JPS6161596A - Optical channel of time division-type - Google Patents

Abstract

PURPOSE:To reduce hardware and to simplify a control by using not only a wavelength multiplex technique but also a time division multiplex technique and constituting a non-closed optical channel only through controls of the wavelength conversion of an optical signal and its phase. CONSTITUTION:When a multi-optical signal of a wavelength lambda arrives from input highways 1-1 and 1-2, the wavelength lambda is converted in accordance with control information of a control part 13 in order to input said signal to wave length converter circuits 2-1 and 2-2 and to convert a time slot. An optical signal from the wavelength converter circuits 2-1 and 2-2 is inputted to gate-type optical switches 3-1 and 3-2 to sample the input optical signal at a high speed and to joint it by a coupler 4, and the input optical signal is wave-divided at every wavelength by an optical wave divider 5. Then it is delayed through optical delay lines 6-1-6-n to synthesize it by a wave synthesizer 7. After the synthesized optical signal is branched at each output highway by an optical wave branching device 8, the desired signal can be taken out from gate-type optical switches 9-1-9-n and subjected to the wavelength conversion. Then it is subjected to the speed conversion and transmitted to output highways 12-1 and 12-n.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical channel of a time-division optical exchange that exchanges light (a) on a time-division multiplex transmission path as it is.

1 [Prior Art] Conventionally, in a time-division optical communication path that inputs and outputs multiple time-division multiplex highways, when exchanging a time slot on an input highway with an arbitrary time slot on an arbitrary output highway, an electrical signal is used. As in the case of , it is conceivable to have a T-5-T configuration in which an optical time switch that exchanges time slots within the same highway and an optical highway switch that exchanges time slots 1- between highways are combined. ing. However, in order to reduce the blockage probability, this configuration requires a so-called cross-shaped configuration or rearrangement control in which the degree of expansion of the optical highway switch is multiplied by (2n-1), which increases the amount of hardware. However, it also has the disadvantage that control is complicated.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a time-division optical communication path that eliminates the above-mentioned conventional drawbacks, eliminates hardware, and simplifies control.

[Structure and operation of the invention] The present invention uses both wavelength division multiplexing technology and time division multiplexing technology in an optical time division switching system whose input and output are highways in which 11 pieces of information are time division multiplexed and transmitted. By doing so, highways and time slots can be exchanged arbitrarily. below.

An embodiment of the present invention will be described in detail using the drawings.

FIG. 1 is a diagram showing an embodiment of the present invention, in which optical signals in arbitrary time slots on two input highways are guided to arbitrary time slots on two output highways. In FIG. 1, 1-1 and 1-2 are input highways, 12-1 and 12-2 are output highways, and between these are a wavelength conversion circuit 2-1, 2-2 and a gate type optical switch 3-1. .3-2 and an optical multiplexing unit consisting of an optical coupler 4;
An optical delay section consisting of an optical demultiplexer 5, an optical delay line 6-1.6-2.6-3, and an optical multiplexer 7, an optical splitter 8, a gate type optical switch 9-1.9-2, and a wavelength Conversion circuit to-i, 10-
2 and an optical monomultivibrator 11-1. 13 is a control unit which includes a wavelength conversion circuit 2-1.2-2 of an optical multiplexing unit and a gate type optical switch 3-1.3-2. This is a part that controls the gate type optical switch 9-1.9-2 and the wavelength conversion circuit 10-1.10-2 of the optical separation section according to the intended switching operation information given in advance.

Figure 2 is a timing chart explaining the replacement operation in Figure 1.For convenience, the input/output highway 1-1゜1-2.12
-1.1.2-2 shows an example in which three channels of optical signals each consisting of one bit are multiplexed. Below, the multiplexed channels of input highway l-1 are expressed as Δ, B, C, The multiplexed channels of the input highway 1-2 are set to E and F, and A and F are exchanged to create the output highway 2.
The operation shown in FIG. 1 will be explained by taking as an example the case where the angle is led to -1°12-2.

Multiplexed optical signals of wavelength λ arrive from input highways l-1 and 1-2 (Fig. 2a, b). This optical signal is input to the wavelength conversion circuit 2-1, 2-2, and in order to exchange time slots, the wavelength is changed from λ to λ according to the control information of the control unit 13.
O~λ2 (Fig. 2 c, d). λ0. λ1. λ
2 are the rear optical delay lines 671. This corresponds to delay times 0, T, and 2T of C1-2 and C6-3. In the example in Figure 2.

