JP3022446B2 - Polling method and apparatus for optical burst communication - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polling method and apparatus for optical burst communication in which a plurality of subscriber units and a central office communicate with each other through optical fibers via optical couplers.

[0002]

2. Description of the Related Art In an optical burst communication apparatus for communicating a plurality of subscriber units and office equipment via an optical fiber via an optical coupler, when the transmission distance between the subscriber re-installation and the office equipment is different, In the data transmission time from each subscriber device to the office equipment, an arrival time difference and a light intensity difference occur according to the transmission distance.

If the arrival time difference is large, the data is packed and there is no delay, so that the transmission band cannot be used sufficiently. Therefore, in order to reduce the arrival time difference, a delay instruction value which is a data transmission time for canceling the arrival time is set for each subscriber device. By setting this delay instruction value, the transmission band can be effectively used by reducing the time difference between the data transmitted from each subscriber device and the arrival at the station device. The setting of the delay instruction value uses a measurement result by a distance measuring device mounted on the station apparatus.

[0004] This technology uses TDMA (Time Division Multiple Access).
Widely used in satellite communications as a method.

In optical burst communication, since the light intensity differs for each optical burst, the time for following the threshold of digital data for each burst differs in the photoelectric conversion. In other words, when the light intensity difference is large, the distance between consecutive optical burst data cannot be reduced due to the high following speed, so that the transmission band cannot be used effectively.

In order to solve this difference in light intensity, Japanese Patent Laid-Open Publication No.
As described in -230607, a method of changing the threshold value for each optical burst, or presetting a photoelectric converter to a default threshold value for each optical burst,
A method of reducing the distance between optical burst signals has been adopted.

FIG. 8 shows a conventional example in which the distance between optical burst signals is reduced by presetting the photoelectric converter to a default threshold value for each optical burst. here,
The optical burst signal 51 input to the photoelectric converter 52 is:
It is preset to a default threshold value by a preset signal 63 of a preset generator 62.

According to the polling setting number signal 58 from the band setting unit 60, the polling generator 59
Is output.

FIG. 9 shows an optical burst signal 5 according to the conventional method.
FIG. 10 shows an enlarged view of a state where the optical burst signal 51 is preset.

[0010]

The problem is that even if a method of changing the threshold value for each optical burst or a method of changing the threshold value itself is used, a time for changing the threshold value is required, and an optical burst signal is required. This time must be included in determining the distance between.

The present invention has been made in consideration of the above points, and has as its object to provide a technique capable of reducing the distance between optical burst signals and effectively utilizing a transmission band.

[0012]

According to the present invention, there is provided a polling method in optical burst communication in which a plurality of subscriber units and a central office unit communicate with each other through an optical fiber via an optical coupler. The polling order of the optical burst signals is changed based on the optical intensity of the optical burst signals so that the optical intensity difference between the optical burst signals is reduced. A polling method in optical burst communication in which a plurality of subscriber units and a central office device communicate with each other through an optical fiber via an optical coupler, wherein a polling method between the optical burst signals is performed based on a distance measurement result of the optical burst signals. The polling order of the optical burst signal is changed so that the light intensity difference is reduced. It is preferable that the polling order be ascending order or descending order of the light intensity of the optical burst signal. On the other hand, according to the apparatus of the present invention, in a polling device in optical burst communication in which a plurality of subscriber devices and a central office device communicate with each other via an optical fiber via an optical fiber, an optical burst signal The configuration is provided with means for changing the polling order of the optical burst signal so that the light intensity difference between them is reduced. Further, in a polling device in optical burst communication that communicates a plurality of subscriber devices and office equipment via optical fibers via optical couplers, based on a distance measurement result of an optical burst signal,
The structure is provided with means for changing the polling order of the optical burst signals so that the light intensity difference between the optical burst signals is reduced. In this case, the polling order is preferably the ascending or descending order of the light intensity of the optical burst signal. Also, an optical-electrical converter that receives an optical burst signal and a preset signal, determines a threshold value, and outputs a light burst signal as an electric burst signal, and an electric burst signal and a signal without preset, and outputs a light intensity signal. A distance measuring device to be output, a scheduler that outputs a polling signal by rearranging the order of the light intensity difference according to the polling setting number signal and the light intensity signal from the band setting device, and a polling signal and a signal without preset as input. And a preset generator that outputs a preset signal after a fixed delay when a preset is required. Also, an optical burst signal and a preset signal are input, a photoelectric converter that determines a threshold value and outputs a light burst signal as an electric burst signal and a light intensity signal, and an electric burst signal and a signal without preset are input, A distance measuring device that outputs a distance measurement value signal, and a polling setting number signal, a light intensity signal, and a distance measurement value signal from a band setting device are input, and the light intensity difference between burst signals is arranged according to the light intensity signal. Alternatively, it may be configured to include a scheduler that outputs a polling signal and a preset generator that receives a polling signal and a signal without a preset and outputs a preset signal after a fixed delay when a preset is required. The scheduler may have a function of outputting a no-preset signal to the distance measuring device and the preset generator when the light intensity of the burst signal is low in the scheduling.

