JP4857778B2 - DSLAM and CPE for xDSL systems - Google Patents

Description

  The present invention relates to a DSLAM (intra-station multiplexer) and a CPE (customer premises equipment) that monitor and control user traffic in an xDSL communication system and maintain good communication quality.

An xDSL communication system that realizes high-speed data communication via an existing telephone line is widespread. In this system, the communication speed varies greatly depending on the line state of the xDSL subscriber line. Therefore, monitoring and control of the line state is a major technical problem, and many conventional techniques aiming to solve this problem have been disclosed (for example, see Patent Document 1). In such a technique, a monitoring unit is provided to check the state of occurrence of noise in the line, and the line state is continuously monitored.
Japanese Patent Application Laid-Open No. 2004-236094

  However, in the conventional technology, the monitoring unit constantly monitors the line state, but the occurrence of the malfunction is caused by a malfunction in the line condition such as an increase in noise due to the influence from the ISDN line, or It was difficult to execute accurate and quick line control because it was not possible to determine whether the failure was caused by a malfunction of the device such as a CPE (customer premises equipment) failure.

<Configuration 1>
The present invention is a DSLAM (intra-station multiplexing device) for an xDSL system, which is formed between a control signal flowing through a control channel formed between the DSLAM and the CPE (customer premises equipment), and between the DSLAM and the CPE. A quality detection unit that monitors the quality of the carrier data signal that flows through the user traffic, and operates at a predetermined time interval, transmits a predetermined control signal determined in advance to the control channel, and controls the control from the CPE device. A loop test execution unit that receives a response signal to the signal, and a device state determination unit that determines a device state of the CPE based on a quality monitoring result of the control signal by the quality detection unit while the loop test execution unit is in operation When the determination result of the device state determination unit is normal, the quality detection result of the carrier data signal by the quality detection unit Based to mainly characterized in that it comprises a line status determination section for determining line condition.
<Configuration 2>
The present invention is a CPE for an xDSL system, the quality of a control signal flowing through a control channel formed between the CPE and the DSLAM, and a carrier data signal flowing through user traffic formed between the CPE and the DSLAM A quality detection unit that monitors the quality of the loop, a loop test execution unit that operates at a predetermined time interval, transmits a predetermined control signal determined in advance to the control channel, and receives a response signal to the control signal from the DSLAM, When the loop test execution unit is in operation, the device state determination unit that determines the device state of the DSLAM based on the quality monitoring result of the control signal by the quality detection unit, and the determination result of the device state determination unit is normal DSLAM state, A line state determination unit for determining a line state based on the monitoring result of the carrier data signal by the quality detection unit, and a predetermined information device A LAN / I / F unit connected to the LAN transmission path, and a predetermined control signal is transmitted to the LAN transmission path at a predetermined time interval via the LAN / I / F unit. An autonomous diagnosis execution unit that accepts a response signal of the signal, determines whether or not the LAN transmission line is in a normal state, and generates a LAN abnormality notification if the determination result is an abnormal state; The main feature is that, when a predetermined control signal predetermined at predetermined time intervals is received from the described DSLAM, a LAN abnormality notification is included in the response signal of the control signal.

  At predetermined time intervals from DSLAM, a predetermined control signal determined in advance is transmitted to the control channel to execute a loop test for the CPE, and after confirming that the CPE device status is normal, the DSLAM and CPE Since the line state of the user traffic formed between them is determined, the determination result is accurate, and it is possible to appropriately and promptly cope with a line failure.

  In the present invention, since all the main components are formed only by changing the control program in the prior art, it can be implemented without adding hardware.

FIG. 1 is a block diagram of a communication system including DSLAM and CPE according to the present invention.
As shown in the figure, a communication system 300 including a DSLAM 200 and a CPE 100 according to the present invention is connected to a station side via a subscriber line 7 from an information device such as a PC (personal computer) 1 arranged on the subscriber side. A system that can access the Internet network 11 is formed. Further, a LAN (local area network) may be interposed between the CPE 100 and the PC 1.