The optical signal of channel A is λ2. The optical signal of channels B-H is λ0. Convert the optical signal of channel F to λ1. The optical signal output from the wavelength conversion circuit 2 1+2 L is input to the gate type optical switches 3-1, 3-2, and each gate type switch 3 is operated at twice the speed of the input highway speed according to the control information of the control unit 13. -1.3-2 is turned on/off to sample the input optical signal at high speed. However, in order to realize exchange operation between highways, the sampling phase is controlled (FIG. 2, 11m). In the example in Figure 2, channels B, C
, F are sampled in the first half of the bit (time slot), and the optical signals of channels A, D, and H are sampled in the second half of the bit. The optical signals output from the optical switches 3-1 and 3-2 are combined by the optical coupler 4 (FIG. 2g).

The optical signal between the two input highways coupled by the optical coupler 4 is demultiplexed into wavelengths by the optical demultiplexer 5 7
After that, an optical delay line such as an optical fiber 6-1.6-2゜6-
3 are subject to delays of O, T, and 2T, respectively (see Figure 2,
In the example of FIG. 2, channel A is delayed by two time slots and channel F is delayed by one time slot. The optical signals of each wavelength outputted from the optical delay line 6-1.6-2.6-3 are combined by the optical multiplexer 7 (Fig. 2k).

The optical signal multiplexed by the optical multiplexer 7 is input to the optical branching device 8, and after branching for each output highway, the gate type optical switch 9-1. (Fig. 2, 11m). In the example of FIG. 2, in the gate type optical switch 9-1, the first half of the pin 1-,
The gate type optical switch 9-2 takes out the second half of the pin 1-. The optical signal output from the gate type optical switch 9-119-2 is input to the wavelength conversion circuit 10-1.
It is converted to the original wavelength λ (FIG. 2, 11m). The optical signals wavelength-converted by the wavelength conversion circuits 10-1, 10-2 are further transmitted to the optical monomulti 11-1. It undergoes speed conversion by LL-2 and returns to the original optical signal speed.

Sent to output highway 12-1.12-2 (second
Figure 11mq).

FIG. 3 is a diagram showing another embodiment of the present invention, in which an input highway 1-1.1-2 and an output highway 12-1.12-2
Between the wavelength conversion circuit 2-1.2-2 and gate-type light, an optical multiplexing section consisting of switch 3-1.3-2 and optical coupler 4, optical branching circuit 14 and gate-type optical switch 15- 1.15-
2.15-3 and optical delay line 18-1.18-2.18-3
and an optical delay section consisting of an optical coupler 16, and an optical separation section consisting of an optical demultiplexer 17, a wavelength conversion circuit 10-1.10-2, and an optical mono-multivibrator 11-1.11-2. It is. In the case of Figure 3.

Wavelength conversion circuits 2-1, 2-2 of the optical multiplexing section, gate type optical switch 3-1.3-2, gate type optical switch 15-1.15-2.15-3° of the optical delay section and optical The wavelength conversion circuits 10-1 and 10-2 of the separation section are controlled by the control section 13 according to the target exchange operation information.

FIG. 4 is a timing chart explaining the exchange operation of FIG. 3, and similarly to FIG. 2, it shows an example where three channels of optical signals each consisting of one bit are multiplexed on the input/output highway. Here again, the operation of FIG. 3 will be explained using as an example the case where channel A of the human-powered highway 1-1 and channel F of the input highway 1-2 are exchanged to lead to the output highway 12-1.12-2.

Multiplexed optical signals of wavelength λ arriving from input highways l-1 and 1-2 are input to wavelength conversion circuits 2-1 and 2-2.
Figures a, b), in order to perform the highway exchange, the control unit 13
The wavelength is changed from λ to λ1 according to the control information of λ1. Convert to λ2 (Fig. 4 c+d).

λ1. λ2 is the output highway 12-1゜12-
It corresponds to 2. In the example of FIG. 4, channels A, D,
H optical signal to λ2. Channels B and C.

