal 3 and the lobby intercom 5.

  Then, when the response button of the dwelling unit terminal 3 is pressed during the intercom call or when a predetermined time (for example, several minutes) has elapsed from the start of the call, the dwelling unit 3 forcibly ends the intercom call. In the present embodiment, intercom calls can be performed between the dwelling units 3 of different dwelling units via the control device 2, but basically the same procedure as that for intercom calls with the lobby intercom 5 is performed. Therefore, explanation is omitted. Moreover, since the dwelling unit 3 that enables the interphone call as described above is well known in the art, the detailed illustration and description of the configuration are omitted.

  The relay device 1 includes a first connection terminal 10A, a second connection terminal 10B, a mixing circuit unit 11, a reception amplifier 12, an AD converter 13, a reception processing unit 14, a relay processing unit 15, a transmission processing unit 16, a DA converter 17, and a pair Transmission amplifiers 18A and 18B. The first connection terminal 10A is connected to the transmission line 4A, and is connected to the reception end 11A on one side of the mixing circuit unit 11 and the output end of one transmission amplifier 18A. That is, the transmission signal transmitted from the control device 2 is taken into the receiving end 11A of the mixing circuit unit 11 from the first connection terminal 10A via the transmission line 4A. The second connection terminal 10B is connected to the transmission line 4B, and is connected to the reception end 11B on the other side of the mixing circuit unit 11 and the output end of the other transmission amplifier 18B. That is, the transmission signal transmitted from the dwelling unit terminal 3 connected to the transmission line 4B is taken into the receiving end 11B of the mixing circuit unit 11 from the second connection terminal 10B via the transmission line 4B.

  Here, in the communication system of the present embodiment, a conventionally known multi-carrier adaptive modulation method is employed as a transmission method for transmission signals. That is, in the control device 2, the dwelling unit terminal 3 of the first segment S1, and the relay device 1, based on the result of measuring the noise level for each subcarrier, the modulation method (multilevel modulation in digital modulation), the error correction code The communication mode such as the conversion rate and the carrier to be used is selected. Similarly, the communication mode such as the modulation method, the error correction coding rate, and the carrier to be used is selected based on the result of measuring the noise level for each subcarrier in the relay device 1 and the dwelling unit 3 in the second segment S2. Is done. By adopting the multicarrier adaptive modulation method in this way, even when the transmission loss deviation within the communication band is large or when the S / N ratio varies greatly depending on the frequency, such as when narrow band noise is mixed, A decrease in communication quality can be suppressed.

  Here, in the relay apparatus 1 of the present embodiment, the two receiving terminals 11A, 10A, 10B are used in order to share the receiving circuit (the receiving amplifier 12, the AD converter 13, and the receiving processing unit 14). The reception path of the transmission signal captured from 11B is mixed by the mixing circuit unit 11 and output to the reception amplifier 12. However, when the transmission signal is mixed in the mixing circuit unit 11, the subcarrier used in the transmission signal of the first segment S1 and the subcarrier used in the transmission signal of the second segment S2 are not overlapped. If the communication mode is selected, transmission signals can be simultaneously transmitted and received from the connection terminals 10A and 10B while avoiding a collision. The mixing circuit unit 11 is provided with a switch 11C that opens and closes the receiving path connected to the receiving end 11A, and the mixing circuit unit 11 starts mixing from the first connection terminal 10A only when the switch 11C is on. A transmission signal can be taken into the circuit unit 11.

  A circuit configuration example of the mixing circuit unit 11 is shown in FIG. For example, as shown in FIG. 2A, the mixing circuit unit 11 is amplified by two amplification circuits AP1 and AP2 that amplify transmission signals received by the reception terminals 11A and 11B, and the amplification circuits AP1 and AP2. And a mixing amplifier circuit AP3 having a transmission signal as an input. However, the reception amplifier 12 may be substituted for the mixing amplifier circuit AP3. As shown in FIG. 2B, the amplifier circuits AP1 and AP2 are composed of a grounded base amplifier circuit of an npn-type bipolar transistor TR, and a collector terminal (output terminal) of each bipolar transistor TR is composed of an emitter follower circuit. The amplifier circuit AP3 (or the receiving amplifier 12) is connected to the input terminal. By adopting such a circuit configuration, it is possible to prevent transmission signal leakage between the receiving end 11A and the receiving end 11B. The amplifier circuit AP1 connected to the receiving end 11A operates when the bias signal supplied to the base of the bipolar transistor TR is at a high level, and stops when the bias signal is at a low level. That is, it is possible to prevent transmission signal leakage when the amplifier circuit AP1 also serves as the switch 11C and the switch 11C is off (the amplifier circuit AP1 is stopped).

