JP2006180285A - Communication establishment method and communication system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a communication establishment method which prevents establishment of communication by a crosstalk signal between a station-side communication system and a terminal-side communication system not corresponding to each other originally. <P>SOLUTION: This communication establishment method is for establishing communication between a first communication system connected to one end of a communication line and a second communication system connected to the other end. The first communication system detects an input signal level from the second communication system (S1), and establishes communication with the second communication system (S4), based on the detected input signal level (S2, S3). <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a communication establishment method for establishing communication between a station-side communication device connected to one end of a communication line and a terminal-side communication device connected to the other end. ADSL (Asymmetric Digital Subscriber Line) that establishes communication between one or a plurality of terminal-side communication devices and a station-side communication device connected to the terminal-side communication device via a telephone line by one or a plurality of telephone lines made of a metal wire ) And VDSL (Very High Speed Digital Subscriber Line), etc.

  An xDSL transmission system that transmits a digital signal at high speed using a metal telephone line has become widespread. This is a technique for transmitting a digital signal having a frequency band exceeding 4 kHz using an existing metal telephone line, paying attention to the fact that the existing telephone band uses a frequency band of 4 kHz or less. This initialization signal transmission procedure is recommended as a handshake procedure in Non-Patent Document 3.

In the xDSL transmission method, there are mainly two types of initialization procedures for establishing communication. The first method is a method of first transmitting a signal for establishing communication from a terminal side communication device, The method is a method of transmitting a signal for establishing communication first from the station side communication device.
Japanese Patent No. 3078262 Japanese Patent No. 3319422 ITU-T (International Telecommunication Union Telecommunication Standardization Sector) Recommendation G. 992.1-G992.5 ITU-T (〃 〃) Recommendation G. 993.1 ITU-T (〃 〃) Recommendation G. 994.1

  Normally, a plurality of lines are bundled and accommodated in one cable, so that a crosstalk occurs in which a signal of one telephone line is transferred to another telephone line. When the crosstalk signal level is high, depending on the connection timing between the station side communication device and the terminal side communication device, the station side communication device and the terminal side communication device, which are not originally compatible, may establish communication at low speed due to crosstalk. There is a problem that there is.

  For example, as shown in FIG. 13, the station side communication device 5 is a collective station side communication device connected to a plurality of terminal side communication devices 1a, 2a,. Yes, when the initialization procedure for establishing communication is the above-described first method, for example, the terminal-side communication device 1a transmits the first signal for establishing communication. The signal transmitted from the terminal side communication device 1a reaches the port 1 connected by the telephone line 8 at the highest level, but a very small amount of signal reaches the ports 2 and 3 due to crosstalk.

  In this case, there is no problem if the port 1 responds earliest and communication is established with the terminal side communication device 1a as shown in FIG. 14, but it happens that the port 2 responds earliest and is shown in FIG. As described above, there is a risk of establishing communication with the terminal-side communication device 1a due to crosstalk. If communication between the port 2 and the terminal-side communication device 1a is established, the communication quality deteriorates because the port 2 and the terminal-side communication device 1a that are not originally compatible are connected. Further, there is a problem that the terminal side communication device 2a connected to the port 2 through the telephone line 8 cannot establish communication with any port.

In Patent Documents 1 and 2, “communication apparatus”, “multi-carrier transmission system,” which is a countermeasure against crosstalk noise from ISDN by changing the transmission speed by a dual bit map method corresponding to the burst period of ISDN. A “multi-carrier transmission method” is disclosed.
The present invention has been made in view of the above-described circumstances, and the first invention provides a communication establishment method that does not establish communication between a station-side communication apparatus and a terminal-side communication apparatus that are not originally supported by crosstalk. The purpose is to do.

  In the second invention, even when the station side communication device and the terminal side communication device that are not originally compatible establish communication due to crosstalk, the communication is disconnected between the station side communication device and the terminal side communication device to be established. An object of the present invention is to provide a communication establishment method that can reestablish communication correctly.

  It is an object of the third to sixth inventions to provide a communication apparatus in which a station-side communication apparatus and a terminal-side communication apparatus that are not originally compatible do not establish communication due to crosstalk.

  In the seventh to eleventh inventions, even when a station-side communication apparatus and a terminal-side communication apparatus that are not originally compatible establish communication due to crosstalk, the station-side communication apparatus and the terminal-side communication to be disconnected and to establish communication An object of the present invention is to provide a communication device that can establish communication correctly with the device.

