JP3001336B2 - Optical subscriber transmission equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical subscriber transmission apparatus, and more particularly to an optical subscriber transmission apparatus having a loopback function in an optical line multiplexer in a passive double star (PDS) configuration.

[0002]

2. Description of the Related Art A conventional optical subscriber transmission device will be described with reference to the configuration diagram of FIG. 2 and the signal timing diagram of FIG.

Referring to FIG. 2, an optical subscriber transmission apparatus comprises:
An optical line multiplexer 21 installed in a station, and a plurality (n) of subscriber line termination devices 23 and 24 corresponding to each subscriber.
And 25, and an optical signal which is connected to the device 21 through the optical fiber
And an optical branch 22 for branching to subscriber line termination devices 23, 24 and 25 via 7, 28 and 29, respectively. Here, the optical fibers 22, 27, 28 and 29
Are one core each. Downstream optical signals from the optical line multiplexer 21 to the optical network units 23, 24 and 25 are TDM burst signals, the optical network unit 2
The upstream optical signals from 3, 24 and 25 toward the optical line multiplexer 21 are TDMA burst signals.

[0004] Referring to FIG. 3, an optical signalized downstream burst signal A multiplexes transmission data to each of the subscriber line terminating devices 23 to 25. Subscriber line terminating devices 23 to 25
, Bn extract the transmission data to be transmitted from the burst signal A and convert the reception data into the optical signal at the timing controlled by the optical line multiplexer 21. Are sent. The optical line multiplexer 21 receives the burst signal B
1 to Bn so as not to collide with each other.
25 transmission timing.

Here, the above-mentioned optical subscriber line multiplexer 21
Does not have a loopback function for the burst signal A,
Alternatively, the electrical signal circuit portion has a loopback function of multiplexed transmission data, and the optical signal circuit does not loop back the burst signal A.

[0006]

In the optical line multiplexer of the optical line transmission apparatus described above, even if it has a loopback function, the loopback is performed in the electric signal circuit portion, so that a failure occurs. When it occurs, there is a disadvantage that it is impossible to determine whether this failure has occurred in the optical transmission / reception unit of the optical line multiplexer or in the optical line transmission line (optical fiber).

[0007]

An optical subscriber transmission apparatus according to the present invention transmits a plurality of transmission data corresponding to each subscriber to a TD.
An optical subscriber line multiplexing device for converting the M multiplexed signal to a TDM optical signal, transmitting the TDM optical signal, receiving the TDMA optical signal transmitted for each subscriber, and separating the received data into a plurality of reception data corresponding to the subscriber; A first optical splitter connected to the optical line multiplexer via a first optical fiber and splitting the TDM optical signal and the TDMA optical signal into second optical fibers corresponding to the respective subscribers; A passive double-star optical subscription comprising: a subscriber terminating device connected to one of the second optical fibers for receiving the TDM optical signal and transmitting one of the TDMA optical signals. In the subscriber transmission apparatus, the optical line multiplexer includes means for looping back the TDM optical signal.

The optical subscriber line multiplexer of the optical subscriber transmission apparatus further comprises a multiplexed burst signal generator for multiplexing the plurality of transmission data into a transmission burst signal, and transmitting the transmission burst signal to the TDM. An optical transmitting unit that converts the optical signal into an optical signal, a second optical branch that receives the TDM optical signal at a first terminal, and branches the signal into a second terminal and a third terminal.
The TDM optical signal from the second terminal of the second optical branch is transmitted to the first terminal.
Receiving the signal from the second terminal to the first optical fiber from the second terminal, receiving the TDMA optical signal from the first optical fiber at the second terminal, and generating the third signal at the third terminal. An optical branch, a first terminal receiving a TDMA optical signal from a third terminal of the third optical branch, and a second terminal receiving a TDM optical signal from a third terminal of the second optical branch; Receiving the TDM optical signal and the TDMA optical signal from the third terminal of the fourth optical branch, and generating a TDM signal and a TDMA signal of an electric signal corresponding to these signals. An optical receiver, a synchronization detector for detecting the reception data corresponding to the subscriber terminal device from the TDMA signal, a transmission data detector for detecting the transmission burst signal from the TDM signal, A drop unit that drops the data corresponding to the drop control signal from the transmitted burst signal under the control of the drop control signal, and any one of transmission data from the drop unit and reception data from one of the synchronization detection units. And a loop-back control unit that generates the drop control signal and the selection control signal.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of one embodiment of the present invention. The optical line multiplexer 20 in this figure replaces the optical line multiplexer 21 in the optical line transmission apparatus having the PDS configuration shown in FIG. 2, and shows a subscriber line interface in detail. I have.

