JP6219809B2 - BAND ALLOCATION DEVICE, BAND ALLOCATION METHOD, AND BAND ALLOCATION PROGRAM - Google Patents

Description

  The present invention relates to a bandwidth allocation technique for a communication device in a communication station used for commercial purposes, and in particular, a bandwidth allocation device, a bandwidth allocation method, and a processing program for performing bandwidth allocation processing for bandwidth allocation of a laid communication device. The present invention relates to a machine-readable recording medium on which is recorded.

  A bandwidth allocation method for communication apparatuses has been proposed (see, for example, Patent Document 1). In the dynamic bandwidth allocation method of Patent Document 1, a communication device functioning as an optical terminal device (OLT) is operated by an optical subscriber unit (ONU: Optical Network Unit) that is an allocation destination device. To assign. At this time, the OLT allocates a “predicted” band to a distant ONU that cannot notify the transmission permission for the transmission request within the predetermined time, and is close enough to notify the transmission permission for the transmission request within the predetermined time. Allocate the remaining bandwidth to the ONU.

  Patent Document 1 does not clarify a method for predicting a bandwidth for a remote ONU. Further, since Patent Document 1 does not exceed the prediction range, there is a problem that if the prediction is lost, the delay time becomes large and the service quality deteriorates.

  In the MPCP (Multi Point-Control Protocol) sequence used for bandwidth allocation of communication apparatuses, there are a Discovery process and an OLT-ONU communication process. In the Discovery process, when upstream communication is performed, the upstream signal of each ONU collides by exchanging the transmission start time (Grant Start time) and the transmission time (Grant Length) between each ONU and the OLT in advance. Bandwidth allocation that does not occur is realized. Here, the transmission start time indicates the transmission timing, and the transmission time indicates the transmission permission amount. In the OLT to ONU communication process, the ONU performs upstream communication to the OLT at the transmission start time (Grant Start time) and the transmission time (Grant Length) permitted in the Discovery process. These processes are performed at every DBA (Dynamic Bandwidth Allocation) cycle that is an allocation cycle.

In the communication apparatus having the above configuration, there is a method using delay time and bandwidth utilization efficiency as a method for improving the quality of service.
The delay time is the time from when the allocation destination device requests the transmission request amount data requested by the allocation destination device until the transmission is completed. For example, the ONU transmits the transmission request amount to the OLT in a certain DBA cycle. In this case, the total amount of time required until the transmission request amount data is transmitted to the OLT. This is the total time required for transmission in the OLT-ONU communication process in the next DBA cycle when a difference occurs between the requested bandwidth of the ONU and the transmittable bandwidth of the OLT in the OLT-ONU communication process. When the DBA cycle time is shortened, the delay time is shortened because the time until the next DBA cycle is shortened. As the delay time of each ONU is shorter, data necessary as a service can be transmitted without delay. From the viewpoint of the delay time, the service quality is improved by shortening the DBA cycle time.
Bandwidth utilization efficiency is the ratio of pure data transmission time to DBA cycle time. In the bandwidth allocation method by DBA, since the upstream signal is sent through the Discovery process and the OLT-ONU communication process, not only pure data transmission such as processing of the report (Report) signal in all bands, but also the ONU of each ONU There is a bandwidth for a prior confirmation process so that upstream signals do not collide. If the DBA cycle time is increased, the frequency of the prior confirmation process is reduced, so that the bandwidth utilization efficiency is improved. Since the higher the ratio of pure data in one DBA cycle, the more necessary data can be sent. From the viewpoint of bandwidth utilization efficiency, the service quality increases with the DBA cycle time.

JP2011-234242A

  In dynamic bandwidth allocation in a communication device, in order to reduce the delay time during communication with a user (ONU), it is possible to reduce the delay time by reducing the DBA cycle time between the communication device and each ONU. is there. However, if the DBA cycle time is reduced, the bandwidth utilization efficiency will decrease.

  On the other hand, in order to further improve the bandwidth utilization efficiency during communication with the user (ONU), it is possible to increase the bandwidth utilization efficiency by increasing the DBA cycle time between the communication device and each ONU. However, increasing the DBA cycle time will increase the delay time.

  In this way, an object is to set an optimal DBA cycle time that takes into account the trade-off relationship between the delay time and the bandwidth utilization efficiency, taking into account the trade-off variable between the delay time and the bandwidth utilization efficiency in the DBA cycle time. And

  The present invention calculates the delay time and bandwidth utilization efficiency of each ONU using the DBA cycle time as a parameter when the communication apparatus assigns the bandwidth to each ONU, and the delay time obtained with respect to the DBA cycle time The optimal DBA cycle time is determined using the relative relationship of the bandwidth utilization efficiency.

  Specifically, the bandwidth allocating device according to the present invention includes a delay time which is a time from when the allocation destination device requests the transmission request amount data requested by the allocation destination device to completion of transmission and an existing allocation cycle. The bandwidth utilization efficiency, which is the ratio of the transmission time of the requested transmission data to the time, is calculated using the allocation cycle time as a parameter, and the allocation cycle time is calculated using the relative relationship between the obtained delay time and the bandwidth utilization efficiency. A bandwidth allocation unit that determines and allocates a bandwidth to the allocation destination device using the determined allocation cycle time is provided.

