JPH04312037A - Fault informing system - Google Patents

Abstract

PURPOSE:To prevent a state that out-of-frame-synchronization is being detected at a user's house from affecting an up signal from another user's house, by informing a point side of the out-of-frame-synchronization fault of a multipoint side in a prescribed way. CONSTITUTION:A certain no-signal section (x) is provided on the frame format Sa of a down direction, and a signal section (y) to inform the out-of-frame- synchronization fault is provided on the frame format Sg of an up direction. Then, at the carrier detection circuit 21 of a user's house side, it outputs an information signal Se at the time of detecting the no-signal section (x) of the received frame format Sa. Besides, at a frame synchronization circuit 15, it loads the information signal Se to the signal section (y), and outputs it to a central telephone exchange together with frame data at the time of detecting the out-of-frame--synchronization, and makes a fault information signal detection circuit 19 detect the information signal so as to inform it of the out-of-frame- synchronization fault.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] This invention notifies the point-side device of a failure detected by the multi-point device when point-to-multipoint transmission is performed in a multi-star network consisting of passive nodes. This relates to failure notification methods.

0002

2. Description of the Related Art FIGS. 4 and 5 are system configuration diagrams and device configuration diagrams for explaining conventional failure notification systems. In FIG. 4, 1 is a telephone office, 2 is a passive optical branch/coupler, 3 is a user's home, 4 is an optical fiber, 5A is a point-side transmission device placed in the telephone office, and 6A is a multipoint point placed in the user's home. This is the side transmission device. In FIG. 5, 7 is a multiplexing circuit, 8 is a frame generation circuit of the transmission device 5A, 9 is an optical/electrical conversion circuit of the transmission device 5A,
10 is a data reproducing circuit of the transmission device 5A, 11 is a frame synchronization circuit group of the transmission device 5A, and 12 is a frame synchronization circuit, the number of which corresponds to each user's home. 13 is an optical/electric conversion circuit of the transmission device 6A, 14 is a data reproduction circuit of the transmission device 6A, 15 is a frame synchronization circuit of the transmission device 6A, 16 is a phase control oscillation circuit, 17 is a frame generation circuit of the transmission device 6, 18 is a gate circuit.

Next, the operation will be explained using FIG. 6. FIG. 6 is a timing chart showing the timing relationship of each part. Downlink data a that has been time-division multiplexed on a user-by-user basis is transmitted from the telephone station 1 to the user's home 3 via the optical splitter/combiner 2 in the downlink direction. At the user's home 3, the user detects data c1 assigned to him/her from the downlink data a. When the downlink data a is received, uplink data b1 is sent to the telephone station 1 at a predetermined timing t1. At the receiving end of the telephone station 1, uplink data b is received in which uplink data from each user's home is time-division multiple accessed. The above description will be explained in more detail.

[0004] A multiplexing circuit 7 time-division multiplexes data c1 for each user's home on a user-by-user basis to generate a data string c. A frame generation circuit 8 adds a frame synchronization signal e to enable recognition of the data string c at the user's home, and generates downlink data a. The optical/electrical conversion circuit 9 converts the downlink data a into an optical signal and transmits it to the user's home 3 via the optical branch/coupler 2. The optical/electrical conversion circuit 13 in the user's home 3 converts the downlink data a into an electrical signal. The data reproducing circuit 14 extracts the timing signal f from the downlink data a.

The phase controlled oscillation circuit 16 receives a timing signal f.
This is an oscillator that generates a timing signal g used in the user's home 3 that matches a frequency in a certain relationship with the frequency of , and continues to output the timing signal g by itself even if the timing signal f is no longer input. The frame synchronization circuit 15 detects the frame synchronization signal e, recognizes the frame phase of the downstream data a, and extracts data c1 assigned to a predetermined position from the beginning of the frame.