Convert the optical signal of F to λ1. Gate type optical switch 3
-1.3-211. It turns on/off at a speed three times the input highway speed according to control information from the control unit 13, and samples the optical signal output from the wavelength conversion circuit 2-1.2-2 at high speed. However, in order to realize the time slot exchange operation, the sampling phase is controlled (see Figure 4a,
f). In the example of FIG. 4, the optical signal No. 46 to the channel is the third one of the three divided time slots of one bit of the highway (l time slot), and the optical signal of channels B-H is the first one,
The optical signal of channel F is sampled at the second tf phase. In this way, the wavelength-converted and high-speed sampled optical signals are combined by the optical coupler 4 (Fig. 2g)
.

After the optical signal output from the optical coupler 4 is branched by the optical branching device 14, the gate type optical switch 15-1゜15-2.15
-3 for high-speed sampling. The gate type optical switches 15-1.15-2 and 15-3 are connected to the gate type optical switches 3-1.3-, respectively, according to the control information of the control unit 13.
It turns on at the first to third phases corresponding to the sampling of 2. The optical signal passing through the gate type optical switch 15-1.15-2゜15-3 is transferred to the optical delay line 18-1゜18.
-2.18-3 respectively O, T-T/3゜2 (T-
T/3) (4th diagram, i+1
j). The T/3 correction term is the later optical monomulti 11-1.
This is for making the input optical signal pulses to 11-2 equally spaced. In the example of FIG. 4, channel A is delayed by two time slots 1- and channel F is delayed by l time slots. The optical signals output from the optical delay lines 18-1.13-2.18-3 are combined by the optical coupler 16 (Fig. 4k).

The optical signal output from the optical coupler 16 is input to the optical demultiplexer 17 and is demultiplexed into each output highway (Fig. 4, 19m).
. The wavelength conversion circuit 10-1.10 converts each of the demultiplexed optical signals into
-2, respectively converted to the original wavelength λ.
m), and further optical monomulti 11-1. , 11-2, the speed is converted back to the original optical signal speed, and the output highway 1
2-1°12-2 (Fig. 2 p+q).

FIG. 5 is a diagram for explaining that the communication channel configuration in FIG. 1 is a non-obstructed type, and is a diagram illustrating that the communication channel configuration in FIG. 1 is a non-blocking type.

j k (i=1-3. j=1-2. k=1-3)
Each plane i is the time slot of the input highway, and each column j is the phase at the time of multiplexing corresponding to the output highway number, j = 1.
j = 2 corresponds to the sampling of the first half of 1 bit, j = 2 corresponds to the sampling of the latter half of 1 bit, each row corresponds to a time slot on the output highway, and is related to the time slot of the input highway by wavelengths λ0 to λ2. . Each grid point M i
The empty state is −J+ through i=1 to 3 of h jr k
4 corresponds to the empty time slot of the output highway defined by k, similar to the example of FIG.

The input highways have A, B, C, and E respectively.

There are F optical signals and j=1. The second t;th timeslot of the output highway 1 (HWI) corresponding to =2
As an example, the case where TS2) is empty and any one of A to F is connected to it is shown with diagonal lines. In this case j=
1. The lattice points Ml corresponding to =2, 1, 2 . M2,1,
2, M3, and 1.2 are all empty, and the input signal A
Or select lattice point M1.1.2 when connecting D, select M2.1.2 when connecting B or E,
When connecting C or F, use M3. By selecting L, 2, it is possible to connect without colliding with signals of other channels. As in this example, as long as the time slot of the output highway defined by j, is empty, the grid point M
It is shown that i, j, and k are selectable and the communication path is unblocked.

Also, in the case of Fig. 3, it can be determined that one channel is non-blocking by interchanging the relationship between the rows and columns in Fig. 5 and associating each column with the wavelength and each row with the phase at the time of multiplexing. shown.

FIG. 6 is an example in which the configuration of FIG. 1 is expanded to include n highways with m multiplexes. As is clear from the figure, by at most m optical fiber delay lines.

Any exchange of a total amount of X n channels of optical signals can be performed.