  A communication establishment method according to a first aspect of the present invention is a communication establishment method for establishing communication between a first communication device connected to one end of a communication line and a second communication device connected to the other end. The first communication device detects an input signal level from the second communication device, and establishes communication with the second communication device based on the detected input signal level.

  A communication establishment method according to a second invention is the communication establishment method for establishing communication between a first communication device connected to one end of a communication line and a second communication device connected to the other end. The first communication device sends a signal that causes noise to the second communication device when communication is not established with the second communication device or when communication is established. And

  According to a third aspect of the present invention, there is provided a communication apparatus that is connected to one end of a communication line and performs communication via the communication line. An input signal level from another communication apparatus connected to the other end of the communication line is set. It comprises a detecting means for detecting, and a communication establishing means for establishing communication with the other communication device based on the input signal level detected by the detecting means.

  In the communication establishment method according to the first invention and the communication device according to the third invention, the communication is connected to one end of the communication line and communicates via the communication line. The detection means detects an input signal level from another communication device connected to the other end of the communication line, and the communication establishment means establishes communication with another communication device based on the input signal level detected by the detection means. .

  A communication device according to a fourth aspect of the present invention is a communication device that is connected to each one end of a plurality of communication lines and communicates with each other communication device connected to each other end of the plurality of communication lines. A plurality of detection means for detecting the input signal level from the communication device, a means for comparing the input signal level detected by the detection means and selecting another communication device having the maximum input signal level, and the means selected And a means for establishing communication with the other communication device.

  In the communication device according to the fourth aspect of the invention, the communication device is connected to each one end of the plurality of communication lines and communicates with each other communication device connected to each other end of the plurality of communication lines. A plurality of detecting means detects and selects an input signal level from each of the other communication devices, and a means for selecting compares the input signal level detected by the plurality of detecting means, and the other communication device having the maximum input signal level Select. The means for establishing communication establishes communication with another communication device selected by the means for selecting.

  The communication device according to a fifth aspect of the present invention further comprises means for determining whether or not the input signal level detected by the detecting means is greater than or equal to a predetermined value, wherein the communication establishing means has the input signal level at a predetermined value. It is characterized in that the communication is established when it is determined as described above.

  In the communication device according to the fifth aspect, the determining means determines whether or not the input signal level detected by the detecting means is equal to or higher than a predetermined value, and the communication establishing means is configured to determine whether the input signal level is a predetermined value. Communication is established when it is determined as above.

  A communication device according to a sixth aspect of the invention is characterized in that the detection means is configured to operate when an initial signal for establishing communication from another communication device is received.

  A communication device according to a seventh aspect of the present invention is a communication device that is connected to one end of a communication line and performs communication via the communication line, and has not established communication with another communication device connected to the other end of the communication line. In the case of communication or establishment of communication, noise signal transmission means for transmitting a signal that becomes noise to the other communication device is provided.

  In the communication device according to the seventh aspect of the invention, the communication device is connected to one end of the communication line and communicates through the communication line, and the noise signal sending means establishes communication with another communication device connected to the other end of the communication line. When there is no communication or when communication is established, a signal that causes noise is sent to another communication device.

  The communication apparatus according to an eighth aspect is characterized in that the noise signal transmission means is configured to transmit a signal that becomes noise every predetermined time.

  According to a ninth aspect of the present invention, there is provided a communication apparatus characterized in that the noise signal transmission means transmits a signal that causes noise immediately before requesting establishment of communication.

  A communication device according to a tenth aspect of the present invention includes a detection unit that detects an input signal level from the other communication device, and a unit that determines whether the input signal level detected by the detection unit is equal to or higher than a predetermined value. In addition, the noise signal transmitting means is configured to transmit a signal that becomes noise when the means determines that the input signal level is equal to or higher than a predetermined value.

  In the communication device according to the tenth invention, the detection means detects an input signal level from another communication device, and the determination means determines whether or not the input signal level detected by the detection means is a predetermined value or more. To do. The noise signal sending means sends a signal which becomes noise when the judging means judges that the input signal level is a predetermined value or more.

  The communication device according to an eleventh aspect is characterized in that the signal that becomes the noise is a signal that uses the entire frequency band or a partial frequency band of the signal to be transmitted to the other communication device.

  According to the communication establishment method according to the first aspect of the present invention, it is possible to realize a communication establishment method that does not establish communication between a station-side communication apparatus and a terminal-side communication apparatus that are not originally supported by crosstalk.