The frame generation circuit 17 adds a frame synchronization signal h to enable the telephone station 1 to recognize the data d1, and generates the data b1. The data b1 from the frame generation circuit 17 is output at timing t1 in order to correctly arrange the data b1 on the upstream data b so as not to collide with the upstream signals from each user's home. The timing t1 is predetermined for each user's home, and its value is a fixed time from the phase signal j indicating the frame phase from the frame synchronization circuit 15, and is obtained only when the frame synchronization of the downlink data a is established. It is something. The gate circuit 18 is an AND gate circuit whose one input is data b1 and the other input is a frame synchronization loss signal k indicating the frame synchronization loss detected by the frame synchronization circuit 15.

The optical/electrical conversion circuit 13 converts the data b1 into an optical signal and transmits it to the telephone office 1 via the optical branch/coupler 2. The optical splitter/combiner 2 combines data from each user's home and sends it to the telephone station 1 as uplink data b. The optical/electrical conversion circuit 9 of the telephone station 1 converts uplink data b from each user's home into an electrical signal. The data reproducing circuit 10 extracts the timing signal f from the upstream data b. A frame synchronization circuit 12 is provided corresponding to each user's home, and extracts data b1 from upstream data b, detects a frame synchronization signal h, recognizes the frame phase of data b1, and extracts data d1. If frame synchronization is not established, an out-of-synchronization signal m is output.

[0008] Therefore, if the frame synchronization circuit 15 of the user's home 3 detects frame synchronization loss at time T, timing t1 cannot be obtained, so that the uplink signals from other user's homes on the uplink data b are not affected. During this period, the frame synchronization circuit 12 of the telephone station 1 detects frame synchronization loss and outputs a frame synchronization loss signal m.

[0009]

[Problem to be Solved by the Invention] Since the conventional failure notification system is configured as described above, the frame synchronization signal m detected by the frame synchronization circuit 12 of the telephone station 1 is transmitted when the downstream data passes. There has been a problem in that it is difficult to distinguish whether the problem is caused by a fault in the circuit or a fault in the circuit through which upstream data passes.

[0010] This invention was made to solve the above-mentioned problems, and is designed to prevent the state in which frame synchronization is detected at a user's home from affecting uplink signals from other user's homes. The purpose is to obtain a fault notification method that can notify the telephone office.

[0011]

[Means for Solving the Problems] The failure notification method according to the present invention is for transmitting frame data point-to-multipoint between stations in a network with a passive multi-star configuration. The format has a certain no-signal period, and the frame format of the point side device has a signal period for notifying frame synchronization failure, and the multi-point side device receives a notification signal when detecting the no-signal period. a notification signal generating means for generating a frame data, an out-of-synchronization detection means for detecting an out-of-frame synchronization of the transmitted frame data, and an out-of-synchronization detection means for transmitting the generated notification signal to a signal section on the frame format when an out-of-synchronization is detected. A failure notification method, characterized in that the point side device is provided with an out-of-synchronization notification unit for notifying a frame out-of-synchronization failure from the transmitted notification signal of the signal section.

0012

[Operation] According to the present invention, the notification signal generation means generates the notification signal when detecting a no-signal period from the frame data from the point side device, and when the out-of-synchronization detection means detects out-of-synchronization of the frame data, the notification signal is generated. By placing the signal in a predetermined signal section provided in the frame data to the point side device, the out-of-synchronization notifying means of the point-side device detects the notification signal in the signal section and notifies the out-of-synchronization failure.