The DSLAM 200 and CPE 100, which are the main part of the present invention, will be described in detail. Other parts will be described later as needed in the operation description.
FIG. 2 is a functional block diagram of a DSLAM according to the present invention.
This figure shows the purpose of the present invention, which is to monitor and control user traffic in an xDSL communication system, maintain a good communication quality, and enable an appropriate and quick response to a line failure. Primarily, it is a functional block diagram of DSLAM for explaining the configuration of the present invention.

  As shown in the figure, a DSLAM 200 according to the present invention includes an xDSL / I / F unit 201, a transmission / reception control unit 202, a quality detection unit 203, a signal detection unit 204, a device state determination unit 205, and a line state determination unit 206. A data storage unit 207, an initialization setting unit 208, a loop test execution unit 209, a CPU 210, a ROM 211, and a RAM 212.

  The xDSL / I / F unit 201 is an interface circuit that communicatively connects the DSLAM 200 to the downlink monitoring control channel 215, the downlink user traffic 216, the uplink monitoring control channel 217, and the uplink user traffic 218.

  The transmission / reception control unit 202 controls the xDSL / I / F unit 201 to connect the DSLAM 200 with the downlink monitoring control channel 215, the downlink user traffic 216, the uplink monitoring control channel 217, and the uplink user traffic 218. It is a part for transmitting / receiving a predetermined control signal and multiplexed signal between the two. This part is a part that represents a function that is activated and generated by the CPU 210 executing a predetermined control program stored in advance in the ROM 211 as a block.

  The quality detection unit 203 monitors the control signal or multiplexed signal received by the xDSL / I / F unit 201 based on the control of the transmission / reception control unit 202, and the quality state (for example, SNR, data rate, operation) of those signals This is a part for detecting the load factor and the like and sending it to the apparatus state determination unit 205 or the line state determination unit 206. Here, SNR represents Signal to Noise Reito.

  The signal detection unit 204 monitors the control signal or multiplexed signal received by the xDSL / I / F unit 201 based on the control of the transmission / reception control unit 202, and the ON / OFF state of the power supply of the CPE 100 (FIG. 1) to counter It is a part to confirm.

  Based on the control of the loop test execution unit 209, the apparatus state determination unit 205 acquires the quality state of the control signal from the quality detection unit 203 while the loop test execution unit 209 is in operation, and is stored in the data storage unit 207 in advance. This is a part for determining whether or not the opposing CPE 100 (FIG. 1) is operating normally. This part is a part that represents a function that is activated and generated by the CPU 210 executing a predetermined control program stored in advance in the ROM 211 as a block.

  The line state determination unit 206 receives the quality state of the control signal or multiplexed signal from the quality detection unit 203, compares it with the threshold value stored in advance in the data storage unit 207, and communicates with the opposing CPE 100 (FIG. 1). This is a part for determining whether or not the line state (for example, SNR, data rate, operating load factor, etc.) is normal. This part is a part that represents a function that is activated and generated by the CPU 210 executing a predetermined control program stored in advance in the ROM 211 as a block.

  The data storage unit 207 is a non-volatile memory that stores in advance thresholds used for predetermined determinations by the device state determination unit 205 and the line state determination unit 206 and data necessary for the determination. Further, it is a memory that stores predetermined data as a data history based on the control of the initialization setting unit 208.

  The initialization setting unit 208 determines that the line status between the DSLAM 200 and the CPE 100 (FIG. 1) that the line state determination unit 206 determines from the determination result of the line state determination unit 206 after the loop test is executed by the loop test execution unit 209. On the basis of the determination result that the communication is abnormal, the user traffic is stopped, and the communication mode, the frequency of the carrier wave, the data communication speed, and the like are reset. This part is a part that represents a function that is activated and generated by the CPU 210 executing a predetermined control program stored in advance in the ROM 211 as a block.