  The transmission signal mixed by the mixing circuit unit 11 and amplified by the receiving amplifier 12 is converted into a digital signal (baseband signal) for each subcarrier in the AD converter 13. The reception processing unit 14 decodes data (packets) from the digital signal converted by the AD converter 13.

  The relay processing unit 15 determines that the relay is unnecessary if the destination address of the packet decoded by the reception processing unit 14 is the address of the dwelling unit terminal 3 of the first segment S1, and determines that the destination address of the dwelling unit 3 of the second segment S2 If it is an address, it is determined that relay is necessary, and the packet is output to the transmission processing unit 16 only when it is determined that relay is necessary.

  The transmission processing unit 16 encodes the packet output from the relay processing unit 15 into a digital signal (baseband signal) for each subcarrier, modulates (orthogonal frequency multiplex modulation), and outputs the digital signal to the DA converter 17. The DA converter 17 converts the digital signal output from the transmission processing unit 16 into an analog transmission signal and outputs the analog transmission signal to the transmission amplifiers 18A and 18B. That is, the relayed transmission signal is amplified by the transmission amplifiers 18A and 18B, and is always sent to the transmission lines 4A and 4B simultaneously from both the first connection terminal 10A and the second connection terminal 10B.

  Next, an isolation performance inspection method that is the gist of the present invention will be described with reference to the sequence diagram of FIG. In the present embodiment, the relay processing unit 15 of the relay device 1 corresponds to an inspection unit. The relay processing unit 15 performs isolation performance inspection (hereinafter simply referred to as inspection) at the time of start-up or recovery from power reset.

  When the relay processing unit 15 starts the inspection, it turns off the switch 11C of the mixing circuit unit 11 to shut off (off) one of the reception paths, and then stores the packet (inspection request packet) in which the address of the control device 2 is stored in the destination address field. ) And output to the transmission processing unit 16. The inspection request packet is converted into a transmission signal by the transmission processing unit 16 and the DA converter 17, and sent to the transmission lines 4A and 4B from the first connection terminal 10A and the second connection terminal 10B via the transmission amplifiers 18A and 18B. The Further, the relay processing unit 15 starts counting the inspection packet waiting time from the time when the inspection request packet is output.

  On the other hand, the control device 2 that has received the inspection request packet converts the packet (inspection packet) in which the address of the relay device 1 is stored in the destination address field into a transmission signal and sends it to the transmission line 4A.

  The transmission signal (inspection packet) sent from the control device 2 to the transmission line 4A reaches the first connection terminal 10A of the relay device 1, but the switch 11C of the mixing circuit unit 11 is turned off and the reception route is blocked. Therefore, the relay processing unit 15 cannot receive (receive) the inspection packet. However, if the isolation performance is degraded, the transmission signal that has reached the first connection terminal 10A wraps around the second connection terminal 10B and is taken into the mixing circuit unit 11, and finally the inspection packet is relayed. It will be received by the unit 15.

  The relay processing unit 15 determines that there is an abnormality if an inspection packet is received while the inspection packet waiting time is being counted, that is, the isolation performance is degraded. On the other hand, if the inspection packet is not received during the inspection packet waiting time count, the relay processing unit 15 determines that there is no abnormality, that is, sufficient isolation performance is ensured. However, it is desirable to repeat the above-described inspection a plurality of times as shown in FIG. In this case, it is preferable that the relay processing unit 15 determines that there is no abnormality unless the inspection packet is received, and determines the level of isolation performance according to the number of receptions when the inspection packet is received even once.

  The relay processing unit 15 turns on the switch 11C of the mixing circuit unit 11 to end the inspection, and then transmits a packet (inspection result notification packet) in which the inspection result is stored in the data field to the control device 2. That is, in the present embodiment, the relay processing unit 15 serves as an inspection unit and a notification unit.

  On the other hand, when the control device 2 receives the inspection result notification packet, the control device 2 displays the inspection result notified by the packet on the display means (for example, a liquid crystal display, a light emitting diode, etc.), so Inform. Therefore, when the inspection result has an abnormality, it can be expected that a procedure for ensuring sufficient isolation performance (for example, reworking of the wiring work) is performed by the installer or the administrator.