[0013]

[Example] Example 1. A network configuration diagram for explaining an embodiment of the present invention is shown in FIG. 4 used in explaining the conventional system.
is the same as FIG. 1 is a block diagram of an apparatus showing an embodiment of the present invention, and numerals 5 to 17 are the same as the conventional apparatus shown in FIG. Reference numeral 5 denotes a point-side transmission device placed in a telephone office according to this embodiment, 6 a multi-point side transmission device placed in a user's home according to this embodiment, 7 a multiplexing circuit, and 8 a frame generation circuit of the transmission device 5. , 9 is an optical/electrical conversion circuit of the transmission device 5, 10 is a data reproduction circuit of the transmission device 5, 11 is a frame synchronization circuit group of the transmission device 5,
Reference numeral 12 denotes a frame synchronization circuit, the number of which corresponds to each user's home. 13 is an optical/electrical conversion circuit of the transmission device 6, 14 is a data reproduction circuit of the transmission device 6, 15 is a frame synchronization circuit of the transmission device 6, 16 is a phase control oscillation circuit, and 17 is a transmission device 6
19 is a group of failure notification signal detection circuits for detecting a signal indicating an out-of-synchronization failure; and 20 is a failure notification signal detection circuit, the number of which corresponds to each user's home. 21 is a carrier detection circuit, 22 is a pulse signal generation circuit, and 23 is a signal from the pulse signal generation circuit 22 and a frame generation circuit 17.
This is a selection circuit that selects one of the signals from the . Further, FIG. 2 is a frame configuration diagram showing a frame configuration on a transmission path.

Next, the operation will be explained using FIG. FIG. 3 is a timing chart showing the timing relationship of each part. Downlink data sa time-division multiplexed for each user is transmitted from the telephone station 1 to the user's home 3 via the optical branch circuit 2 in the downlink direction. At the user's home 3, the user detects data c1 assigned to him/her from the downlink data sa. When the downlink data sa is received, uplink data sf is sent to the telephone station 1 at a predetermined timing t2. At the receiving end of the telephone station 1, the uplink data from each user's home is time-division multiple-connected and the uplink data s
g. The above description will be explained in more detail.

A multiplexing circuit 7 time-division multiplexes the data c1 for each user's home on a user-by-user basis to generate a data string c. A frame generation circuit 8 adds a frame synchronization signal e to enable recognition of the data string c at the user's home, and also adds a no-signal period x to generate downlink data sa. The optical/electrical conversion circuit 9 converts the downlink data sa into an optical signal and transmits it to the user's home 3 via the optical branch/coupler 2 . The optical/electrical conversion circuit 13 in the user's home 3 converts the downlink data sa into an electrical signal. The data reproducing circuit 14 extracts the timing signal sb from the downlink data sa. The phase controlled oscillator circuit 16 is an oscillator that generates a timing signal sc to be used at the user's home 3 that matches the frequency of the timing signal sb and a frequency in a certain relationship.
Even if b is no longer input, the timing signal s will run automatically.
Continue to output c.

The frame synchronization circuit 15 detects the frame synchronization signal e, recognizes the frame phase of the downstream data sa, and extracts data c1 assigned to a predetermined position from the beginning of the frame. The carrier detection circuit 21 is composed of a circuit such as a monostable multivibrator, for example, and monitors the presence or absence of a downlink signal, and outputs a signal sd when there is no signal. When the pulse signal generation circuit 22 receives the signal sd, it generates the timing signal sc.
is used to generate the pulse signal se. The pulse signal se is output at timing t3 in order to be correctly placed within the signal section y for notifying a frame out-of-sync failure on the upstream data sf so as not to collide with the upstream signal from each user's home. The timing t3 is predetermined for each user's home, and its value is a fixed time from the signal sd indicating that there is no downlink signal. Within the signal section y, notification sections are allocated to each user's home at intervals of t.

The frame generation circuit 17 adds a frame synchronization signal h to enable the telephone station 1 to recognize the data d1, and generates uplink data b1. Frame generation circuit 17
The uplink data b1 from the frame synchronization circuit 15 is output at timing t2 in order to correctly arrange the uplink data sg on the uplink data sg so that the uplink signals from each user's house do not collide with each other, based on the phase signal j from the frame synchronization circuit 15. The timing t2 is predetermined for each user's home, and its value is a fixed time from the phase signal j indicating the frame phase from the frame synchronization circuit 15, and is obtained only when the frame synchronization of the downlink data sa is established. It is something. The selection circuit 23 receives the upstream data b1 from one input and the pulse signal generation circuit 22 from the other input.
When the frame synchronization loss signal k is received from the frame synchronization circuit 15, the pulse signal se
If not, select upstream data b1 and output upstream data sf.