  According to the communication establishment method according to the second invention, even when a station-side communication apparatus and a terminal-side communication apparatus that are not originally compatible establish communication due to crosstalk, the station-side communication apparatus should disconnect this communication and establish communication. It is possible to realize a communication establishment method that can correctly establish communication with the terminal-side communication device.

  According to the communication devices according to the third, fifth, and sixth inventions, it is possible to realize a communication device in which communication is not established between a station-side communication device and a terminal-side communication device that are not originally supported by crosstalk.

  According to the communication device according to the fourth aspect of the present invention, communication is not erroneously established due to crosstalk with a plurality of other communication devices, and communication between the station side communication device and the terminal side communication device that are not originally supported is established due to crosstalk. Communication device that does not.

  According to the communication devices according to the seventh and eleventh aspects of the invention, even when communication between the station side communication device and the terminal side communication device that are not originally supported is established due to crosstalk, this communication is disconnected and the station side that should establish communication is established. It is possible to realize a communication device that can re-establish communication correctly between the communication device and the terminal-side communication device.

  According to the communication apparatus according to the eighth aspect of the present invention, even when a station-side communication apparatus and a terminal-side communication apparatus that are not originally compatible establish communication due to crosstalk, the station-side communication apparatus should disconnect this communication and establish communication. It is possible to realize a communication device that can re-establish communication correctly with the terminal-side communication device. Further, since a signal that becomes noise is transmitted every predetermined time, crosstalk due to noise is less likely to adversely affect other communication lines.

  According to the communication apparatus according to the ninth aspect of the present invention, even when a station-side communication apparatus and a terminal-side communication apparatus that are not originally compatible establish communication by crosstalk, the station-side communication apparatus should disconnect this communication and establish communication. It is possible to realize a communication device that can re-establish communication correctly with the terminal-side communication device. Further, since a signal that becomes noise is transmitted only immediately before requesting establishment of communication, crosstalk due to noise hardly affects other communication lines.

  According to the communication device of the tenth invention, even when a station-side communication device and a terminal-side communication device that are not originally compatible establish communication due to crosstalk, the station-side communication device should disconnect this communication and establish communication. It is possible to realize a communication device that can re-establish communication correctly with the terminal-side communication device. In addition, since a signal that becomes noise is transmitted only when there is a possibility that another communication apparatus has established communication due to crosstalk, the crosstalk due to noise hardly causes an adverse effect on other communication lines.

Hereinafter, the present invention will be specifically described with reference to the drawings showing embodiments thereof.
(Embodiment 1)
FIG. 1 is a block diagram showing the configuration of Embodiment 1 of a communication establishment method and communication apparatus according to the present invention. The station-side communication device 5a is a collective station-side communication device that is connected to a plurality of terminal-side communication devices through respective telephone lines 8. A CPU 18 controlled by a control signal from a communication control device (not shown) Control a plurality of ports 1, 2I,.

  Ports 1, 2,... Temporarily store input data transmitted via a network (not shown) such as the Internet or a LAN (Local Area Network) in order to adjust the transmission speed. The data once stored in the input buffer 11 is given to the modulator 12, and the modulator 12 performs modulation such as DMT (Discrete Multi Tone) for xDSL transmission on the given data. The data modulated by the modulator 12 is sent from the hybrid circuit 13 to the telephone line 8.

On the other hand, the data sent from the terminal side communication devices 1b, 2b,... Via the telephone line 8 by xDSL transmission is received by the hybrid circuit 13 and then demodulated by the demodulator 14 in order to adjust the transmission speed. The output buffer 15 temporarily stores it. Data once stored in the output buffer 15 is transmitted as output data to a predetermined address via a network such as the Internet or a LAN (not shown).
The level of the signal (input signal) sent from the hybrid circuit 13 to the demodulator 14 is detected by the sensor 16 and given to the transmission / reception control circuit 17. The transmission / reception control circuit 17 is controlled by the CPU 18 of the station side communication device 5a, and controls the input buffer 11, the modulator 12, the demodulator 14, and the output buffer 15 described above.

  The terminal side communication devices 1b, 2b,... Temporarily store input data from a terminal device such as a personal computer (not shown) in order to adjust the transmission speed. The data once stored in the input buffer 21 is given to the modulator 22, and the modulator 22 modulates the given data such as DMT for xDSL transmission. The data modulated by the modulator 22 is sent out from the hybrid circuit 23 to the telephone line 8.