  As described above, the relay device 1 according to the present embodiment includes the inspection unit that inspects the isolation performance between the connection terminals 10A and 10B and the notification unit that notifies the inspection result of the inspection unit. It is possible to prevent the transmission signal from being deteriorated due to the decrease in the transmission rate. Moreover, since the relay processing unit 15 inspects based on whether or not the inspection packet returned from the control device 2 is received, there is no need for the installer or administrator to perform any operation on the control device 2, and the inspection work Simplification can be achieved.

  By the way, there is a high possibility that a packet (transmission signal) is transmitted between the control device 2 and each dwelling unit 3 especially immediately after the system is started or immediately after the power reset. Therefore, there is a possibility that the inspection request packet and the packet collide and the inspection fails, or the inspection is started after the transmission of the packet is completed, so that it takes a long time to complete the inspection.

  Therefore, as shown in the sequence diagram of FIG. 4, immediately after the system is started or immediately after the power reset, the relay processing unit 15 sends a transmission request (RTS) packet (transmission signal) to the transmission lines 4A and 4B. It is preferable. That is, the control device 2 and the dwelling unit terminal 3 that have received the transmission request packet do not transmit a transmission signal until a predetermined time has elapsed after returning a ready (CTS) packet to the relay device 1. If the relay processing unit 15 receives the ready packet and then transmits the inspection request packet to start the inspection, the time required to complete the inspection can be shortened while avoiding packet collision.

  By the way, there is a case where it is desired to perform an inspection at an arbitrary timing other than at the time of starting the system or returning from the power reset. Therefore, as shown in the sequence diagram of FIG. 5, when the inspection start request packet is transmitted from the lobby interphone 5 and the relay processing unit 15 receives the inspection request start packet from the lobby interphone 5 via the control device 2. An inspection may be started.

  For example, when a special number different from any dwelling unit number is operated with the ten key switch, an inspection start request packet is transmitted from the lobby intercom 5 to the control device 2. The control device 2 transfers the inspection start request packet received from the lobby intercom 5 to the relay device 1. Upon receiving the inspection start request packet, the relay processing unit 15 transmits a transmission request (RTS) packet as shown in FIG. 5, and after receiving the ready packet, transmits the inspection request packet to start the inspection. That's fine. In this case, it is preferable that the inspection result transmitted from the relay device 1 is transferred to the lobby interphone 5 via the control device 2 and displayed on the lobby interphone 5.

  In the above description, the control device 2 returns the inspection packet. However, any dwelling unit 3 may return the inspection packet. Further, the reception path provided with the switch 11C may be either of the two reception paths, or both of the two reception paths. Further, if the management room device is installed in the management room of the apartment house and is connected to the control device 2, a packet of an inspection start request may be transmitted from the management room device instead of the lobby intercom 5.

1 relay device 2 control device 3 dwelling unit terminal
10A first connection terminal
10B Second connection terminal
12 Receiving amplifier (relay means)
13 AD converter (relay means)
14 Reception processing section (relay means)
15 Relay processing section (relay means, inspection means, notification means)
16 Transmission processor (relay means)
17 DA converter (relay means)
18A, 18B Transmitting amplifier (relay means)

Claims (3)

Two connection terminals each connected to a different transmission line and a transmission signal transmitted to the transmission line are received from the connection terminal, and the received transmission signal is relayed and transmitted from the connection terminal. Relay means, inspection means for inspecting isolation performance between the two connection terminals, reception path blocking means for blocking a reception path from one of the connection terminals to the relay means, and inspection of the inspection means An informing means for informing a result, wherein the relay means serves as both a transmission processing section for transmitting transmission signals to the plurality of transmission paths and a reception processing section for receiving transmission signals, and the inspection means. , said in a state where the receive path blocking means is blocking the receive path, it transmits a transmission signal for the test than the one connecting terminal which receives the route is blocked request, the search Relay transmission signal returned for the transmission signal for request, and performs inspection of isolation performance based on whether the received at one of the connection terminals different from the other of the connecting terminal apparatus. 2. A communication system comprising: the relay device according to claim 1; and a plurality of communication terminals respectively connected to the two connection terminals provided in the relay device via the transmission path, wherein the inspection means transmits the inspection request transmission. Before transmitting the signal, transmit the transmission signal of the transmission request from the one connection terminal, and when the communication terminal receives the transmission signal of the transmission request, returns the ready transmission signal to the relay device, The transmission means does not transmit the transmission signal until a predetermined time has elapsed after the transmission signal is returned, and the inspection means transmits the inspection request transmission signal after receiving the ready transmission signal. Communication system . 3. The communication according to claim 2 , wherein the inspection unit transmits the transmission signal of the transmission request when the relay unit receives the transmission signal of the inspection start request transmitted from any of the communication terminals. System .

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