  The loop test execution unit 209 controls the xDSL / I / F unit 201 and the transmission / reception control unit 202, and transmits a predetermined control signal set in advance to the control channel at a predetermined time interval, from the CPE 100 (FIG. 1). This is a part for executing a loop test for receiving a response signal to the control signal. This part is a part that represents a function that is activated and generated by the CPU 210 executing a predetermined control program stored in advance in the ROM 211 as a block.

  The CPU 210 is a microprocessor that controls the entire DSLAM 200 by executing a predetermined control program stored in advance in the ROM 211. In particular, in the present embodiment, a predetermined control program stored in advance in the ROM 211 is executed, and the transmission / reception control unit 202, device state determination unit 205, line state determination unit 206, initialization setting unit 208, and loop test execution are executed. This is a part for starting and generating the unit 209.

  The ROM 211 is executed by the CPU 210 to activate the control program for controlling the entire DSLAM 200, the transmission / reception control unit 202, the device state determination unit 205, the device state determination unit 205, the initialization setting unit 208, and the loop test execution unit 209. It is a read-only memory that stores a control program to be generated in advance. The RAM 212 is a random access memory that forms a calculation area required by the CPU 210 during execution of calculation processing. The common bus 213 is a data line that communicates and connects the above portions.

FIG. 3 is a functional block diagram of the CPE according to the first embodiment.
This figure shows the purpose of the present invention, which is to monitor and control user traffic in an xDSL communication system, maintain a good communication quality, and enable an appropriate and quick response to a line failure. FIG. 2 is a functional block diagram of a CPE mainly for explaining the configuration of the first embodiment.

  As shown in the figure, the CPE 100 according to this embodiment includes an xDSL / I / F unit 101, a transmission / reception control unit 102, a quality detection unit 103, a signal detection unit 104, a device state determination unit 105, and a line state determination unit. 106, initialization setting unit 107, loop test execution unit 108, data storage unit 109, CPU 110, ROM 111, RAM 112, and common bus 113.

  The xDSL / I / F unit 101 is an interface circuit that communicatively connects the CPE 100 to the downlink monitoring control channel 215, the downlink user traffic 216, the uplink monitoring control channel 217, and the uplink user traffic 218.

  The transmission / reception control unit 102 controls the xDSL / I / F unit 101 to connect the CPE 100 with the downlink monitoring control channel 215, the downlink user traffic 216, the uplink monitoring control channel 217, and the uplink user traffic 218. It is a part for transmitting / receiving a predetermined control signal and multiplexed signal between the two. This part is a part that represents a function that is activated and generated by the CPU 110 executing a predetermined control program stored in advance in the ROM 111 as a block.

  The quality detection unit 103 indicates the quality state (for example, SNR, data rate, operating load factor, etc.) of the control signal or multiplexed signal received by the xDSL / I / F unit 101 based on the control of the transmission / reception control unit 102. This is a part that is detected and sent to the apparatus state determination unit 105 or the line state determination unit 106.

  The signal detection unit 104 monitors the control signal or multiplexed signal received by the xDSL / I / F unit 101 based on the control of the transmission / reception control unit 102, and powers on / off the DSLAM 200 (FIG. 1). It is a part to confirm.

  The apparatus state determination unit 105 acquires the quality state of the control signal from the quality detection unit 103 during the operation of the loop test execution unit 108 based on the control of the loop test execution unit 108 and is stored in the data storage unit 109 in advance. This is a part for determining whether or not the DSLAM 200 (FIG. 1) to be opposed is operating normally. This part is a part that represents a function that is activated and generated by the CPU 110 executing a predetermined control program stored in advance in the ROM 111 as a block.

  The line state determination unit 106 acquires the quality state of the control signal or the multiplexed signal from the quality detection unit 103, compares it with a threshold value stored in advance in the data storage unit 109, and compares it with the opposing DSLAM 200 (FIG. 1). This is a part for determining whether or not the line state (for example, SNR, data rate, operating load factor, etc.) is normal. This part is a part that represents a function that is activated and generated by the CPU 110 executing a predetermined control program stored in advance in the ROM 111 as a block.