On the other hand, the data sent from the ports 1 and 2 via the telephone line 8 by xDSL transmission is received by the hybrid circuit 23, demodulated by the demodulator 24, and the output buffer 25 is used to adjust the transmission speed. Remember once. Data once stored in the output buffer 25 is sent as output data to a terminal device such as a personal computer (not shown).
The level of the signal (input signal) sent from the hybrid circuit 23 to the demodulator 24 is detected by the sensor 26 and given to the transmission / reception control circuit 27. The transmission / reception control circuit 27 controls the input buffer 21, the modulator 22, the demodulator 24 and the output buffer 25 described above.
.. And the terminal side communication devices 1b, 2b,...

Hereinafter, the operation for establishing communication of the station side communication device 5a will be described with reference to the flowchart of FIG.
The CPU 18 of the station side communication device 5a reads the input signal level detected by each sensor 16 of each port 1, 2,..., Which has not established communication at regular time intervals via each transmission / reception control circuit 17 (S1), The read input signal levels are compared (S2).
Next, the CPU 18 selects the port having the maximum input signal level as a result of comparing the input signal levels (S2) (S3), and the terminal side communication device connected to the selected port via the telephone line 8 is selected. A response signal for establishing communication is output, and a procedure for establishing communication is executed (S4).

For example, as illustrated in FIG. 3, when the terminal-side communication device 1 b transmits the first signal for establishing communication, the signal transmitted by the terminal-side communication device 1 b is the port connected by the telephone line 8. Naturally, it reaches 1 at the highest level, but a small amount of signal reaches ports 2, 3, and 4 due to crosstalk. In FIG. 3, communication is established between the terminal-side communication device 4 b and the port 4 and communication is in progress.
However, since the CPU 18 of the station side communication device 5a outputs a response signal for establishing communication only to the port 1 having the highest input signal level among the ports 1, 2, and 3 in the reception waiting state, the terminal side Communication is established between the communication device 1b and the port 1, and communication establishment due to crosstalk does not occur.

(Embodiment 2)
FIG. 4 is a block diagram showing the configuration of Embodiment 2 of the communication establishment method and communication apparatus according to the present invention. The station-side communication device 7 is a counter-type station-side communication device that has a one-to-one correspondence with the terminal-side communication device 6, and input data transmitted via a network such as the Internet or a LAN (Local Area Network) not shown. Are temporarily stored in the input buffer 11 in order to adjust the transmission speed. The data once stored in the input buffer 11 is given to the modulator 12, and the modulator 12 modulates the given data such as DMT for xDSL transmission. The data modulated by the modulator 12 is sent from the hybrid circuit 13 to the telephone line 8.

On the other hand, the data sent from the terminal side communication device 6 via the telephone line 8 by xDSL transmission is received by the hybrid circuit 13, demodulated by the demodulator 14, and output buffer 15 for adjusting the transmission rate. Memorize once. Data once stored in the output buffer 15 is transmitted as output data to a predetermined address via a network such as the Internet or a LAN (not shown).
The level of the signal (input signal) sent from the hybrid circuit 13 to the demodulator 14 is detected by the sensor 16 and given to the transmission / reception control circuit 17 (CPU). The transmission / reception control circuit 17 is controlled by a control signal from a communication control device (not shown) and controls the input buffer 11, the modulator 12, the demodulator 14, and the output buffer 15 described above.

  In the terminal-side communication device 6, the input buffer 21 temporarily stores input data from a terminal device such as a personal computer (not shown) in order to adjust the transmission speed. The data once stored in the input buffer 21 is given to the modulator 22, and the modulator 22 modulates the given data such as DMT for xDSL transmission. The data modulated by the modulator 22 is sent from the hybrid circuit 23 to the telephone line 8.

On the other hand, data sent from the station side communication device 7 via the telephone line 8 by xDSL transmission is received by the hybrid circuit 23, demodulated by the demodulator 24, and output buffer 25 for adjusting the transmission rate. Memorize once. Data once stored in the output buffer 25 is sent as output data to a terminal device such as a personal computer (not shown).
The level of the signal (input signal) sent from the hybrid circuit 23 to the demodulator 24 is detected by the sensor 26 and given to the transmission / reception control circuit 27 (CPU). The transmission / reception control circuit 27 controls the input buffer 21, the modulator 22, the demodulator 24 and the output buffer 25 described above.