  In the bandwidth allocation device according to the present invention, the bandwidth allocation unit normalizes the reciprocal of the delay time and the bandwidth utilization efficiency so that the sum of squares of the normalized delay time and the reciprocal of the bandwidth utilization efficiency is minimized. The allocation cycle time may be determined.

  In the bandwidth allocating device according to the present invention, the bandwidth allocating unit may normalize the delay time and the bandwidth utilization efficiency within a range where the delay time and the bandwidth utilization efficiency are not less than 0 and less than the existing allocation cycle time. Good.

  In the bandwidth allocating device according to the present invention, a transmission permission amount determined by the bandwidth allocating unit, which is connected to a plurality of the allocation destination devices through an optical transmission line, receives a report signal including the transmission request amount from the allocation destination device, and And a transmission / reception unit that transmits a gate signal including transmission timing to the allocation destination device, wherein the band allocation unit uses the existing allocation cycle time of the allocation destination device and the transmission delay time of the allocation destination device. A delay time is calculated, the bandwidth usage efficiency is calculated using an existing allocation cycle time of the allocation destination device and a transmission time of the report signal from the allocation destination device, and a relative value of the delay time and the bandwidth usage efficiency is calculated. A transmission permission amount and a transmission timing are determined for the allocation destination device using the allocation cycle time determined using the relationship so that signals from the plurality of allocation destination devices do not collide with each other. It may be allocated bandwidth by.

  Specifically, in the bandwidth allocation method according to the present invention, a delay time that is a time from when the allocation destination device requests the transmission request amount data requested by the allocation destination device to completion of transmission and an existing allocation cycle The bandwidth utilization efficiency, which is the ratio of the transmission time of the requested transmission data to the time, is calculated using the allocation cycle time as a parameter, and the allocation cycle time is calculated using the relative relationship between the obtained delay time and the bandwidth utilization efficiency. An allocation cycle time determination procedure to be determined and a bandwidth allocation procedure to allocate a bandwidth to the allocation destination device using the determined allocation cycle time are sequentially provided.

  In the bandwidth allocation method according to the present invention, in the allocation cycle time determination procedure, the bandwidth allocation unit normalizes the reciprocal of the delay time and the bandwidth utilization efficiency, and calculates the normalized delay time and the reciprocal of the bandwidth utilization efficiency. The allocation cycle time may be determined so that the sum of squares is minimized.

  In the bandwidth allocation method according to the present invention, in the allocation cycle time determination procedure, the delay time and the bandwidth usage efficiency are normalized within a range that is equal to or less than an existing allocation cycle time and the delay time and the bandwidth usage efficiency are 0 or more. May be.

  Specifically, the bandwidth allocation program according to the present invention is a program for causing a computer to execute the allocation cycle time determination procedure and the bandwidth allocation procedure according to the present invention.

  The above inventions can be combined as much as possible.

  According to the present invention, it is possible to set an optimal DBA cycle time that achieves both trade-off delay time and bandwidth utilization efficiency.

An example of the delay time when the number of ONUs is changed is shown. An example of bandwidth utilization efficiency when the number of ONUs is changed is shown. 1 shows an example of a bandwidth allocation system according to an embodiment of the present invention. The structural example of the communication apparatus 92 is shown. 2 shows an example of a bandwidth allocation method according to an embodiment of the present invention. The specific example of information acquisition procedure S301 is shown. A specific example of the delay time adaptive range calculation procedure S302 for each DBA cycle time is shown. A specific example of the bandwidth use efficiency adaptive range calculation procedure S303 for each DBA cycle time is shown. The specific example of distance calculation procedure S304 is shown. A specific example of the DBA cycle time setting procedure S305 will be described. An example of characteristics of delay time and bandwidth utilization efficiency when providing a communication service is shown. An example of characteristics of delay time and bandwidth utilization efficiency is shown. The enlarged view of the setting range of the delay time and band utilization efficiency obtained by restrictions 1-4 is shown. An example of the coordinate point of the delay time after normalization and band utilization efficiency (reciprocal number) is shown. An example of DBA cycle time when the number of ONUs is changed is shown. An example of dispersion | distribution of the distance from the target point in each ONU number is shown.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, this invention is not limited to embodiment shown below. These embodiments are merely examples, and the present invention can be implemented in various modifications and improvements based on the knowledge of those skilled in the art. In the present specification and drawings, the same reference numerals denote the same components.

  The allocation cycle time of the Discovery process and the OLT-ONU communication process per unit time is shortened, and the number of bandwidth allocations is increased. As a result, ONU transmission waiting data can be transmitted efficiently, so that the amount of delay during communication can be reduced. However, there is a trade-off relationship described below between the delay time for each DBA cycle time and the bandwidth utilization efficiency.