In the present invention, the polling order is changed by the scheduler using the light intensity value and the distance measurement converted in proportion to the light intensity value. No need to change or preset thresholds. As a result, there is no need to change the threshold value or the preset time, and accordingly, the distance between the optical burst signals is reduced.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a block diagram showing a polling technique in optical burst communication according to Embodiment 1 of the present invention, FIG. 2 is a time chart thereof, FIGS. 3 and 4 are enlarged time charts, and FIG. FIG. 6 is a block diagram showing an embodiment of an optical transmission line system to which the present invention is applied;
FIG. 7 is a timing chart.

(Embodiment 1) First, an optical transmission line system to which the present invention is applied will be described with reference to FIG. 6 and FIG. In the transmission path system shown in FIG.
(70), subscriber device 2 (71), subscriber device 3 (7
2) The subscriber device n (73) and the station building device 81 are configured to perform burst communication via the transmission line 80.

The transmission line 80 has a configuration in which optical fibers are connected in a star shape via a coupler 79. The output burst data 74 of the subscriber unit 1, the output burst data 75 of the subscriber unit 2, and the output burst data of the subscriber unit 3.
According to the path difference when passing through the transmission line 80, the output data 77 of the subscriber device n and the transmission line delay of the subscriber device 1 are indicated by arrows and associated broken lines in FIG. 90, transmission line delay 91 of the subscriber unit 2, transmission line delay 92 of the subscriber unit 3, transmission line delay 9 of the subscriber unit n
The station apparatus 81 is output as the station entering coverst signal 78 through the station 3.
To reach.

The polling method according to the first embodiment has a configuration in which a polling order is scheduled using a distance measurement value proportional to the light intensity. As shown in FIG. It has a device 14, a scheduler 17, a band setting device 20, and a preset generator 22. (Explanation of Operation of First Embodiment) FIGS. 2 to 4 show operation timing charts. The opto-electric converter 12 receives the preset signal 23 as input, determines a threshold value, converts the optical burst signal 11 into an electric signal, and outputs an electric burst signal 13.

The distance measuring device 14 outputs the signal 1 without preset.
5 and an electric burst signal 13 as inputs, and outputs a light intensity signal (distance measurement value signal) 16.

The scheduler 17 receives as input the polling set number signal 18 which is the total number of polls to be polled in a specific period from the band setting unit 20, and outputs the light intensity signal 1
According to No. 6, the polling signal 19 is output after rearranging in order of the smallest intensity difference (for example, rearranging in ascending order). It should be noted that the order may be either descending or random, but in any case, the burst signals are rearranged in the order of the smallest difference in intensity.