The optical line multiplexer 20 transmits data 1 to each of the optical network units 23 to 25 (see FIG. 2).
01 is multiplexed by the multiplexed burst signal generation unit 1 and TDM
A signalized burst signal 102 results. The burst signal 102 is transmitted by the optical transmitter 2 to the optical burst signal 10.
3 (burst signal A in FIG. 3). The optical burst signal 103 is supplied to a first terminal of the optical branch 3, is branched to second and third terminals, and is divided into signals 10 and 10, respectively.
4 and 107. Signal 104 is the first of optical branch 4
The burst optical signal 105 is supplied to the
Optical fiber 26 (see FIG. 2) as (burst signal A)
Sent to

On the other hand, optical burst signals B1 to Bn (see FIG. 3) from the respective subscriber line terminating devices 23 to 25 are supplied to the first terminal of the optical branch 4 via the optical fiber 26, and these signals B1 to Bn are supplied. ＢBn are generated as signals 106 at the second terminal of the optical branch 4. The signal 106 is supplied to the second terminal of the optical branch 5 and is generated as a signal 108 at the third terminal together with the signal 107 supplied to the first terminal of the optical branch 5. The above-described downstream optical burst signal A and upstream optical burst signals B1 to B1
Since Bn is a single optical fiber line transmission line, that is, one optical fiber 26, it is temporally separated to prevent collision (see FIG. 3). Signal 108 maintains the same temporal relationship. The optical receiving unit 6 receives the burst optical signal 103 converted into a TDM signal and the signal 108 including the burst optical signals B1 to Bn converted into a TDMA signal.
8 is converted into an electric signal 109.

The burst signal B of the electric signal 109
1, B2, and Bn are the corresponding synchronization detection units 10, 1 respectively.
Synchronization is achieved by the synchronization detectors 10, 12,
14 detects received data 113, 114 and 115 corresponding to the burst signals B1, B2 and Bn, respectively.
Further, the burst signal A of the electric signal 109 is synchronized by the transmission signal synchronization detection unit 7, and the synchronization detection unit 7 detects the multiplexed transmission data 110 (same as the burst signal 102). The drop unit 8 controls the multiplex transmission data 11 under the control of the drop control signal 119 from the loopback control unit 9.
The loopback data 111 is dropped from 0. The received data 113, 114, and 115 are respectively
The loopback data 111 is supplied to one of the input terminals 13 and 15, and the loopback data 111 is supplied to the other input terminals of all the selection units 11 to 15. The loopback control unit 9 transmits the selection control signal 120,
121 and 112 are sent to all the selection units 11, 13 and 15. Based on the control of the selection control signals 120, 121, and 112, the selection units 11, 13, and 15 insert the drop data 111 into the loopback locations or select the received data 113, 114, and 115 as they are, respectively. The signals 116, 117 and 118 of the selection result are output.

[0013]

As described above, the present invention uses a TDM burst signal as a downstream optical signal and a TDMA burst signal as an upstream optical signal, and transmits these signals through one optical subscriber transmission line. Utilizing the fact that the upstream and downstream burst signals do not collide on the time axis in the optical subscriber transmission device having the configuration, the optical subscriber line multiplexer multiplexes the downstream burst signal from the optical transmission unit through the optical branch. Since the receiving unit is looped back, there is an effect that loopback including the optical transmitting unit and the optical receiving unit can be performed.

[Brief description of the drawings]

FIG. 1 is a block diagram of one embodiment of the present invention.

FIG. 2 is a configuration diagram of an optical subscriber transmission device having a passive double star configuration.