Below, the operation | movement about communication establishment of such a station side communication apparatus 7 is demonstrated, referring the flowchart of FIG.
When receiving the first signal for establishing communication, the transmission / reception control circuit 17 of the station side communication device 7 reads the level of the first signal for establishing communication detected by the sensor 16 (S10). It is determined whether or not the signal level is equal to or higher than a predetermined value (S11).
If the signal level is equal to or higher than a predetermined value (S11), the transmission / reception control circuit 17 outputs a response signal for establishing communication to the terminal-side communication device 6 and executes a communication establishment procedure (S12). If the input signal level is not higher than the predetermined value, the process returns.

The above-described operation is the operation of the station-side communication device 7 when a signal for establishing communication is first transmitted from the terminal-side communication device 6, but the signal for establishing communication is first received from the station-side communication device 7. The present invention can also be applied to the operation of the terminal side communication device 6 when transmitting.
Further, the case where the station-side communication apparatus is a counter-type station-side communication apparatus that supports only one port has been described, but the station-side communication apparatus 7 also includes a case where the station-side communication apparatus supports a plurality of ports. It can be applied to each port instead of.

  When the above-mentioned predetermined value is applied to the collective station side communication device, it is smaller than the uplink reception signal from the terminal side communication device located at the farthest position, and the signal from a certain terminal side communication device is crosstalked, and the station side communication It must be greater than the maximum value that can reach the device. For example, the uplink signal strength for each transmission speed and the maximum reception strength of the crosstalk signal from the terminal side communication apparatus 500 m ahead are as shown in FIG. 6, and in this case, the uplink signal strength is the maximum reception strength of the crosstalk signal. It is possible to set the signal intensity of a larger shaded portion to a predetermined value (a threshold value).

(Embodiment 3)
FIG. 7 is a flowchart showing the operation of the communication establishing method and communication apparatus according to Embodiment 3 of the present invention. The configuration of the third embodiment is the same as the block diagram (FIG. 1) showing the configuration of the communication establishment method and the communication device according to the present invention shown in the first embodiment, and a description thereof will be omitted. In FIG. 1, the station side communication device is a collective station side communication device. However, when the station side communication device is a counter type station side communication device (FIG. 4), the ports 1, 2,. It can be applied instead of the station side communication device 7.

Below, the operation | movement about communication establishment of the station side communication apparatus 5a (FIG. 1) is demonstrated, referring the flowchart of FIG.
Each transmission / reception control circuit 17 of the station side communication device 5a determines whether or not its own ports 1, 2,... Have established communication (S20), and establishes communication (including the execution of the procedure for establishment). If so, return. If communication has not been established (idle state), the time is counted by a built-in timer (S21), and it is determined whether or not the measured time has reached a predetermined time (S22), and if not, the process returns.

  Each transmission / reception control circuit 17 resets the timer (S23) if the measured time has reached the predetermined time (S23), and then to the terminal side communication devices 1b, 2b,. A signal that causes noise is transmitted for a predetermined time (S24). When a signal for noise is transmitted for a predetermined time and the first signal for establishing communication is received from the terminal side communication devices 1b, 2b,... (S25), the procedure for establishing communication is executed (S26). If the first signal is not received (S25), the process returns.

  For example, as illustrated in FIG. 9, when the terminal-side communication device 2 b establishes communication with the port 1 due to crosstalk, if a signal that causes noise is transmitted from the port 2, the terminal-side communication device 2 b has large noise Therefore, an error or out of synchronization occurs. Therefore, the disconnection logic works, the communication establishment state between the terminal side communication device 2b and the port 1 is canceled, and communication between the terminal side communication device 2b and the port 2 can be established.

Since the signal that becomes noise needs to generate an error and disconnect the communication establishment state, it must be a signal that overlaps the frequency band connected to the different port, and the entire frequency band or a part of the frequency band of the downstream signal The signal to be used (which may be an unmodulated signal) can be most easily realized.
Further, it is desirable that the intensity of a signal that causes noise is such an intensity that can disconnect a line connected to a different port, and that it does not cause a line disconnection or an error due to an adverse effect due to crosstalk on other lines. As a practical example, it is sufficient to send a signal of the same level as a downlink reception signal connected to a different port (set S / N = 1).