The scheduler 17 outputs a no-preset signal 15 when the light intensity is low in the scheduling.

The preset generator 20 receives the polling signal 19 and the no-preset signal 15 as inputs, and outputs a preset signal 23 after a fixed delay when a preset is required.

FIG. 2 shows a pattern of the optical burst signal 11 after the scheduling has been performed. Also,
FIG. 3 is an enlarged view when the presetting is performed after the scheduling of FIG. 2 is performed, and FIG. 4 is an enlarged view when the presetting is not performed. As can be understood from FIG. 4, the transmission path band is widened at a rate of 6 bits of the digital signal for each of the optical burst signals for five of the six optical burst signals. That is, the burst signal can be packed and transmitted.

(Embodiment 2) FIG. 5 shows a polling method according to Embodiment 2 of the present invention. The polling sequence is determined by the distance measurement value proportional to the light intensity from the photoelectric converter 32. This is an example in which scheduling is performed.

The photoelectric converter 32 has a preset signal 43
, The threshold value is determined, and the optical burst signal 31
Is converted into an electric signal, and an electric burst signal 33 is output. The distance measuring device 34 receives the no-preset signal 35 and the electric burst signal 33 and outputs a distance measurement value signal 41.

The scheduler 37 inputs the polling set number signal 38, the light intensity signal 36, and the distance measurement signal 41 from the band setting device 40 in accordance with the light intensity signal 36. The polling signal 39 is output after rearrangement in the order of the smallest intensity difference (for example, rearrangement in ascending order).

The scheduler 37 outputs a no-preset signal 35 when the light intensity is low in the scheduling.

The preset generator 42 receives the polling signal 39 and the non-preset signal 35 as inputs, and outputs a preset signal 43 after a fixed delay to the photoelectric converter 32 when a preset is required.

[0028]

As described above, according to the present invention, the distance between optical burst signals can be reduced, so that the transmission band can be expanded. That is, by generating an event that does not require changing the threshold value by the polling method, time for changing the threshold value or presetting is not required, and the transmission bandwidth can be effectively used accordingly.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a polling technique in optical burst communication according to Embodiment 1 of the present invention.

FIG. 2 is a time chart showing a state after scheduling in burst communication according to Embodiment 1 of the present invention.

FIG. 3 is an enlarged time chart showing a state after presetting in optical burst communication according to Embodiment 1 of the present invention.

FIG. 4 is an enlarged time chart showing a state in which no preset is performed in the optical burst communication according to the first embodiment of the present invention.

FIG. 5 is a block diagram showing a polling technique in optical burst communication according to Embodiment 2 of the present invention.

FIG. 6 is a block diagram of a transmission path system to which the present invention is applied.

FIG. 7 is a timing chart of a transmission path system to which the present invention is applied.

FIG. 8 is a block diagram showing a polling technique in optical burst communication according to a conventional example.

FIG. 9 is a time chart showing a state of an optical burst signal in burst light communication according to a conventional example.

FIG. 10 is an enlarged time chart showing a preset state in optical burst communication according to a conventional example.

[Explanation of symbols]

 Reference Signs List 11 optical burst signal 12 photoelectric converter 13 electric burst signal 14 distance measuring device 15 signal without preset 16 light intensity signal (distance measurement value signal) 17 scheduler 18 polling set number signal 19 polling signal 20 band setting device 22 preset generator Reference Signs List 23 preset signal 31 optical burst signal 32 photoelectric converter 33 electric burst signal 34 distance measuring device 35 no preset signal 36 distance measurement value signal 37 scheduler 38 polling setting number signal 39 polling signal 40 band setting device 41 distance measurement value signal 42 Preset generator 43 Preset signal 51 Optical burst signal 52 Photoelectric converter 58 Polling set number signal 59 Polling signal 60 Band setting device 62 Preset generator 63 Preset signal 70 Subscriber device 1 71 Addition Subscriber device 2 72 Subscriber device 3 73 Subscriber device n 74 Outgoing covert data of subscriber device 1 75 Outgoing covert data of subscriber device 2 76 Outgoing covert data of subscriber device 3 77 of subscriber device n Outgoing covert data 78 Station device input burst data 79 Cover 80 Transmission line 81 Station device 90 Delay indication value of subscriber unit 1 91 Delay indication value of subscriber unit 2 92 Delay indication value of subscriber unit 3 93 Subscriber Delay indication value of device n