FIG. 3 is a signal timing diagram of the optical subscriber transmission device of FIG. 2;

[Explanation of symbols]

 Reference Signs List 1 multiplexed burst signal generation unit 2 optical transmission unit 3, 4, 5, 22 optical branching 6 optical reception unit 7 transmission signal synchronization detection unit 8 drop unit 9 loopback control unit 10, 12, 14 synchronization detection unit 11, 13, 15 Selector 20, 21 Optical line multiplexer 23-23 Optical line terminal 26-29 Optical fiber 101-121 Signal

Claims (3)

(57) [Claims] 1. TDM multiplexing a plurality of transmission data corresponding to each subscriber, converting the transmission data into a TDM optical signal and transmitting the TDM optical signal, and receiving a TDMA optical signal transmitted for each subscriber and responding to the subscriber. An optical subscriber line multiplexer for separating the received data into a plurality of pieces of received data; and a TDM optical signal and the TDMA optical signal connected to the optical subscriber line multiplexer via a first optical fiber. A first optical branch for branching to a second optical fiber corresponding to
An optical subscriber transmission device having a passive double star configuration, comprising: a subscriber terminating device connected to one of the optical fibers and receiving the TDM optical signal and transmitting one of the TDMA optical signals. An optical subscriber transmission device, wherein the optical line multiplexer includes means for looping back the TDM optical signal. 2. A multiplexed burst signal generator for multiplexing the plurality of transmission data into a transmission burst signal, wherein the optical subscriber line multiplexing device multiplexes the plurality of transmission data and a light for converting the transmission burst signal into the TDM optical signal. A transmitting unit, a second optical branch that is generated by receiving the TDM optical signal at a first terminal and bifurcating the signal to a second and a third terminal, and a second optical branch of the second optical branch.
A TDM optical signal from a terminal is received by a first terminal, the signal is supplied from a second terminal to the first optical fiber, and the TDMA optical signal from the first optical fiber is received by the second terminal. And a TDM optical signal from a third terminal of the second optical branch while receiving a TDMA optical signal from a third terminal of the third optical branch at a first terminal. At the second terminal, receiving the optical signals at the third terminal, and receiving the TDM optical signal and the TDMA optical signal from the third terminal of the fourth optical branch. An optical receiving section for generating a TDM signal and a TDMA signal of a signal; a synchronization detecting section for detecting the received data corresponding to the subscriber terminal device from the TDMA signal; and detecting the transmission burst signal from the TDM signal. A transmission data detection unit, a drop unit that drops data corresponding to the drop control signal from the detected transmission burst signal under the control of a drop control signal, and a transmission data from the drop unit and the synchronization detection unit. And a loop-back control unit for generating the drop control signal and the selection control signal, the selection unit corresponding to the synchronization detection unit for selecting any one of the received data from the two by a selection control signal. 1
An optical subscriber transmission device as described. 3. A multiplexed burst signal generation unit for multiplexing a plurality of transmission data corresponding to each subscriber into a transmission burst signal, an optical transmission unit converting the transmission burst signal into a TDM optical signal, and the TDM An optical signal is received by a first terminal, a first optical branch generated by splitting the signal into a second terminal and a third terminal, and a TDM optical signal from a second terminal of the first optical branch is applied to a first terminal. A second optical branch which receives the signal from the second terminal, receives the TDMA optical signal at the second terminal, and receives the signal at the third terminal, and a TDMA optical signal from the third terminal of the second optical branch. The third terminal receives the signal at the first terminal, receives the TDM optical signal from the third terminal of the first optical branch at the second terminal, and generates these optical signals at the third terminal.
And the TD from the third terminal of the third optical branch.
An optical receiving unit that receives an M optical signal and a TDMA optical signal and generates a TDM signal and a TDMA signal of an electrical signal corresponding to these signals; and a synchronization detecting unit that detects received data corresponding to each subscriber from the TDMA signal. When,
A transmission data detection unit that detects the transmission burst signal from the TDM signal, a drop unit that drops data corresponding to the drop control signal from the detected transmission burst signal under the control of a drop control signal, A selection unit corresponding to the synchronization detection unit for selecting any of transmission data and reception data from one of the synchronization detection units by a selection control signal, and a loopback control unit for generating the drop control signal and the selection control signal An optical subscriber line multiplexing device comprising: