JP2002344470A - Optical burst transmission/reception control system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To recognize the state of a buffer, memory provided to each slave device and reduce a control time in a band, in a master device without lowering utilization of a band. SOLUTION: An ONU 105 has a plurality of buffer memories 1055a, 1055b, for accumulating input data for each type and maintenance signal insertion parts 1054a, 1054b for inserting a maintenance signal including information classified by data type for identifying each data input to the buffer memories 1055a, 1055b. An OLT 101 has a maintenance signal detecting part 1016, which recognizes the buffer memories 1055a, 1055b associated with a maintenance signal, based on information classified by data kind and outputs the receiving state of an associated maintenance signal and a clear to send control part 1013 for carrying out allocation control of a use band of each ONU 105, based on the receiving state of a maintenance signal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an optical burst in which a plurality of child devices share a transmission medium and a transmission band, and each of the child devices transmits data to the parent device based on band allocation control of the parent device. This is related to a transmission / reception control system. In particular, a band shared by a plurality of child devices by dynamically changing a band used by the child device according to a data amount and a data type to be transmitted by the child device. The present invention relates to an optical burst transmission / reception control system designed to make effective use of.

[0002]

2. Description of the Related Art In an optical burst transmission / reception control system in which a plurality of child devices share a transmission medium and a transmission band and each of the child devices transmits data to the parent device based on band allocation control of the parent device, As a prior art in which a parent device dynamically changes a used band of a child device according to a data amount and a data type, for example, Japanese Patent Application Laid-Open No. 11-26627
There is one disclosed in Japanese Patent Publication No. 7 (JP-A) No. 7. FIG. 6 is a block diagram showing the configuration of this conventional technique. In FIG. 6, 10
Is a parent device, 121 is a downstream trunk fiber, 122 is an upstream trunk fiber, 131 is a downstream optical splitter, 132 is a upstream optical splitter, and 141 (141-a to 141-n).
Is a down branch fiber, and 142 (142-a to 142-
n) is an upstream branch fiber, 15 (15-a to 15-n)
Is a child device. The parent device 10 includes a transmission permission control unit 11
3. Downlink cell assembling section 118, maintenance signal position detecting section 11
9. A maintenance signal generator 120 is provided. The child device 15 includes a transmission permission detection unit 153, a buffer memory 155a,
155b, maintenance signal generation unit 1510, maintenance signal detection unit 1
520, priority control unit 1521, selection control unit 1522, class distribution unit 1523, selection unit 1524, state monitoring unit 15
25 are provided. 156 is user data. The configuration of the child devices 15-b to 15-n is the same as that of the child device 15-a.
Since these are the same as those in FIG.

First, the general operation of the prior art will be described. In the optical burst transmission / reception control system, the parent device 10 transmits a transmission permission signal to the downlink cell assembling unit 118 by the transmission permission control unit 113. The downlink cell assembling section 118 to which the transmission permission signal has been given inserts this into the downlink signal and transmits it to each of the slave devices 15-a to 15-n through the optical splitter 131.

[0004] In each of the slave devices 15, the transmission permission detecting section 153 detects the transmission permission signal inserted in the downlink signal, and determines whether or not the slave device 15 is addressed to itself. If the transmission permission signal is addressed to the own device, the buffer memories 155a and 155
5b or the maintenance signal generator 15
The maintenance signal generated in step 10 is selected by the selection unit 1524 and transmitted as an uplink signal at a predetermined transmission timing. This transmission timing is obtained by receiving a maintenance signal transmitted from the maintenance signal generation unit 120 of the parent device 10 at a constant period (reference timing). The data stored in the buffer memories 155a and 155b are distributed according to the priority of each service by the class distribution unit 1523, and the priority control unit 1521 sequentially reads out the data having the higher priority. .

Next, in the above-mentioned prior art, the child device 15
The operation in which the parent device 10 dynamically changes the used band in accordance with the data amount and the data type will be described. First, in the optical burst transmission / reception control system, the buffer memories 155a and 155b supply the respective stored data amounts to the state monitoring unit 1525. The state monitoring unit 1525 generates the state information of the child device 15 based on the information, and
522. The selection control unit 1522 adjusts the timing at which the selection unit 1524 selects and outputs the maintenance signal in accordance with the child device status information given from the status monitoring unit 1525 based on the reference timing. Here, the child device status information described above includes, for example, a buffer memory 155a,
155b is divided into four types according to the inspection result as to whether or not the data accumulation amount is equal to or greater than a predetermined threshold, and these are defined as states 0 to 3. According to the states 0 to 3, the timing at which the selection unit 1524 outputs the maintenance signal is selected.

[0006] Since the parent device 10 recognizes the reference timing, the above four states 0 to 3 can be identified by the reception timing of the maintenance signal from the child device 15. That is, the amount of accumulated data for each service can be identified. On the basis of the identification result, for example, when the storage amount of the service having the high priority is large, it is possible to perform control such as giving a large amount of transmission permission to the child device 15 in particular.

[0007]

As described above, in the prior art, the parent device is based on the transfer time of the maintenance signal from the child device 15 with respect to the reference timing defined between the parent device 10 and the child device 15. The device 10 recognizes the state of the amount of data stored in the buffer memories 155a and 155b of the child device 15, and band control can be performed based on the amount of data and the type of data using the recognition result.

However, according to such a conventional technique, regardless of the state of the buffer memories 155a and 155b, the slave device 15 transmits at least one of the transmission timings given by the master device 10 every reference timing period. Must always send a maintenance signal. For this reason, the band for transmitting data is reduced by the amount of sending the maintenance signal. The decrease in the band increases as the number of child devices 15 increases.

In the prior art, the number of states of the buffer memory provided in the child device 15 (four in the above example) requires the maintenance signal transmission timing. The parent device 10
In order to check the transmission timing for each child device 15, assuming that the interval at which transmission permission is given to the child device 15 is T and the number of states is N, it takes T × N time to identify the state. This time is the time required for the parent device 10 to control the bandwidth allocation of the child device 15. Therefore, in the optical burst transmission / reception control system, when there is a child device 15 having a small band and a long interval at which transmission permission is given, or when there is a child device 15 having many types of data and a large number of states, The time until the parent device 10 next controls the bandwidth allocation of each child device 15 may be significantly increased. That is, the parent device 10 is
Has to be determined, the control time for the other child devices 15 is correspondingly adjusted even if only one child device 15 has a long time to identify the state. It has to be long.

[0010] In such a situation, for example, when realizing communication in which data generation occurs in bursts, such as data transfer between computers, a relatively large band is reserved in advance, or a computer corresponding to a child device is used. The problem can be solved by increasing the buffer memory. However, in the former case, the bandwidth is wasted when no data is generated. That is, this deviates from the original purpose of dynamically changing the band of the child device and realizing the effective use of the band of the transmission path, and has no meaning at all. On the other hand, in the latter case, data transfer becomes possible by enlarging the buffer memory. However, there is a problem that the transfer delay is increased because the time until the transfer becomes possible is long.

Further, when a data transfer protocol such as TCP (Transmission Control Protocol) generally used in the current computer communication is used to confirm whether or not the data transfer is possible, the bandwidth is limited as described above. When the control time is long, there is also a problem that the protocol limits the data transfer amount, and as a result, the throughput does not increase.

As described above, according to the above-described conventional technique, each slave device 15 has its own buffer memory 155a, 155b.
However, there is a problem that the transmission band is reduced by the amount of notification of the state. The buffer memory 155 in the child device 15
When the storage capacities a and 155b are increased, there is a problem that the data transfer delay increases. Furthermore, T
When a data transfer protocol such as a CP for confirming whether or not data transfer is possible is used, there is a problem that the throughput does not increase.

The present invention has been made in view of the above circumstances, and recognizes the state of a buffer memory provided in each child device without reducing the bandwidth utilization rate, and shortens the bandwidth control time in the parent device. It is an object of the present invention to obtain an optical burst transmission / reception control system that can perform the operation.

[0014]

To achieve the above object, an optical burst transmission / reception control system according to the present invention comprises a plurality of slave devices sharing a transmission medium and a transmission band,
In an optical burst transmission / reception control system in which each of the child devices transmits data to the parent device based on the band allocation control of the parent device, the child device stores a plurality of data for storing input data for each type. Storage means, for data input to the data storage means,
Maintenance signal insertion means for inserting a maintenance signal including data type information for identifying each data storage means at a predetermined constant cycle, and the parent device receives the maintenance signal. A maintenance signal detecting unit that recognizes a data storage unit related to the maintenance signal based on the data type information and outputs a reception status of the maintenance signal related to the recognized data storage unit; Transmission permission control means for controlling the allocation of the use band of each child device based on the reception status of the maintenance signal output from the detection means.

According to the present invention, it is possible to control the use band allocation for each data storage unit based on the reception status of the maintenance signal for each data storage unit inserted at a constant cycle.

The optical burst transmission / reception control system according to the next invention is the optical burst transmission / reception control system according to the above invention, wherein the maintenance signal detecting means is configured to perform the maintenance based on the number of maintenance signals for each data storage means received within a predetermined period set in advance. It is characterized by outputting the reception status of the maintenance signal.

According to the present invention, it is possible to control the allocation of the used band of the child device based on the number of the maintenance signals for each data storage means received within a certain period.

[0018] In the optical burst transmission / reception control system according to the next invention, in the above invention, the maintenance signal detection means outputs a reception status of the maintenance signal based on a reception interval of the maintenance signal for each of the data storage means. It is characterized by the following.

According to the present invention, it is possible to control the allocation of the band used by the child device based on the reception interval of the maintenance signal for each data storage means.

[0020] In the optical burst transmission / reception control system according to the next invention, in the above invention, the transmission permission control means notifies band allocation information to each of the child devices in a format that allows each child device to be distinguished. The child device further includes a data transmission control unit capable of controlling data transmission to the parent device based on the notified band allocation information.

According to the present invention, the band allocation information is provided from the transmission permission control means to the data transmission control means in a format in which the child device can be distinguished.

In the optical burst transmission / reception control system according to the next invention, in the above invention, the data transmission control means performs priority control of data to be transmitted based on an amount of data stored in the data storage means. And read control means for reading data based on the band allocation information from the data storage means in accordance with the control result of the priority control means.

According to the present invention, priority control of data to be transmitted is performed based on the amount of data stored in the data storage unit, and data is read from the data storage unit based on the band allocation information according to the control result.

In the optical burst transmission / reception control system according to the next invention, in the above invention, the master device includes a maintenance signal management unit for notifying the slave device of a maintenance signal insertion cycle to the slave device. The apparatus further comprises an insertion control unit for instructing the maintenance signal insertion unit of a maintenance signal insertion period based on an insertion period notified from the maintenance signal management unit and a control result of the priority control unit. .

According to the present invention, the maintenance signal insertion cycle is determined based on the insertion cycle notified from the maintenance signal management means and the control result of the priority control means.

In the optical burst transmission / reception control system according to the next invention, in the above invention, when the data storage means increases the amount of stored data, the data storage means outputs the next stored output before outputting the maintenance signal. It is characterized by outputting data.

According to the present invention, when the data storage amount is large, the output of the maintenance signal can be omitted.

In the optical burst transmission / reception control system according to the next invention, in the above invention, the band allocation information is use permission information of a time slot defined in a transmission direction from the child device to the parent device. It is characterized by.

According to the present invention, the time slot use permission information defined in the transmission direction from the child device to the parent device is used as the band allocation information.

[0030]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of an optical burst transmission / reception control system according to the present invention will be described below in detail with reference to the accompanying drawings.

Embodiment 1 Embodiment 1 of the present invention
In the prior art, a maintenance signal generator is arranged at a stage preceding a buffer memory divided for each type of data, and a maintenance signal is periodically inserted into data input to each buffer memory. is there. Each maintenance signal is provided with an identifier capable of distinguishing a data type or a buffer memory.

FIG. 1 is a block diagram showing a configuration of an optical burst transmission / reception control system according to Embodiment 1 of the present invention. The optical burst transmission / reception control system exemplified here is, for example, an ITU-T (International Telecommunication).
Recommendation Union-Telecommunicationsector) 98
3.1 (Broadband optical access systems based on
ATM-PON (Asynchronous Transfer Mode) defined in Passive Optical Networks (PON) 1998/10)
Passive Optical Networks)
T (Optical Line Termination) and multiple (n) O
This is a configuration for realizing communication with an NU (Optical Network Unit). In this recommendation, a transmission format as shown in FIG. 2 is used. The transmission data has a fixed length of 53 bytes in the downstream direction and 56 bytes in the upstream direction. The slot position where each ONU outputs data to the uplink transmission path is specified by the OLT. Specifically, in FIG. 2, PLOAM (Physic
al Layer Operation Administration and Maintenanc
e) A slot position for outputting data is notified using a management signal called a cell. The format of this PLOAM cell is as shown in FIG. However, FIG. 3 shows only 48 bytes in which 53 bytes of the ATM header portion are omitted from 53 bytes. The transmission permission of each slot in the uplink direction from the OLT to the ONU is represented by GR
This is notified by a transmission permission identifier called ANT.
GRANT is GRANT1 to GRANT in FIG.
27. Numbers 1 to 27 indicate the time slot positions in the uplink direction. Each ONU receives from the OLT a transmission identifier previously assigned to itself. After that, when the PLOAM cell is received, G
If the assigned transmission identifiers are assigned to RANT1 to GRANT27, data can be transmitted in the corresponding time slot.

In FIG. 1, 101 is an OLT, 102 is a trunk fiber, 103 is an optical splitter functioning as a multiplexer / demultiplexer for optical burst signals, and 104 (104-a to 104-104).
-N) is a branch fiber, 105 (105-a to 105-)
n) is an ONU. In the first embodiment, the OLT 1
01 corresponds to the parent device, and ONU 105 corresponds to the child device. In the OLT 101, 1011 is an optical transceiver, 1
012 is a management signal insertion unit, 1013 is a transmission permission control unit,
1014 is a code allocation unit, 1015 is a service management unit,
Reference numeral 1016 denotes a maintenance signal detection unit. Also, ONU105
, 1051 is an optical transceiver, 1052 is a management signal extraction unit, 1053 is a transmission permission detection unit, 1054a and 1054a.
54b is a maintenance signal insertion unit, 1055a and 1055b are buffer memories, 1056a and 1056b are user data, 1057 is a multiplexing unit, 1058 is a read control unit, 105
9 is a priority control unit, and 10510 is a code identification unit. The configuration of the ONUs 105-b to 105-n is
Since it is the same as NU105-a, illustration and description of each are omitted.

The operation of the optical burst transmission / reception control system will be described below. First, in the OLT 101, the service management unit 1015 checks each ONU 105-
The codes as transmission permission identifiers of the data input to a to 105-n are associated with different values for each of the ONUs 105-a to 105-n, and the corresponding information is assigned to a code allocating unit 1014.
Send to The code allocating unit 1014 includes the ONUs 105-a to
A code as a transmission permission identifier is determined in advance for each 105-n, and the value is sent to the management signal insertion unit 1012. The management signal insertion unit 1012 sets the transmitted transmission permission identifier to O.
The management signal is included in the management signal in a format that can be identified for each of the NUs 105-a to 105-n, and the management signal is transmitted to the optical transceiver 1011. Here, the management signal indicates which ONU 105-a to 105
Whether or not a transmission permission identifier addressed to -n is included can be identified by notifying a predetermined number of ONUs 105-a to 105-n and a transmission permission identifier as a set. The optical transceiver 1011 converts the transmitted management signal into an optical signal and transmits the optical signal to the trunk fiber 102. The transmitted optical signal is distributed to the branch fibers 104-a to 104-n in the optical splitter 103, and the ONUs 105-a to O connected respectively.
It is sent to the NU 105-n.

Each of the ONUs 105-a to 105- supplied with an optical signal through the branch fibers 104-a to 104-n.
In n, the optical transceiver 1051 converts the optical signal into an electric signal, and sends the electric signal to the management signal extracting unit 1052 and the inside. The management signal extraction unit 1052 extracts a management signal from the electric signal, and supplies the management signal to the code identification unit 10510, the transmission permission detection unit 1053, and the priority control unit 1059. The code identification unit 10510 to which the management signal has been given extracts the transmission permission identifier associated with the predetermined ONU number from the management signal, stores it, and stores the value in the read control unit 1058. send.

Next, the transmission permission control unit 10 of the OLT 101
Reference numeral 13 designates a predetermined transmission permission identifier for each of the various data at a frequency corresponding to the band required by the various data of the ONUs 105-a to 105-n. And sends it to the management signal insertion unit 1012. Management signal insertion unit 1
Thereafter, the ONU 105 transmits the management signal to each ONU 105 in the same procedure as when the code is transmitted.
-A to 105-n. Here, ONU105-
The bands required by the data a to 105-n are set, for example, as follows. That is, for a data type that requires a constant band continuously, a value corresponding to the band is set. On the other hand, for data types in which transfer data is generated intermittently or the transfer data amount changes with time, a value smaller than the bandwidth required at the peak of the data transfer amount is set. Keep it.

Each ONU 105-a to which the management signal is given
In ~ 105n, the transmission permission detecting unit 1053 detects the transmission permission identifier inserted in the management signal, and notifies the read control unit 1058 of the detection. The read control unit 1058 checks the value of the assigned area of each slot provided from the transmission permission detection unit 1053, and the check result indicates that the code identification unit 10510
If the code matches the code notified from, an attempt is made to read data from the buffer memories 1055a and 1055b in the upstream time slot corresponding to the slot in which the match was detected. Buffer memory 1055a, 1
If there is no data to be read when a read request is received from the read control unit 1058, 055b generates empty data and sends it to the multiplexing unit 1057. The transmitted data is multiplexed by the multiplexing unit 1057, and the optical transceiver 1
051. Data passing through the optical transceiver 1051 is transmitted from the branch fibers 104-a to 104-n to the OLT 101 through the optical splitter 103 and the trunk fiber 102.
Is transmitted to

If data exists in both of the buffer memories 1055a and 1055b, it is determined from which data is to be read according to the following procedure. First, priority information corresponding to the type of data stored in each of the buffer memories 1055a and 1055b is notified to the priority control unit 1059 via the management signal extraction unit 1052 using the management signal from the OLT 101. The buffer memories 1055a and 1055b notify the priority control unit 1059 of the respective data storage amounts. Priority control unit 10
59 selects the buffer memories 1055a and 1055b from which data is read based on the priority information notified from the OLT 101 and the data storage amounts notified from the buffer memories 1055a and 1055b, and notifies the read control unit 1058 of the selection result. I do. For example, when there is a difference between the priorities notified from the OLT 101, the buffer memory with the higher priority is selected, and when the priorities are equal, the buffer memory with the larger data storage amount is selected. .

Maintenance signal insertion units 1054a and 1054b
Are stored in the buffer memory 1055 at predetermined intervals.
A maintenance signal with an identifier capable of distinguishing between the buffer memories 1055a and 1055b is inserted into the data input to the data a and 1055b. The format of the maintenance signal is, for example, the buffer memories 1055a and 1055b.
When there is no data to be read into the buffer memory 105,
The identifier may be added to a part of the free data generated by 5a and 1055b. Further, this empty data is stored in ITU-T Recommendation I. The maintenance signal may be an idle cell (IDLE CELL) defined by 432, and the maintenance signal may be one in which the above-mentioned identifier is added to its payload (a part excluding the ATM header).

In the OLT 101, the maintenance signal detecting unit 10
Reference numeral 16 extracts a maintenance signal included in the upstream signal transmitted from each of the ONUs 105-a to 105-n, and constantly monitors the identifiers of the buffer memories 1055a and 1055b provided therein. Further, the number of times of receiving the maintenance signal including the identifier related to each of the buffer memories 1055a and 1055b is counted within a predetermined period, and the count result is notified to the transmission permission control unit 1013.
The transmission permission control unit 1013 controls each of the ONUs 105-a to
For the 5-n buffer memories 1055a and 1055b, the number of permitted transmissions currently allocated during the above-described fixed period is compared with the number of times the maintenance signal is received. If the number of times of reception is smaller than the number of permitted transmissions allocated during a certain period, the ONU 105-having the buffer memories 1055 a and 1055 b having the smaller ratio.
Control is performed so that a large number of transmission permissions are assigned to a to 105-n.

FIG. 4 shows that the input data of the ONU 105 is OL.
This figure shows the data transmission timing up to the maintenance signal detection unit 1016 in T101, where (a) is a diagram when the input data is large and (b) is a diagram when the input data is small. As is apparent from these figures, although the maintenance signals are inserted at regular intervals To from the maintenance signal insertion units 1054a and 1054b for the input data, the maintenance signals are inserted between the maintenance signals depending on the amount of input data. Therefore, even if the transmission permission given by the OLT 101 is under the same condition, the number of receptions of the maintenance signal existing in the monitoring period Tm when transmitted to the OLT 101 is different from each other. Become. For example, if the input data is large, the number of data between the maintenance signals also increases,
When transmitted to the OLT 101, the number of receptions of the maintenance signal existing during the monitoring cycle Tm is smaller than when the input data is small. Therefore, when the amount of input data increases, the transmission permission control unit 1013 of the OLT 101 performs control so as to allocate more transmission permission. Conversely, when the input data is reduced, the monitoring cycle Tm
Since the number of times the maintenance signal existing in the
The transmission permission control unit 1013 of T101 performs control so as to allocate a small number of transmission permissions. As a result, it is possible to dynamically control the bandwidth in accordance with the increase or decrease of the input data input to the ONU 105.

Here, it is important to count the number of times the maintenance signal is received in relation to each of the buffer memories 1055a and 1055b in a certain period. That is, by counting the number of times the maintenance signal including the identifier associated with each of the buffer memories 1055a and 1055b is received, the accumulation status of the data can be known for each of the buffer memories 1055a and 1055b. Therefore, a plurality of buffer memories 1
Band control can be performed even when the storage amount of one of 055a and 1055b is large. Also, by counting the number of times the maintenance signal is received during a certain period, the control time of the band becomes constant. The predetermined period for counting the number of times the maintenance signal is received may be set in accordance with the transmission permission interval corresponding to the minimum bandwidth of each data. That is, if a certain period for counting the number of times the maintenance signal is received is set in accordance with the transmission permission interval corresponding to the minimum bandwidth of data, reading from the corresponding buffer memories 1055a and 1055b is performed once during the set certain period. Therefore, it is possible to determine whether or not data is input to the buffer memories 1055a and 1055b based on at least whether or not the signal is a maintenance signal.

Further, a plurality of buffer memories 1055a,
When data of different priorities are stored in the 1055b, even if the storage amount of low-priority data is large and the number of permitted transmissions increases, the ONUs 105-a to 105-
As long as high-priority data exists, the n-th priority control unit 1059 reads data from the high-priority data, and reads low-priority data when the high-priority data no longer exists. Therefore, low-priority data can be transferred without affecting the transfer of high-priority data.

Further, a plurality of buffer memories 1055
When the data of the same priority is stored in the ONUs 105-a to 105-n, the priority control units 10 of the ONUs 105-a to 105-n are stored.
Reference numeral 59 denotes a buffer memory 1055 having a large data storage amount.
Since the reading is performed preferentially from a and 1055b, the band can be used more efficiently.

In addition, although the maintenance signal is inserted at a constant cycle, when the input data increases and a larger transmission band is required, the bandwidth used for the maintenance signal becomes relatively small. In other words, unlike the related art, a fixed band is not always occupied in any state, so that the band can be used efficiently.

As described above, according to the optical burst transmission / reception control system of the first embodiment, dynamic bandwidth control in consideration of the priority of data and the amount of data stored in each of the buffer memories 1055a and 1055b can efficiently control the bandwidth. And a short feedback time. As a result, buffer memories 1055a, 1
055b can be suppressed, and the throughput of TCP protocol data can be improved.

In the first embodiment described above, the maintenance signal detection unit 1016 notifies the transmission permission control unit 1013 of the number of maintenance signals for each of the buffer memories 1055a and 1055b received during a fixed period as a reception status. However, the reception interval of the maintenance signal for each of the buffer memories 1055a and 1055b may be notified as the reception status. That is, if the reception interval of the maintenance signal is wide, the transmission permission control unit 1013 can recognize that the input data is large, while if the reception interval of the maintenance signal is short, the transmission permission control unit 1013 can recognize that the input data is small. , It is possible to dynamically control the band based on these. Also in this case, maintenance signal insertion section 1054
Since the period of the maintenance signal inserted by a and 1054b is constant, there is no possibility that the time required for the band allocation control becomes extremely long.

Embodiment 2 In the second embodiment, in the optical burst transmission / reception control system of the first embodiment, the maintenance signal insertion cycle can be notified from the OLT, and if the data storage amount increases, the maintenance signal insertion rate is reduced. It was done.

FIG. 5 is a block diagram showing a configuration of an optical burst transmission / reception control system according to the second embodiment of the present invention. In FIG. 5, the OLT 101 is provided with a maintenance signal management unit 1017, but the configuration of each unit is the same as that of the first embodiment. The operation of each unit excluding the service management unit 1015, the management signal insertion unit 1012, and the transmission permission control unit 1013 is the same as that of the first embodiment. On the other hand, as for the ONU 105, although an insertion control unit 10511 is newly provided, the configuration of other units is the same as that of the first embodiment. The maintenance signal insertion units 1054a and 1054b, the buffer memory 105
The operation of each unit except 5a, 1055b and the priority control unit 1059 is the same as that of the first embodiment. In addition, ONU
The configuration of the ONU 105-b to the ONU 105-n
Since this is the same as -a, illustration and description of each are omitted.

Hereinafter, the operation of the OLT 101 and the ONU 105 that are different from the first embodiment will be described. First, in the OLT 101, the service management unit 101
5 is the same as the operation in the first embodiment, and each ONU 105-
The service type information of the data input to a to 105-n is notified to the maintenance signal management unit 1017. The transmission permission control unit 1013 includes, in addition to the operation in the first embodiment,
It notifies the maintenance signal management unit 1017 of the allocated band information of 05-a to 105-n. The maintenance signal management unit 1017
The maintenance signal insertion cycle for each of the buffer memories 1055a and 1055b of each of the ONUs 105-a to 105-n is set based on the allocated bandwidth information given from the transmission permission control unit 1013. Further, the maintenance signal management unit 1017
Based on the service type information provided from the service management unit 1015, it is determined whether or not it is necessary to dynamically control the bandwidth. If it is determined that the service type does not need to be dynamically controlled, a maintenance signal Make settings to prohibit insertion.
The setting information on the maintenance signal insertion cycle and whether or not the maintenance signal can be inserted is sent from the maintenance signal management unit 1017 to the management signal insertion unit 1012. The management signal insertion unit 1012 includes the maintenance signal management unit 1017 in addition to the operation in the first embodiment.
The management information includes the setting information given by the user and transmitted.

On the other hand, in the ONUs 105-a to 105-n, the buffer memories 1055a and 1055b monitor whether or not the next data to be read is a maintenance signal, in addition to the operation of the first embodiment. When the data storage amount is large, the next data is output earlier without outputting the maintenance signal. The priority control unit 1059 includes the buffer memories 1055a and 1055a, 1
055b inserts information related to the data storage amount
0511 is notified. The OLT 10511
A maintenance signal insertion cycle included in the management signal from 101;
Alternatively, it extracts the setting information of whether or not the maintenance signal can be inserted, and instructs each of the maintenance signal insertion units 1054a and 1054b on the insertion cycle according to the extracted information. Further, the insertion control unit 10511
Is based on the information related to the data storage amount from the priority control unit 1059, and
A change is made so as to lengthen the insertion cycle for 55a and 1055b, and a similar instruction is issued. Maintenance signal insertion unit 105
4a and 1054b insert the maintenance signal in the same manner as in the first embodiment, but the insertion cycle is the insertion control unit 10511.
Follow the instructions from Further, when there is an instruction to prohibit insertion from the insertion control unit 10511, the maintenance signal insertion unit 1054
Neither a nor 1054b insert a maintenance signal.

When the above operation is performed, the difference from the first embodiment is as follows. First, since the maintenance signal insertion cycle is set in accordance with the allocated band of the transmission permission identifier unit for each data type, the maintenance signal reception frequency monitoring cycle Tm is also set to each ONU 105-a to 105-n at that time.
The use of a maintenance signal that minimizes the waste of the transmission band enables band control in a short control time.

Next, the buffer memories 1055a and 1055
5b, the maintenance signal insertion cycle is controlled in accordance with the data storage amount. If the data storage amount is large, the maintenance signal already stored is also deleted to give priority to data transmission.
When the increase in the data amount is very large, the maintenance signal can be used for the data transfer band.

Furthermore, since no maintenance signal is inserted for data that does not require dynamic bandwidth control depending on the type of service, unnecessary maintenance signal bandwidth and processing can be omitted.

Therefore, according to the second embodiment, similarly to the first embodiment, the priority of data and the buffer memory 1
Dynamic bandwidth control in consideration of the data storage amount for each of 055a and 1055b is possible with a short feedback time while efficiently using the bandwidth. As a result, it is possible to suppress an increase in the data storage buffer memories 1055a and 1055b, and to improve the throughput of TCP protocol data. Further, it is possible to improve the efficiency of the transmission band. Further, band control in a short time can be realized. Furthermore, by preventing the maintenance signal from being inserted into a service that does not require dynamic band control, it is possible to further effectively use the band and simplify the processing.

[0056]

As described above, according to the present invention, based on the reception status of the maintenance signal for each data storage unit inserted at a fixed period, the allocation of the used band is controlled for each data storage unit. Therefore, dynamic bandwidth control becomes possible. In addition, since the maintenance signal is inserted at a constant cycle, the data increases, and when a larger transmission band is required, the bandwidth used for the maintenance signal becomes relatively small. Therefore, it is possible to use the band efficiently.

According to the next invention, it is possible to control the allocation of the bandwidth used by the child device based on the number of maintenance signals for each data storage means received within a certain period. Even if there is a child device that has a long permission interval or a child device that has many types of data and a large number of states, the bandwidth control time is constant, and the parent device becomes the next child device. There is no danger that the time until the control of the band allocation of the device is significantly increased. As a result, there is no need to increase the capacity of the data storage means, and the throughput of TCP protocol data can be improved.

According to the next invention, it is possible to control the allocation of the use band of the child device based on the reception interval of the maintenance signal for each data storage means. Even if there is a long child device or a child device with many types of data and a large number of states, the bandwidth control time is constant, and the parent device controls the bandwidth allocation of the child device next. There is no fear that a situation in which the time required to perform the operation becomes extremely long will be caused.
As a result, there is no need to increase the capacity of the data storage means, and the throughput of TCP protocol data can be improved.

According to the next invention, band allocation information is provided from the transmission permission control means to the data transmission control means in a format in which the child apparatus can be distinguished. Transmission can be controlled.

According to the next invention, priority control of data to be transmitted is performed based on the amount of data stored in the data storage unit, and data is read from the data storage unit based on the band allocation information in accordance with the control result. Therefore, band control can be performed in consideration of the priority and the storage amount of data.

According to the next invention, the maintenance signal insertion cycle is determined based on the insertion cycle notified from the maintenance signal management means and the control result of the priority control means. Optimum band control using is possible.

According to the next invention, when the amount of stored data is large, the output of the maintenance signal can be omitted. Therefore, when the increase in the data amount is very large, the use band of the omitted maintenance signal is reduced. It can be used as a transfer band.

According to the next invention, the use permission information of the time slot defined in the transmission direction from the child device to the parent device is used as the band allocation information. Can be transmitted.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of an optical burst transmission / reception control system according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a data transmission format used in the first embodiment.

FIG. 3 is a diagram showing a format of a PLOAM cell which is a management signal.

FIG. 4 is a diagram showing data transmission timing until input data of a child device reaches a parent device.

FIG. 5 is a block diagram illustrating a configuration of an optical burst transmission / reception control system according to a second embodiment of the present invention;

FIG. 6 is a block diagram showing a configuration of a conventional technique.

[Explanation of symbols]

Reference numerals 101 OLT, 105 ONU, 1011 optical transceiver, 1012 management signal insertion unit, 1013 transmission permission control unit, 1014 code allocation unit, 1015 service management unit, 1016 maintenance signal detection unit, 1017 maintenance signal management unit, 102 trunk fiber, 103 Optical splitter,
104 branch fiber, 1051 optical transceiver, 105
10 code identification unit, 10511 insertion control unit, 105
2 management signal extraction unit, 1053 transmission permission detection unit, 10
54a, 1054b Maintenance signal insertion unit, 1055a, 1
055b buffer memory, 1057 multiplexer, 105
8 Read control unit, 1059 Priority control unit.

 ──────────────────────────────────────────────────の Continued on the front page F term (reference) 5K002 AA01 AA03 BA04 DA03 DA05 DA12 FA01 5K033 AA01 CA12 CA17 CB06 CC01 DA01 DA15 DB02 DB05 DB13 DB17 EA06 EA07 EC01

Claims (8)

[Claims] 1. An optical burst transmission / reception control system in which a plurality of child devices share a transmission medium and a transmission band, and each of the child devices transmits data to the parent device based on a band allocation control of the parent device. A plurality of data storage means for storing input data for each type, and data type information for identifying each data storage means for the data input to the data storage means. And a maintenance signal insertion unit that inserts a maintenance signal including the maintenance signal at a predetermined constant cycle, and wherein, when the maintenance signal is given, the parent device transmits the maintenance signal to the maintenance signal based on the data type information. A maintenance signal detecting means for recognizing the related data storage means and outputting a reception status of the maintenance signal related to the recognized data storage means; An optical burst transmission / reception control system, comprising: transmission permission control means for performing allocation control of the use band of each child device based on the reception status of the maintenance signal output from the signal detection means. 2. The maintenance signal detection unit outputs a maintenance signal reception status based on the number of maintenance signals for each data storage unit received within a predetermined period set in advance. 2. The optical burst transmission / reception control system according to 1. 3. The optical burst transmission / reception control according to claim 1, wherein the maintenance signal detection unit outputs a maintenance signal reception status based on a maintenance signal reception interval for each of the data storage units. system. 4. The transmission permission control means notifies band allocation information to each of the child devices in a format in which each of the child devices can be distinguished, and the child device transmits the band allocation information based on the notified band allocation information. The optical burst transmission / reception control system according to any one of claims 1 to 3, further comprising a data transmission control unit capable of controlling data transmission to the parent device. 5. The data transmission control means, wherein: priority control means for performing priority control of data to be transmitted based on an amount of data stored in the data storage means; and the data storage means according to a control result of the priority control means. The optical burst transmission / reception control system according to any one of claims 1 to 4, further comprising: read control means for reading data based on the band allocation information. 6. The master device further comprises maintenance signal management means for notifying the child device of an insertion cycle of the maintenance signal. 2. An apparatus according to claim 1, further comprising an insertion control unit for instructing the maintenance signal insertion unit on a maintenance signal insertion cycle based on a control result of the priority control unit.
5. The optical burst transmission / reception control system according to any one of 5. 7. The data storage device according to claim 1, wherein the data storage means outputs the next output data stored before the maintenance signal is output, when the storage amount of the data increases. An optical burst transmission / reception control system according to any one of the preceding claims. 8. The apparatus according to claim 1, wherein the bandwidth allocation information is use permission information of a time slot defined in a transmission direction from the child device to the parent device. An optical burst transmission / reception control system as described in the above.