In this case, the transmission level of the signal that becomes noise is (downlink transmission signal) − (1 line crosstalk attenuation) + (line attenuation). The one-line crosstalk attenuation and the line attenuation are not a problem as long as they can be measured, but if they cannot be measured, the one holding past measurement data is used. When there is no past measurement data, it can be obtained by theoretical calculation based on numerical values described in TTC (JJ100.01) or the like.
If a signal that causes noise is frequently sent, it will adversely affect other lines due to crosstalk, so it is sent every predetermined time.

  The operation described above is the operation of the station side communication device 5a, but can also be applied to the operation of the terminal side communication devices 1b, 2b,. In this case, the signal that causes noise can be most easily realized as a signal (or an unmodulated signal) that uses the entire frequency band or a partial frequency band of the upstream signal.

(Embodiment 4)
FIG. 8 is a flowchart showing the operation of the communication establishment method and communication apparatus according to Embodiment 4 of the present invention. The configuration of the fourth embodiment is the same as the block diagram (FIG. 1) showing the configuration of the communication establishment method and the communication device according to the present invention shown in the first embodiment, and a description thereof will be omitted. In FIG. 1, the station side communication device is a collective station side communication device. However, when the station side communication device is a counter type station side communication device (FIG. 4), the ports 1, 2,. It can be applied instead of the station side communication device 7.

Hereinafter, the operation of the terminal side communication devices 1b, 2b,... (FIG. 1) regarding communication establishment will be described with reference to the flowchart of FIG.
When transmitting / receiving the first signal for establishing communication (S30), the transmission / reception control circuit 27 of the terminal side communication devices 1b, 2b,... First determines whether or not the parameter k is 0 (step S30). S31). If the parameter k is 0, a signal that causes noise is sent to the ports 1, 2,... Of the station side communication device 5a connected by the telephone line 8 for a predetermined time (S32). If the first signal for establishing communication is not sent (S30), the process returns.

Next, the transmission / reception control circuit 27 sends the first signal for establishing communication (S33), adds 1 to the parameter k (S34), and responds to the first signal from the ports 1, 2,. If there is no (S35), it is determined whether or not the parameter k is a predetermined value n (S36).
If the parameter k is the predetermined value n (S36), the transmission / reception control circuit 27 sets the parameter k to 0 (S37) and returns. If the parameter k is not the predetermined value n (S36), the process returns.

If there is no response signal (S35), the transmission / reception control circuit 27 returns to the operation of sending the first signal for establishing communication again (S30), and determines whether the parameter k is 0 or not. (S31). If the parameter k is not 0, the first signal for establishing communication is sent again (S33), and 1 is added to the parameter k (S34).
When there is a response signal to the first signal from the ports 1, 2,... (S35), the transmission / reception control circuit 27 sets the parameter k to 0 (S38), executes the communication establishment procedure (S39), and returns. To do.

  For example, as illustrated in FIG. 9, when the terminal-side communication device 2 b establishes communication with the port 1 due to crosstalk, if a signal that causes noise is transmitted from the terminal-side communication device 1 b, a large noise is generated in the port 1. Therefore, an error or out of synchronization occurs. Therefore, the disconnection logic works, the communication establishment state between the terminal-side communication device 2b and the port 1 is canceled, and communication between the terminal-side communication device 1b and the port 1 can be established.

The signal that becomes noise is the same as that described in the third embodiment regardless of the downlink signal and the uplink signal.
If a signal that causes noise is sent frequently, other lines will be adversely affected by crosstalk. Therefore, each time a handshake (first signal for establishing communication) is sent, the signal that becomes noise is sent. Send only once every n times, not send.

  The above-described operation is the operation of the station-side communication device 5a when a signal for establishing communication is first transmitted from the station-side communication device 5a. Can be applied to the operations of the terminal side communication devices 1b, 2b,.

(Embodiment 5)
FIG. 10 is a flowchart showing the operation of the fifth embodiment of the communication establishment method and communication apparatus according to the present invention. The configuration of the fifth embodiment is the same as the block diagram (FIG. 1) showing the configuration of the communication establishment method and the communication device according to the present invention shown in the first embodiment, and a description thereof will be omitted. In FIG. 1, the station side communication device is a collective station side communication device. However, when the station side communication device is a counter type station side communication device (FIG. 4), the ports 1, 2,. It can be applied instead of the station side communication device 7.

Below, the operation | movement about communication establishment of the station side communication apparatus 5a (FIG. 1) is demonstrated, referring the flowchart of FIG.
Each transmission / reception control circuit 17 of the station side communication device 5a determines whether or not its own ports 1, 2,... Have established communication (S40), and establishes communication (including during execution of the procedure for establishment). If so, return. If communication is not established (idle state), the input signal level detected by the sensor 16 is read (S41), and it is determined whether or not the read input signal level is equal to or higher than a predetermined value (S42).

If the input signal level is equal to or higher than a predetermined value (S42), the transmission / reception control circuit 17 sends a signal that becomes noise to the terminal side communication devices 1b, 2b,... Connected by the telephone line 8 for a predetermined time (S43). ). When a signal for noise is transmitted for a predetermined time and the first signal for establishing communication is received from the terminal-side communication devices 1b, 2b,... (S44), a communication establishment procedure is executed (S45).
If the input signal level is not equal to or higher than the predetermined value (S42), the transmission / reception control circuit 17 returns. If the first signal for establishing communication is not received (S44), the process returns.

  For example, as shown in FIG. 12, when the terminal side communication device 2b has established communication with the port 1 due to crosstalk, a high level signal is input to the port 2 even though communication has not been established. . In such a case, if a signal that causes noise is transmitted from the port 2, the terminal-side communication device 2 b becomes a large noise, and thus an error or out of synchronization occurs. Therefore, the disconnection logic works, the communication establishment state between the terminal side communication device 2b and the port 1 is canceled, and communication between the terminal side communication device 2b and the port 2 can be established.

The signal that becomes noise is the same as described in the third embodiment regardless of the downlink signal and the uplink signal.
The operation described above is the operation of the station side communication device 5a, but can also be applied to the operation of the terminal side communication devices 1b, 2b,. In this case, the signal that causes noise can be most easily realized as a signal (or an unmodulated signal) that uses the entire frequency band or a partial frequency band of the upstream signal.

(Embodiment 6)
FIG. 11 is a flowchart showing the operation of the sixth embodiment of the communication establishment method and communication apparatus according to the present invention. The configuration of the sixth embodiment is the same as the block diagram (FIG. 1) showing the configuration of the communication establishment method and the communication device according to the present invention shown in the first embodiment, and a description thereof will be omitted. In FIG. 1, the station side communication device is a collective station side communication device. However, when the station side communication device is a counter type station side communication device (FIG. 4), the ports 1, 2,. It can be applied instead of the station side communication device 7.

Hereinafter, the operation of the terminal side communication devices 1b, 2b,... (FIG. 1) regarding the communication establishment will be described with reference to the flowchart of FIG.
The transmission / reception control circuit 27 of the terminal side communication devices 1b, 2b,... Sends the first signal for establishing communication (S50), and if there is a response signal for the first signal from the ports 1, 2,. (S51), a communication establishment procedure is executed (S55), and the process returns.
If there is no response signal for the first signal from the ports 1, 2,... (S51), the transmission / reception control circuit 27 reads the input signal level detected by the sensor 26 (S52), and the read input signal level is a predetermined value. It is determined whether or not this is the case (S53).

  If the input signal level is equal to or higher than a predetermined value (S53), the transmission / reception control circuit 27 transmits a signal that causes noise to the ports 1, 2,... Of the station side communication device 5a connected by the telephone line 8 for a predetermined time. After that, the first signal for establishing communication is sent again (S50). If the input signal level is not greater than or equal to the predetermined value (S53), the first signal for establishing communication is sent again without sending a signal that causes noise (S50).

  For example, as shown in FIG. 12, when the terminal-side communication device 2b has established communication with the port 1 due to crosstalk, even if the terminal-side communication device 1b sends the first signal for establishing communication, the response No signal is returned, but a high level signal is input. In such a case, if a signal that causes noise is transmitted from the terminal-side communication device 1b, a large noise is generated in the port 1, so that an error or loss of synchronization occurs. Therefore, the disconnection logic works, the communication establishment state between the terminal-side communication device 2b and the port 1 is canceled, and communication between the terminal-side communication device 1b and the port 1 can be established.

The signal that becomes noise is the same as that described in the third embodiment regardless of the downlink signal and the uplink signal.
If a signal that causes noise is sent frequently, other lines will be adversely affected by crosstalk, so a handshake (first signal for establishing communication), which is the first stage of communication establishment, is sent and a response signal is returned. Only when the input signal level is equal to or higher than a predetermined value, a signal that causes noise is transmitted.

  The operation described above is the operation of the terminal side communication devices 1b, 2b,... When transmitting a signal for establishing communication from the terminal side communication devices 1b, 2b,. First, the present invention can be applied to the operation of the station side communication device 5a (ports 1, 2,...) When transmitting a signal for establishing communication.

