JPS58202634A - Optical data way system - Google Patents

Abstract

PURPOSE:To reduce the loss which is due to a switch, by using a switch to have a connection between a main optical fiber cable which gives a loop connection among optical switches provided to each block and a secondary optical fiber cable which gives a loop connection among stations within the block. CONSTITUTION:A loop connection is given among groups of stations 6011- 6013...6041-6042 via a secondary optical fiber cable 5011, and a loop connection is secured for a main optical fiber cable 300 via switches 401-404. The switches 401 and 404 are turned on for transmission of information to the station 6042 from the station 6011. The optical signal transmitted toward an arrow (a) from the station 6011 is relayed at stations 6012 and 6013 to be sent to the cable 300 through the switch 401 and then to the station 6042 via the switch 404 and through the station 6041. As a result, the optical signal has only a loss due to a switch per block. This system can reduce the loss of a data way.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an optical dataway system in which data transmission between stations is performed via optical fiber cables.

[Technical background of the invention]

In general, this type of optical data way system, as shown in FIG.
=1, 2, -n). Station 2001 (1) used in the optical dataway system
=1, 2...n) has an optical switch 2101, an optical repeater 220, a line interface 2301, and a station control section 2401, as shown in FIG. Thus, when station 2001 is powered on, station 2001 is connected to fiber optic cable 100 by optical switch 2101 as shown in FIG. On the other hand, when the station 2001 is powered off, the station 2001 is disconnected from the optical fiber cable 100 by the optical switch 210i, unlike in FIG. 2, and enters the high-speed state. Then, data transmission is performed between stations that are powered on.

In such an optical dataway system, it is necessary to consider transmission loss of the optical switch. This is because there is a limit to the number of stations that can be connected in multiple stages due to the transmission loss of the optical switch, and this becomes a problem especially when a large number of consecutive stations are powered off. For example, in the system shown in FIG.
04.20 On-, power is on and station 200. , 2005.200. ~200n-,,20
If station 200.0n is not powered, then station 200.
.

Data transmission between 2004 and 2004 is bypassed stage'・1
11: This can be done via station 2003, which is in a bypass state, because the number of stages is small, but station 200. , 200n-, the data transmission between the stations 2004 and 200n is impossible because there are many bypass stages between the stations 2004 and 200n. Such problems occur in office automation systems (OA) to which the optical dataway system shown in Figure 1 is applied.
system). In other words, in such a system, each station is distributed, for example, on each floor of one building, and the administrator who turns on/off the power is different for each floor, so it is difficult to control the power supply of many consecutive stations at once. It is common for the station to be turned off and all of the stations in question to be in a hot state.

In the above example, stations 200□ and 200n.

If data transmission between stations 2002 and 200n is not performed normally due to loss of optical switch 200H, the system enters loopback mode.

11, as shown in FIG.
INK) is configured (in the figure, stations shaded with diagonal lines indicate that they are in a power-on state). This is station 2002.200n-.

line interface 2301 (l=2, n-
1). As a result, station 200□.

Stations 200 . ．． This is done via 2θOn. By the way, in the system shown in Fig. 1, the optical fiber cable 100 is a two-core optical fiber cable, and each station 2001 to 200n is provided with a U-LINK configuration function, but this is originally intended to prevent cable breakage, station failure, etc. The purpose is to reduce the impact that failures have on the system. However, in the above example, the U-LINK configuration is necessary even if no failure occurs, so even in a system that does not take failure into account, a two-core optical fiber cable (that is, a duplicated optical fiber cable) is required. The U-LINK configuration function that each station had was essential. In addition, even in a system that is equipped with two-core optical fiber/inter-cable and U-LINK configuration functions as in the example above in order to reduce the effects of failure, for example, a cable break near station 2001 can cause Turn off the system 20θ, υM, and turn off the station 200. , 200n, if a U-LINK is configured between stations 2002゜200, , 2
00n-, if only station 200.00n- is powered on. , 200n-, data transmission between them becomes impossible.

[Problems with background technology]

As described above, in conventional optical dataway systems, there is a limit to the number of stations that can be bypassed in multiple stages due to the transmission loss of optical switches.・There was a problem in which it was extremely difficult to transmit data that had been compromised. In addition, in the conventional optical data way system, expensive optical switches must be installed at all stations, resulting in an increase in system cost.

[Purpose of the invention]

The present invention has been made in view of the above circumstances, and its purpose is to:
To provide an optical data way system that requires fewer optical switches than the number of stations and has a low system price.