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification code FI H04J 14/08

Claims (10)

(57) [Claims] 1. A polling method in optical burst communication in which a plurality of subscriber units and a central office unit communicate with each other through an optical fiber via an optical fiber, wherein the optical burst signals are mutually exchanged based on the light intensity of the optical burst signals. A polling method in optical burst communication, wherein a polling order of optical burst signals is changed so that a difference in light intensity between them is reduced. 2. A polling method in optical burst communication in which a plurality of subscriber units and a central office device communicate with each other through an optical fiber via an optical coupler, wherein the optical burst signal is based on a distance measurement result of the optical burst signal. A polling method in optical burst communication, wherein a polling order of optical burst signals is changed so that a difference in light intensity between the optical burst signals is reduced. 3. The polling method according to claim 1, wherein the polling order is an ascending or descending order of the light intensity of the optical burst signal. 4. A polling device in optical burst communication in which a plurality of subscriber units and a central office device communicate with each other via an optical coupler via an optical fiber, wherein the optical burst signal exchange is performed based on the light intensity of the optical burst signal. A polling device for optical burst communication, comprising: means for changing a polling order of optical burst signals so that a difference in light intensity between the polling signals is reduced. 5. A polling device for optical burst communication in which a plurality of subscriber devices and a central office device communicate with each other via an optical coupler via an optical fiber, wherein the optical burst signal is based on a distance measurement result of the optical burst signal. A polling device for optical burst communication, comprising: means for changing a polling order of optical burst signals so that a difference in light intensity between the polling signals is reduced. 6. The polling apparatus according to claim 4, wherein the polling order is an ascending or descending order of the light intensity of the optical burst signal. 7. An optical-to-electrical converter that receives an optical burst signal and a preset signal, determines a threshold value, and outputs a light burst signal as an electric burst signal, and receives an electric burst signal and a signal without preset as an input. A distance measuring device that outputs an intensity signal, a scheduler that outputs a polling signal by rearranging in the order in which the light intensity difference is reduced according to the polling set number signal and the light intensity signal from the band setting device, and the polling signal and the 7. The polling in optical burst communication according to claim 4, further comprising: a preset generator which receives a signal without preset and outputs a preset signal after a fixed delay when preset is required. apparatus. 8. The scheduling device according to claim 7, wherein the scheduler has a function of outputting a no-preset signal to the distance measuring device and the preset generator when the light intensity of the burst signal is low in the scheduling.
A polling device in the optical burst communication according to the above. 9. An opto-electrical converter which receives an optical burst signal and a preset signal, determines a threshold value, and outputs a light burst signal as an electric burst signal and a light intensity signal, and an electric burst signal and a no preset signal. A distance measuring device that outputs a distance measurement signal as an input, and a polling setting number signal, a light intensity signal, and a distance measurement value signal from a band setting device as inputs, and the light intensity difference between burst signals is small according to the light intensity signal. A scheduler that outputs a polling signal in a rearranged order, and a preset generator that receives the polling signal and the no-preset signal as input and outputs a preset signal after a fixed delay when a preset is required. Claims 4 to 6
A polling device in optical burst communication according to any one of the above. 10. The scheduling device according to claim 9, wherein the scheduler has a function of outputting a no-preset signal to the distance measuring device and the preset generator when the light intensity of the light intensity signal is low in the scheduling.
A polling device in the optical burst communication according to the above.