It is a block diagram which shows the structure of embodiment of the communication establishment method and communication apparatus which concern on this invention. It is a flowchart which shows the operation | movement about communication establishment of the communication apparatus which concerns on this invention. It is explanatory drawing which shows operation | movement of the communication establishment method and communication apparatus which concern on this invention. It is a block diagram which shows the structure of embodiment of the communication establishment method and communication apparatus which concern on this invention. It is a flowchart which shows the operation | movement about communication establishment of the communication apparatus which concerns on this invention. It is a characteristic figure of the frequency-received signal strength for demonstrating the signal strength for distinguishing the first signal for communication establishment, and a crosstalk signal. It is a flowchart which shows operation | movement of embodiment of the communication establishment method and communication apparatus which concern on this invention. It is a flowchart which shows operation | movement of embodiment of the communication establishment method and communication apparatus which concern on this invention. It is explanatory drawing which shows operation | movement of the communication establishment method and communication apparatus which concern on this invention. It is a flowchart which shows operation | movement of embodiment of the communication establishment method and communication apparatus which concern on this invention. It is a flowchart which shows operation | movement of embodiment of the communication establishment method and communication apparatus which concern on this invention. It is explanatory drawing which shows operation | movement of the communication establishment method and communication apparatus which concern on this invention. It is explanatory drawing which shows operation | movement of the conventional communication establishment method and a communication apparatus. It is explanatory drawing which shows operation | movement of the conventional communication establishment method and a communication apparatus. It is explanatory drawing which shows operation | movement of the conventional communication establishment method and a communication apparatus.

Explanation of symbols

1, 2 Ports 1b, 2b, 6 Terminal side communication device 5a, 7 Station side communication device 8 Telephone line 11, 21 Input buffer 12, 22 Modulator 13, 23 Hybrid circuit 14, 24 Demodulator 15, 25 Output buffer 16, 26 Sensor 17, 27 Transmission / Reception Control Circuit 18 CPU

Claims (11)

In a communication establishment method for establishing communication between a first communication device connected to one end of a communication line and a second communication device connected to the other end,
The first communication device detects an input signal level from the second communication device, and establishes communication with the second communication device based on the detected input signal level. In a communication establishment method for establishing communication between a first communication device connected to one end of a communication line and a second communication device connected to the other end,
The first communication device sends a signal that causes noise to the second communication device when communication is not established with the second communication device or when communication is established. A method for establishing communication. In a communication device connected to one end of a communication line and performing communication via the communication line,
Detection means for detecting an input signal level from another communication device connected to the other end of the communication line, and communication establishment means for establishing communication with the other communication device based on the input signal level detected by the detection means A communication device comprising: In a communication device connected to each one end of a plurality of communication lines and communicating with each other communication device connected to each other end of the plurality of communication lines,
A plurality of detection means for detecting the input signal level from each of the other communication devices, a means for comparing the input signal level detected by the detection means and selecting another communication device having the maximum input signal level; A communication apparatus comprising: means for establishing communication with another communication apparatus selected by the means.   Means for determining whether or not the input signal level detected by the detection means is greater than or equal to a predetermined value; and when the means for establishing communication determines that the input signal level is greater than or equal to a predetermined value, The communication apparatus according to claim 3, wherein the communication apparatus is configured to establish communication.   The communication device according to any one of claims 3 to 5, wherein the detection unit is configured to operate when a first signal for establishing communication from another communication device is received. In a communication device connected to one end of a communication line and performing communication via the communication line,
A noise signal sending means for sending a signal that becomes noise to the other communication device when communication is not established with the other communication device connected to the other end of the communication line or when communication is established. A communication device.   8. The communication apparatus according to claim 7, wherein the noise signal sending means is configured to send a signal that becomes noise every predetermined time.   8. The communication apparatus according to claim 7, wherein the noise signal transmission means transmits a signal that causes noise immediately before requesting establishment of communication.   Detecting means for detecting an input signal level from the other communication device; and means for determining whether or not the input signal level detected by the detecting means is equal to or higher than a predetermined value. 8. The communication apparatus according to claim 7, wherein said noise signal sending means is configured to send a signal that becomes noise when it is determined that is equal to or greater than a predetermined value.   The communication device according to any one of claims 7 to 10, wherein the signal that becomes noise is a signal that uses a full frequency band or a partial frequency band of a signal to be transmitted to the other communication device.

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