〔Effect of the invention〕

As explained above, in the present invention, by using both wavelength division multiplexing technology and time division multiplexing technology, a non-blocking optical communication path is constructed that performs arbitrary exchange by controlling only two points: wavelength conversion and phase of optical signals. As a result, it can be expected to reduce hardware and simplify control.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing one embodiment of the present invention, FIG. 2 is a timing diagram for explaining the operation of FIG. 1, FIG. 3 is a diagram showing another embodiment of the present invention, and FIG. FIG. 3 is a timing diagram for explaining the operation, FIG. 5 is a diagram for explaining that the communication path configuration according to the present invention is a non-blocking type, and FIG. 5 is a diagram that is an expanded version of the configuration in FIG. be. 1-1.1-2...Input highway, 2-1゜2
-2... Wavelength conversion circuit, 3-1.3-2... Gate type optical switch, 4... Optical coupler, 5... Optical demultiplexer, 6-1.6-2.6 -3... Optical delay line, 7
...Optical multiplexer, 8... Optical splitter, 9-1.9
-2...Gate type optical switch, 10-1.10-
2...Wavelength conversion circuit, 11-1.11-2...
Optical mono multivibrator, 12-1.12-2・
... Output highway, 13... Control section, 14...
・Optical splitter, 15...Gate type optical switch, 1
6... Optical coupler, 17... Optical demultiplexer, 1g-1
, 18-2, 18-3... optical delay line. A certain 2 ``2■] Moenini''・82人I 入O ■ '']L 1■ Go crazy j rom ■ - Nigochode lΔ ■ Gochoshimoguchi] 1-L Fig. 4 2 ■ -' 2 plates - 1 Figure 5 (+=2) Procedural amendment (method) February 1985 G-1, case description 1985 Patent Application No. 18339-2, name of invention Time sharing Relationship to Katamiko Channel 3, Amendment Case Applicant Address 1-1-6 Uchisaiwai-cho, Chiyoda-ku, Tokyo Name
(422) Nippon Telegraph and Telephone Public Corporation Representative Tsune Shindo 4o Agent address 201-5 Nishikigei Building, 2-38-12 Yoyogi, Shibuya-ku, Tokyo 151 Date of amendment order 1 January 9, 1985 (Date of dispatch Showa January 29, 1960) 8. In the fourth line of page 15 of the Statement of Contents of the Amendment, the statement ``Figure 5 is'' is corrected to ``Figure 6 is''. that's all

Claims (2)

[Claims] (1) In a time-division optical channel that arbitrarily exchanges optical signals on multiple time-division multiplexed input/output highways, multiple wavelength conversions convert the optical signal on each input highway to a wavelength that indicates the exchange of the corresponding time slot. a plurality of gated optical switches that sample the output optical signal from each wavelength conversion circuit at a higher speed than the input highway speed and associate the sampling phase with the corresponding output highway; An optical multiplexing section consisting of an optical coupler for coupling, an optical demultiplexer for demultiplexing the optical signal output from the optical multiplexing section into each wavelength, and a delay that differs for each wavelength of each demultiplexed optical signal. An optical delay unit consisting of a plurality of optical delay circuits that delay by the amount of time and an optical multiplexer that combines the output optical signals from each optical delay circuit, and branches the optical signals output from the optical delay unit to each output highway. an optical splitter that samples each output optical signal of the optical splitter and detects the optical signal on the corresponding output highway; The optical separation unit is made up of multiple wavelength conversion circuits that convert wavelengths into wavelengths, and multiple optical mono-multivibrators that converts the speed of the output optical signals from each wavelength conversion circuit, returns them to the original optical signal speed, and sends them to the corresponding output highway. What is claimed is: 1. A time-division optical communications path characterized by comprising: (2) In a time-division optical channel that arbitrarily exchanges optical signals on multiple time-division multiplexed input/output highways, multiple wavelength conversions convert the optical signal on each input highway to a wavelength that indicates the exchange on the corresponding highway. circuit, a plurality of gated optical switches that sample the output optical signal from each wavelength conversion circuit at a faster rate than the input highway speed and associate the sampling phase with a corresponding time slot; An optical multiplexing section consisting of an optical coupler for coupling, an optical branching device for branching the optical signal output from the optical multiplexing section into a plurality of parts, and a plurality of gate types for sampling each branched optical signal at different phases. an optical delay section comprising an optical switch, a plurality of optical delay circuits that delay the output optical signals from each gate type optical switch by different delay amounts, and an optical coupler that combines the output optical signals from each optical delay circuit; an optical demultiplexer that demultiplexes the optical signal output from the optical delay unit for each output highway; a plurality of wavelength conversion circuits that convert the wavelength of each output optical signal from the optical demultiplexer to its original wavelength; A time-sharing device characterized by comprising an optical separation unit comprising a plurality of optical mono-multivibrators that converts the speed of the output optical signal from each wavelength conversion circuit, returns it to the original optical signal speed, and sends it to the corresponding output highway. Shape optical channel.