  The initialization setting unit 107 determines whether the determination result of the line state determination unit 106 is the line state with the opposing DSLAM 200 (FIG. 1) when the operation of the CPE 100 is started or after the loop test execution by the loop test execution unit 108. Based on the judgment result that the SNR, data rate, working load factor, etc. are abnormal, the user traffic is stopped and the communication mode, carrier frequency, data communication rate, etc. are reset. is there. This part is a part that represents a function that is activated and generated by the CPU 110 executing a predetermined control program stored in advance in the ROM 111 as a block.

  The loop test execution unit 108 controls the xDSL / I / F unit 101 and the transmission / reception control unit 102 to transmit a predetermined control signal set in advance at predetermined time intervals to the control channel, and from the DSLAM 200 (FIG. 1). This is a part for executing a loop test for receiving a response signal to the control signal. This part is a part that represents a function that is activated and generated by the CPU 110 executing a predetermined control program stored in advance in the ROM 111 as a block.

  The data storage unit 109 is a non-volatile memory that stores in advance thresholds used by the device state determination unit 105 and the line state determination unit 106 for predetermined determination and data necessary for the determination. Further, it is a memory that stores predetermined data as a data history based on the control of the initialization setting unit 107.

  The CPU 110 is a microprocessor that controls the entire CPE 100 by executing a predetermined control program stored in advance in the ROM 111. In particular, in this embodiment, a predetermined control program stored in advance in the ROM 111 is executed, and the transmission / reception control unit 102, the device state determination unit 105, the line state determination unit 106, the initialization setting unit 107, and the loop test execution unit. 108 is a part for starting and generating 108.

  The ROM 111 executes and generates a control program executed by the CPU 110 to control the entire CPE 100, the transmission / reception control unit 102, the device state determination unit 105, the line state determination unit 106, the initialization setting unit 107, and the loop test execution unit 108. This is a read-only memory that stores in advance a control program to be executed. The RAM 112 is a random access memory that forms a calculation area required by the CPU 110 during execution of calculation processing. The common bus 113 is a data line that communicates and connects the above portions.

Next, returning to FIG. 1, the overall operation of the system will be described.
On the subscriber side, the data signal transmitted from the PC 1 is converted into a carrier data signal obtained by modulating a predetermined carrier wave with the data signal via the CPE 100 and transmitted to the subscriber-side splitter 6. On the other hand, a call signal transmitted from the telephone 4 is transmitted to a subscriber-side splitter 6 via a PBX (private branch exchange) 5. The carrier signal and the call signal are multiplexed by the subscriber side splitter 6 and transmitted to the station side splitter 8 via the subscriber line 7.

  Here, the subscriber-side splitter 6 is arranged on the subscriber side, accepts a carrier data signal (frequency band higher than the call signal band) from the CPE 100, and accepts a call signal (an analog signal of usually several KHz or less) from the PBX 5. And is sent to the station-side splitter 8 via the subscriber line 7. Further, a signal obtained by multiplexing the carrier data signal and the call signal is received from the station side splitter 8 via the subscriber line 7 and separated into the carrier data signal and the call signal, and the carrier data signal is sent to the CPE 100. Are transmitted to the PBX 5 respectively.

  When the station-side splitter 8 receives the multiplexed signal of the carrier data signal and the call signal via the subscriber line 7, the station-side splitter 8 separates the carrier data signal and the call signal into the carrier data signal and sends the carrier data signal to the DSLAM 200. Are sent to the telephone exchange 10, respectively. The DSLAM 200 converts the carrier data signals of multiple channels to be collected into data signals, concentrates them, and transmits them to the Internet network 11. On the other hand, the telephone exchange 10 collects the collected multi-channel call signals and transmits them to the subscriber telephone network 12.

  Here, the station-side splitter 8 accepts a signal obtained by multiplexing the carrier data signal and the call signal from the subscriber-side splitter 6 via the subscriber line 7 on the station side, and converts the signal into the carrier data signal and the call signal. In this part, the carrier data signal is sent to the DSLAM 200 and the call signal is sent to the telephone exchange 10. Further, it is a part that accepts a carrier data signal from the DSLAM 200, accepts a call signal from the telephone exchange 10, multiplexes it, and sends it to the subscriber-side splitter 6 via the subscriber line 7.

  A data signal transmitted from the Internet network 11 to the PC 1 and a call signal transmitted from the subscriber telephone network 12 to the telephone 4 travel in the opposite direction to the above description through the same signal path as described above. The description is omitted because only the reverse process is performed.

  Next, returning to FIG. 2, the operation for monitoring and controlling the system from the DSLAM 200 side will be described in five steps.

Step S1-1
When the DSLAM 200 starts operation, the initialization setting unit 208 controls the xDSL / I / F unit 201, the transmission / reception control unit 202, the quality detection unit 203, and the signal detection unit 204 to execute initialization setting. In the initialization setting, the mode setting is first executed, for example, the annex C mode is set. Next, training is executed, and a predetermined carrier frequency and data communication speed are set. The mode, carrier frequency, data communication speed, and the like set here are stored in the data storage unit 207 as a history by the initialization setting unit 208. Data communication is started after initialization.

Step S1-2
The loop test execution unit 209 controls the xDSL / I / F unit 201 and the transmission / reception control unit 202, and transmits predetermined control signals stored in the data storage unit 207 to the control channel at predetermined time intervals. Then, a loop test for receiving a response signal to the control signal from the CPE 100 (FIG. 1) is executed.

Step S1-3
The device state determination unit 205 acquires predetermined monitoring data from a response signal that flows through the uplink monitoring control channel 217 via the xDSL / I / F unit 201, the transmission / reception control unit 202, the quality detection unit 203, and the signal detection unit 204. To do. Upon obtaining the monitoring data, the device state determination unit 205 obtains a threshold value when the preset device state is normal from the data storage unit 207 and compares it. If the monitoring result satisfies the threshold, it is determined that the device state is normal, a device state normality notification is sent to the line state determination unit 206, and the process proceeds to step S1-4. If the monitoring result does not satisfy the threshold value, it is determined that the apparatus state is abnormal, a predetermined alarm is issued from an alarm means (not shown), the administrator is notified, and the subsequent processing is stopped.

Step S1-4
Upon receiving the device state normality notification from the device state determining unit 205, the line state determining unit 206 receives an uplink user via the xDSL / I / F unit 201, the transmission / reception control unit 202, the quality detecting unit 203, and the signal detecting unit 204. Obtain predetermined monitoring data from the carrier data signal flowing in the traffic 218. When the monitoring data is accepted, a threshold value when the preset line state is normal is acquired from the data storage unit 207 and compared. If the monitoring result satisfies the threshold value, it is determined that the line state is normal, and data communication is continued until the next loop test. If the monitoring result does not satisfy the threshold value, it is determined that the line state is abnormal, and a line state abnormality notification is sent to the initialization setting unit 208.

Step S1-5
When the initialization setting unit 208 receives the line state abnormality notification from the line state determination unit 206, the initialization setting unit 208 stops the user traffic and executes the initialization setting again in the same procedure as in step S1-1. Thereafter, steps S1-1 to S1-4 are repeatedly executed.