The optical/electrical conversion circuit 13 converts the upstream data sf into an optical signal and transmits it to the telephone office 1 via the optical branch/coupler 2. The optical splitter/combiner 2 combines data from each user's home and sends it to the telephone office 1 as uplink data sg. The optical/electrical conversion circuit 9 of the telephone station 1 converts uplink data sg from each user's home into an electrical signal. The data reproducing circuit 10 extracts the timing signal sh from the upstream data sg. A frame synchronization circuit 12 is provided corresponding to each user's home, and extracts data b1 from upstream data sg, detects a frame synchronization signal h, and recognizes the frame phase of data b1.
Extract data d1. If frame synchronization is not established, an out-of-synchronization signal m is output. A fault notification signal detection circuit 20 is provided corresponding to each user's home, and extracts a notification section to which a pulse signal se is assigned from the uplink data sg, and if the pulse signal se is present in that section, it outputs a fault notification signal sj. Output.

Therefore, if the frame synchronization circuit 15 of the user's home 3 detects frame synchronization loss at time T, timing t2 cannot be obtained, and therefore, while the synchronization circuit 15 detects frame synchronization loss, the upstream data sg In order not to affect the uplink signals from other users' homes above, the output of data b1 is prohibited, and the pulse signal se is sent only during the fault notification section y, and during this period, the fault notification signal of telephone station 1 is detected. The circuit 20 detects the pulse signal se and outputs a fault notification signal sj.

[0020]

As described above, according to the present invention, when there is a frame out-of-frame failure on the multi-point side, the signal section notifies the frame-out-of-frame failure at an appropriate timing after the signal from the point side device disappears. The effect of this is to obtain a fault notification method that can notify the central office of a state in which complaint synchronization is detected on the multipoint side, which is the user's home, without affecting uplink signals from other user's homes. There is.

[Brief explanation of drawings]

FIG. 1 is an apparatus configuration diagram showing an embodiment of the present invention.

FIG. 2 is a frame configuration diagram showing a frame configuration on a transmission path according to an embodiment of the present invention.

FIG. 3 is a timing chart showing timing relationships in an embodiment of the present invention.

FIG. 4 is a system configuration diagram.

FIG. 5 is a configuration diagram of a conventional device.

FIG. 6 is a timing chart showing a conventional timing relationship.

[Explanation of symbols]

5 Point side transmission device 6 Multi-point side transmission device 8 Frame generation circuit 10 Data reproduction circuit 11 Frame synchronization circuit group 12 Frame synchronization circuit 14 Data reproduction circuit 15 Frame synchronization circuit 16 Phase control oscillation circuit 17 Frame generation circuit 19 Fault notification signal detection circuit group 20 Fault notification signal detection circuit 21 Carrier detection circuit 22 Pulse signal generation circuit 23 Selection circuit

Claims (1)

[Claims] [Claim 1] In a network with a passive multi-star configuration in which frame data is transmitted point-to-multipoint between stations, the frame format of the multi-point side device has a certain no-signal period, and The frame format of the point side device has a signal section for notifying a frame out-of-frame failure, and the multipoint side device includes a notification signal generation means for generating a notification signal when detecting the no-signal section, The point side device includes: an out-of-synchronization detection means for detecting out-of-frame synchronization of frame data; and a notification signal transmission means for transmitting the generated notification signal to the signal section on the frame format when out-of-synchronization is detected. . A failure notification system comprising: out-of-synchronization notification means for notifying an out-of-frame out-of-frame failure from the transmitted notification signal of the signal section.