Another object of the present invention is to provide an optical dataway system that can always secure a line even if a large number of consecutive stations are powered off at once.

[Summary of the invention]

In the present invention, there is a main optical fiber cable that loop-connects the optical switches provided in each block, and a gang fiber cable that is provided in each block and loop-connects the optical switches of the corresponding block and a plurality of stations that constitute the corresponding block. I am trying to install a cable. Then, by switching the optical switch, the clique fiber cable of the corresponding block is connected to the main optical fiber cable via the optical switch, and the reverse optical fiber cable becomes part of the loop whose main fiber is the main optical fiber cable. Alternatively, the gang fiber cable is disconnected from the main optical fiber cable, and the block corresponding to the bypass function of the optical switch is placed in the bypass state. As a result, even if a block with multiple stations is in a bypass state, the optical switch loss is 1 regardless of the number of stations that make up the block.
The loss is only for one optical switch.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described with reference to the drawings. Note that this embodiment is a case where the present invention is implemented in an optical data way system that does not have a failure countermeasure function such as a U-LINK configuration function. In the system shown in FIG. 4, 300 is a main optical fiber cable serving as the backbone transmission path of the optical data way system, and 401 to 404 are optical switches installed in blocks. The optical switches 401 to 404 are loop-connected to the main optical fiber coil 300. 501 to 5.04 are gang fiber cables serving as transmission paths for each block. Optical switch 401-4
04 connects the gang fiber cables 501 to 504 of the corresponding block to the main optical fiber cable 300 in the switch-on state, and connects the reverse optical fiber cable 50 to the main optical fiber cable 300.
1 to 504 as part of a loop mainly including the main optical fiber cable 300. Also, light switch 4
01 to 404 disconnect the gang fiber cables 501 to 504 of the corresponding blocks from the connection with the main optical fiber cable 300 in the switch-off state, and use their own bypass function to connect the corresponding blocks to PiA? It is designed to be in a state of 601. ~601. is a station loop-connected to the gang fiber cable 501,
602. ~602. is a station loop-connected to the cabling fiber cable 502. Also, 60B, ~
6033 is a station loop-connected to the cabling fiber cable 503; 604. ．． 6042 is a station connected to the gang fiber cable 504 in a loop. These stations 6011-6018.602. ~
6023.6031-6033.604. , 604
．． differs from the conventional example in that it does not have an optical switch. In addition, station 601. ~6013.602. ~602
8.603. ~6033.604. , 604. , an optical repeater having a transmitting/receiving circuit, a clock extraction circuit, a parallel/serial-to-serial/parallel converting circuit, and a line interface having a circuit for capturing/relaying information, etc.
Station control units that control line interfaces and perform data transmission with other stations are omitted.

Next, the operation of one embodiment of the present invention will be explained. First, for example, station 601. ~601. When using a block having stations 6011-601. At the same time, the optical switch 401 is turned on.

When the optical switch 401 is turned on, the gang fiber cable 501 switches to the optical switch 4 as shown in FIG.
01 to the main optical fiber cable 300. Also, station 604. , 604° is also used, stations 604 . ．． 6
04. The optical switch 404 is turned on and the optical switch 404 is turned on.
Turn on. When the optical switch 404 is turned on, the gang fiber cable 504 is connected to the main optical fiber cable SOO through the optical switch 404, as shown in FIG. Accordingly, the main optical fiber cable SOO,
A loop transmission path consisting of gang fiber cables 501, 504 is constructed, and stations 60-601. and station 604. .

6042 is connected to a line. On the other hand, the optical switch 402.
403 is turned off in this embodiment, and the corresponding gang fiber cables 502 and 503 are disconnected from the main optical fiber cable 300 as shown in FIG. The optical switches 402 and 403 have 2
The corresponding block is in a pinosus state due to the 4797 function.

In this state, station 601. It is assumed that optical information is transmitted from station 6042 to station 6042. In FIG. 5, an optical signal sent from station 60 (a transmitter of an optical repeater, not shown) onto gang fiber cable 501 in the direction of arrow a is transmitted to station 6012.601.
．． The main light is relayed via the light switch 401.
It is sent out on cable 300. The optical signal sent onto the main optical fiber cable 300 is transmitted to the gang fiber cable 504 via the optical switches 402, 403 and the optical switch 404, which are in the passive state, in order. The optical signal transmitted to the gang fiber cable 504 is relayed at the station 604, and then the optical signal is transmitted to the station 604.
Reach 042 d.

In this embodiment, the optical signal sent from station 6011 is attenuated by optical switches 401 to 404;
Since the number of stages is as small as 4, the amount of attenuation between stations 6011 and 6042 (D data transmission is not so much as to be adversely affected. In other words, according to this embodiment, 11, . . .

station 602. ~6o2. Ya station 60
Even if the power of 31 to 6033 is off, the optical signal does not pass through these stations by the optical switches 402 and 403, and only one optical switch is required for one block, so the optical signal is attenuated. The amount is significantly reduced compared to the prior art, which suffers losses in all these powered-off stations. For this reason, as in the past, U-LIN
station 6 without configuring K and making a line connection.
01. , 604. Data transmission between the two can be performed normally.

Therefore, in this embodiment, which does not take into account countermeasures in the event of a failure in the optical dataway system, the optical fiber cable is or by providing two sets of transmitter/receiver circuits in the optical repeater of each station, or by adding a switching function or U-LI for the two sets of transmitter/receiver circuits to the line interface.
There is no need to provide any functions constituting the NK.

However, there is a limit to the number of optical switches that can be connected to the main optical fiber cable as the backbone transmission line. Now, the number of optical switches that can be connected is determined by the automatic gain variable range of the optical repeater in the n1 station.

The loss of one stage of an optical switch is B aB (it can be considered that there are cases where it is a pi-gusu and cases where it is not, but in general, there are many optical switches that have almost the same standard for both losses, so it is assumed to be BdB in both cases. ), and cable loss is LdB, there is a relationship between n, A, B, and L as follows: A≧BXn+, that is, n≦(A − L )/B. A typical value is A=24dB.

If B = L = 3 dB, n≦7 is obtained,
In this example, it can be seen that the maximum number of optical switches that can be connected to the backbone transmission line is seven, that is, the maximum number of blocks constituting the system is seven. Therefore, if the number of stations forming each block is three (not limited to three, but may be four or more), the number of stations forming the system will be 21. On the other hand, in conventional optical dataway systems that do not have a U-LINK configuration function, the number of stations that make up the system must be There are at most 7 units.

Furthermore, even if a U-LINK configuration function is provided, in order to ensure inter-station data transmission under the above conditions, the maximum number of stations configuring the system must be kept to 14. It is not possible to construct a large-scale optical dataway system.

In the above embodiment, the main optical fiber cable 300 is not duplicated and each station does not have a U-LINK configuration function, but the main optical fiber cable and each gang fiber cable The optical switch will be made into two circuits as in the conventional example, and each station will have a J-LINK configuration function.
When a failure occurs, the system may be set to loop-to-back mode to reduce the influence of the failure. In this case, under normal conditions without any failures, the U-LI should be set to loop puncture mode.
There is no need to configure the NK, so the modes can be saved until a failure occurs.

By the way, when the present invention is applied to an in-building OA (office automation) system, it is convenient to group the required stations on each floor into one or more blocks.

〔Effect of the invention〕

As described in detail above, according to the optical data way system of the present invention, the number of optical switches is smaller than the number of stations, so the system price can be reduced.

Further, according to the present invention, a line can always be secured even if a large number of consecutive stations are powered off at once.

[Brief explanation of drawings]

FIG. 1 is a system configuration diagram showing a conventional example, FIG. 21 is a block diagram showing a station configuration of the system of the conventional example, FIG. FIG. 4 is a system configuration diagram showing one embodiment of the present invention, and FIG. 5 is a system state diagram for explaining the operation of the above embodiment. 2001 (1=1~n), 601□~6018, 6o2
1-602,. 603. ~60B8,604. ,604
2...Station, 2101, 401-404
...Optical switch, 300...Main optical fiber cable (backbone transmission line), 501-504...Clique fiber cable 0

Claims (1)

[Claims] A backbone transmission line consisting of a main optical fiber cable, an optical switch provided in each block and connected in a loop to this backbone transmission line, and a loop connection between this optical switch and multiple stations that make up the corresponding block. The optical switch connects the backbone transmission line and the slave fiber cable of the corresponding block by switching the switch, and connects the backbone fiber cable to the loop including the backbone transmission line. It is characterized by being configured so that either the function of separating the drawn fiber cable from the connection with the above-mentioned core transmission line and the function of binosing the corresponding block is exerted. Optical data way system.