The conditions under which the line state determination unit 206 determines that the line state is abnormal in step S1-4 are as follows.
(1) The data communication speed in user traffic is measured when the field is opened, and the measured value is stored in the data storage unit 207 in advance as a reference data communication speed. If the data communication speed acquired in step S1-4 is lower than the reference data communication speed by a predetermined rate, and the reduced state continues for a predetermined time or more, it is determined that the line state is abnormal. Here, the predetermined ratio and the predetermined time are determined in advance and stored in the data storage unit 207.
(2) When the operating load factor of the DSLAM exceeds a predetermined value, it is determined that the line state is abnormal. This predetermined value is determined in advance and stored in the data storage unit 207.
(3) In addition, it is determined that the line condition is abnormal when a specific monitoring item that is determined in advance according to the circumstances of each system exceeds a specified value. This specified value is determined in advance and stored in the data storage unit 207.

  Normally, monitoring and controlling from the DSLAM 200 side as described above is common, but sometimes the network may be monitored and controlled from the CPE 100 side, so returning to FIG. 3, the network is monitored from the CPE 100 side. The operation to be monitored will be described in five steps.

Step S2-1
When the CPE 100 starts operation, the initialization setting unit 107 controls the xDSL / I / F unit 101, the transmission / reception control unit 102, the quality detection unit 103, and the signal detection unit 104 to execute initialization setting. In the initialization setting, the mode setting is first executed, for example, the annex C mode is set. Next, training is executed, and a predetermined carrier frequency and data communication speed are set. The mode, carrier frequency, data communication speed, and the like set here are stored as a history in the data storage unit 109 by the initialization setting unit 107. Data communication is started after initialization.

Step S2-2
The loop test execution unit 108 controls the xDSL / I / F unit 101 and the transmission / reception control unit 102 and transmits a predetermined control signal stored in the data storage unit 109 to the control channel at predetermined time intervals. , Execute a loop test to receive a response signal to the control signal from the DSLAM 200 (FIG. 1).

Step S2-3
The device state determination unit 105 acquires predetermined monitoring data from a response signal flowing through the downlink monitoring control channel 215 via the xDSL / I / F unit 101, the transmission / reception control unit 102, the quality detection unit 103, and the signal detection unit 104. To do. When the monitoring data is acquired, a threshold value when the preset device state is normal is acquired from the data storage unit 109 and compared. If the monitoring result satisfies the threshold value, it is determined that the device state is normal, a device state normality notification is sent to the line state determination unit 106, and the process proceeds to step S2-4. If the monitoring result does not satisfy the threshold value, it is determined that the apparatus state is abnormal, a predetermined alarm is issued from an alarm means (not shown), the administrator is notified, and the subsequent processing is stopped.

Step S2-4
Upon receiving the device state normality notification from the device state determining unit 105, the line state determining unit 106 receives the downlink user via the xDSL / I / F unit 101, the transmission / reception control unit 102, the quality detecting unit 103, and the signal detecting unit 104. Obtain predetermined monitoring data from the data signal flowing in the traffic 216. When the monitoring data is accepted, a threshold value when the preset line state is normal is acquired from the data storage unit 109 and compared. If the monitoring result satisfies the threshold value, it is determined that the line state is normal, and data communication is continued until the next loop test. If the monitoring result does not satisfy the threshold value, it is determined that the line state is abnormal, and a line state abnormality notification is sent to the initialization setting unit 107.

Step S2-5
When the initialization setting unit 107 receives the line state abnormality notification from the line state determination unit 106, the initialization setting unit 107 stops the user traffic and performs the initialization setting again in the same procedure as in step S2-1. Thereafter, steps S2-1 to S2-4 are repeatedly executed.

The conditions under which the line state determination unit 106 determines that the line state is abnormal in step S2-4 are as follows.
(1) The data communication speed in the user traffic is measured when the field is opened, and the measured value is stored in the data storage unit 109 in advance as a reference data communication speed. If the data communication speed acquired in step S2-4 is lower than the reference data communication speed by a predetermined rate and the reduced state continues for a predetermined time or more, it is determined that the line state is abnormal. Here, the predetermined ratio and the predetermined time are determined in advance and stored in the data storage unit 109.
(2) For other specific monitoring items determined in advance according to the circumstances of each system, it is determined that the line condition is abnormal when the specified value is exceeded. This specified value is determined in advance and stored in the data storage unit 109.

  As described above, according to this embodiment, the DSLAM 200 (FIG. 1) transmits a predetermined control signal stored in the data storage unit 207 (FIG. 2) to the control channel at a predetermined time interval. A loop test is performed on the CPE 100 (FIG. 1), and after confirming that the device state of the CPE 100 (FIG. 1) is normal, the user traffic formed between the DSLAM 200 (FIG. 1) and the CPE 100 (FIG. 1) Since the line state is determined, the determination result is accurate, and an effect that an appropriate and quick response to the line failure can be obtained is obtained.

  In the present embodiment, it is assumed that a LAN is connected to the CPE, and the purpose is to prevent the DSLAM from making a misjudgment when a failure occurs in the LAN. In order to achieve this object, the CPE of Example 2 is configured as follows.

FIG. 4 is a functional block diagram of the CPE according to the second embodiment.
This figure shows the purpose of the present invention, which is to monitor and control user traffic in an xDSL communication system, maintain a good communication quality, and enable an appropriate and quick response to a line failure. It is a functional block diagram of CPE mainly for explaining the configuration of the second embodiment.

  As shown in the figure, the CPE 300 according to this embodiment includes an xDSL / I / F unit 101, a transmission / reception control unit 102, a quality detection unit 103, a signal detection unit 104, a device state determination unit 105, and a line state determination unit. 106, initialization setting unit 107, loop test execution unit 108, data storage unit 109, LAN / I / F unit 131, LAN transmission / reception control unit 132, autonomous diagnosis execution unit 133, CPU 134, ROM 135 A RAM 112 and a common bus 113. Only the parts different from the first embodiment will be described below. The same parts as those in the first embodiment are denoted by the same reference numerals as those in the first embodiment, and the description thereof is omitted.

  The LAN / I / F unit 131 is an interface circuit that communicatively connects the CPE 300 and the LAN transmission path 301.

  The LAN transmission / reception control unit 132 is a part that controls the LAN / I / F unit 131 to transmit and receive predetermined control signals and data signals between the CPE 300 and the LAN transmission path 301. This part is a part that represents a function that is activated and generated when the CPU 134 executes a predetermined control program stored in advance in the ROM 135 as a block.

  The autonomous diagnosis execution unit 133 transmits a predetermined control signal to the LAN transmission path 301 via the LAN transmission / reception control unit 132 and the LAN / I / F unit 131 at predetermined time intervals. The response signal is accepted, compared with a predetermined threshold value, and if the response signal does not satisfy the threshold value, a LAN state abnormality notification is generated, and the response signal of the periodic loop test described in the first embodiment It is a part which transmits to DSLAM200 (FIG. 1). This part is a part that represents a function that is activated and generated when the CPU 134 executes a predetermined control program stored in advance in the ROM 135 as a block. Here, the predetermined time interval, the predetermined control signal, and the predetermined threshold value are stored in the data storage unit 109 in advance.

  The CPU 134 is a microprocessor that controls the entire CPE 300 by executing a predetermined control program stored in advance in the ROM 135. In particular, in this embodiment, in addition to the control in the first embodiment, a predetermined control program stored in advance in the ROM 135 is executed, and the LAN transmission / reception control section 132 and the autonomous diagnosis execution section 133 are activated. -The part to be generated.

  The ROM 135 is executed by the CPU 134 and added to the control program for controlling the entire CPE 300 and the control program stored in the above embodiment, and the CPU 134 is executed to activate the LAN transmission / reception control unit 132 and the autonomous diagnosis execution unit 133. It is a read-only memory that stores a control program to be generated.

  As described above, in the present embodiment, the LAN is connected to the CPE by adding the LAN / I / F unit 131, the LAN transmission / reception control unit 132, and the autonomous diagnosis execution unit 133 to the configuration of the first embodiment. Even if a failure occurs in the LAN, the effect that the DSLAM can prevent erroneous determination is obtained.

  In the above description, an example in which the present invention is applied to an xDSL device has been described. However, DSLAM is an E-PON ONU (optical line termination device), and CPE is an E-PON OTL (customer side device and optical termination device). It is applicable to E-PON (Ethernet Passive Optical Network). Further, if the DSLAM is replaced with a collective MC on the MC (media converter) station side and the CPE is replaced with a stand-alone MC on the user home side of the MC, the present invention can also be applied to the MC device. Here, Ethernet is a registered trademark of Xerox Corporation.

1 is a configuration diagram of a communication system including DSLAM and CPE according to the present invention. FIG. 2 is a functional block diagram of a DSLAM according to the present invention. FIG. 2 is a functional block diagram of a CPE according to Embodiment 1. FIG. 6 is a functional block diagram of a CPE according to Embodiment 2. FIG.

Explanation of symbols

201 xDSL / I / F unit 202 Transmission / reception control unit 203 Quality detection unit 204 Signal detection unit 205 Device state determination unit 206 Line state determination unit 207 Data storage unit 208 Initialization setting unit 209 Loop test execution unit 210 CPU
211 ROM
212 RAM

Claims (6)

Monitors the quality of control signals that flow through the control channel formed between DSLAM (intra-station multiplexing equipment) and CPE (customer premises equipment) and carrier data signals that flow through user traffic that is formed between DSLAM and CPE A quality detector to
A loop test execution unit that operates at a predetermined time interval, transmits a predetermined control signal set in advance to the control channel, and receives a response signal to the control signal from the CPE;
A device state determination unit that determines a device state of the CPE based on a quality monitoring result of the control signal by the quality detection unit during operation of the loop test execution unit;
An xDSL comprising: a line state determining unit that determines a line state based on a quality monitoring result of the carrier data signal by the quality detecting unit when a determination result of the device state determining unit is normal. DSLAM for the system. When the determination result by the line state determination unit is a line state abnormality,
2. The xDSL system according to claim 1, further comprising an initialization setting unit that stops user traffic formed between the DSLAM and the CPE and executes an initialization setting process for the CPE device. DSLAM for.   2. The xDSL system according to claim 1, further comprising a data storage unit that preliminarily stores a threshold value used for device state determination by the device state determination unit and a threshold value used for line state determination by the line state determination unit. DSLAM for. A quality detector for monitoring the quality of the control signal flowing through the control channel formed between the CPE and the DSLAM and the quality of the carrier data signal flowing through the user traffic formed between the CPE and the DSLAM;
A loop test execution unit that operates at a predetermined time interval, transmits a predetermined control signal set in advance to the control channel, and receives a response signal to the control signal from the DSLAM;
A device state determination unit that determines a device state of the DSLAM based on a quality monitoring result of the control signal by the quality detection unit when the loop test execution unit is in operation;
A line state determination unit that determines a line state based on a monitoring result of the carrier data signal by the quality detection unit when a determination result of the device state determination unit is normal ;
A LAN / I / F unit connected to a LAN transmission line having a predetermined information device;
A predetermined control signal is transmitted to the LAN transmission line at a predetermined time interval via the LAN / I / F unit, and a response signal of the control signal is received, and the LAN transmission line An autonomous diagnosis execution unit that generates a LAN abnormality notification if the determination result is an abnormal state .
The autonomous diagnosis execution unit, when receiving a predetermined control signal predetermined at the predetermined time interval from the DSLAM described above, includes the LAN abnormality notification in a response signal of the control signal. CPE for the system. When the determination result by the line state determination unit is a line state abnormality,
5. The xDSL system according to claim 4, further comprising: an initialization setting unit that stops user traffic formed between the CPE and the DSLAM and executes an initialization setting process for the DSLAM. CPE.   5. The xDSL system according to claim 4, further comprising: a data storage unit that preliminarily stores a threshold value used for device state determination by the device state determination unit and a threshold value used for line state determination by the line state determination unit. CPE for.

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