FIG. 1 shows an example of the delay time when the number of ONUs is changed. The delay time T _D of the vertical axis, if ONU91 sends required in certain DBA cycle is the total time to ONU91 has completed transmitting the data transmission demand from the transmission request. The delay time T _D (ns) is the sum of the DBA cycle time T _DBA (μs) per unit time and the transmission delay time T _T (μs). If ONU91 that requested the transmission demand in certain DBA cycle has completed the transmission of the data of the transmission request amount in the next DBA period, the delay time T _D is expressed by the following equation.
(Equation 1)
T _D = (T _DBA × 2 + T _T ) × 1000 (1)

Transmission delay time T _T is the time required for data transmission and reception, and is represented by, for example, below.
(Equation 2)
T _T = S _ONU × D _ONU × 2 (2)
Here, S _ONU is the time per unit distance required for transmission between the _ONU 91 and the communication device 92, and is, for example, 5 μs / km. D _ONU (km) is an average distance from the communication device 92 to the _ONU 91.

FIG. 2 shows an example of bandwidth utilization efficiency when the number of ONUs is changed. The band use efficiency E _B (%) on the vertical axis is the ratio of the transmission time of data from the ONU 91 in the DBA cycle time T _DBA . For example, it is the ratio of the value obtained by subtracting the report transmission time T _SR (μs) of all ONUs from the DBA cycle time T _DBA (μs) to the DBA cycle time.
(Equation 3)
E _B = (T _DBA −T _SR ) / T _DBA × 100 (3)

Here, the report transmission time T _SR of all ONU, the transmission time of all ONU report signal, that is, overhead time other than the data communication time for all ONU, for example, represented by the following.
(Equation 4)
T _SR = N _ONU × (T _{ON / OFF} + T _TR + T _Sync ) × 0.016 (4)

Here, N _ONU is the number of ONUs. T _{ON / OFF} is an on / off time required for laser ON / OFF when one ONU starts / ends data transmission, and is, for example, 64 TQ. ONU1 cars the time the laser ON at the start of data transmission and _{T on,} the ONU1 cars and time _{T off} according to laser OFF when ending the data _{transmission,} the _{T ON / OFF = T on +} T off . T _TR is the report time ONU1 cars to send and receive data, such as 50TQ. T _Sync is a synchronization time required for one ONU unit to synchronize the received optical signal and the internal clock at the optical receiver, and is 42 TQ, for example. “0.016” is a coefficient resulting from a unit difference between μs and TQ.

  In the bandwidth utilization efficiency graph shown in FIG. 2, comparing the case where the DBA cycle time is 280 μs and the case where the DBA cycle time is 560 μs, the shorter the DBA cycle time, the greater the number of ONUs and the worse the bandwidth utilization efficiency. However, as shown in the delay time graph shown in FIG. 1, the shorter the DBA cycle time (280 μs), the shorter the delay time. Thus, there is a trade-off relationship between the bandwidth utilization efficiency and the delay time depending on the DBA cycle time.

The invention according to this embodiment, when the communication device 92 performs the allocation of bandwidth to each ONU91, the DBA cycle time as a parameter, the delay time T _D and the band use efficiency E _B respectively formula (1) and ( 2), the “delay time x” and the “reciprocal number y of bandwidth utilization efficiency” obtained for the DBA cycle time T _DBA are normalized by the equation (5) described later, and the normalized “delay time” The DBA cycle time that minimizes the sum of squares of “X” and “reciprocal number Y of bandwidth utilization efficiency” is obtained. Details will be described below.

  FIG. 3 shows an example of a bandwidth allocation system according to the embodiment of the present invention. The band allocation system according to the present embodiment includes an ONU 91, a communication device 92 that functions as an OLT, a splitter 94, and a host network 93. The splitter 94 connects the communication device 92 to a plurality of ONUs 91. The communication device 92 functions as a bandwidth allocation device, and the ONU 91 functions as an allocation destination device.

  FIG. 4 shows a configuration example of the communication device 92. The communication device 92 includes a bandwidth allocation device 21. The bandwidth allocation device 21 includes a control unit 211, a bandwidth allocation unit 212, a PON unit 213, and IFs 214 and 215. The IF 214 is connected to the upper network 93 and the IF 215 is connected to the ONU 91.

  The bandwidth allocation unit 212 allocates the communication bandwidth of each ONU 91. The control unit 211 controls the PON unit 213 based on the allocation by the bandwidth allocation unit 212. The PON unit 213 functions as a transmission / reception unit, receives a report signal including a transmission request amount requested by the ONU 91 from the ONU 91, and transmits a gate signal including a transmission permission amount and transmission timing for the ONU 91 to the ONU 91. The PON unit 213 may have a function of amplifying a communication signal. Here, the transmission permission amount is, for example, a transmission time (Grant Length), and the transmission timing is, for example, a transmission start time (Grant Start time).

  The bandwidth allocation method according to the present embodiment includes an allocation cycle time determination procedure and a bandwidth allocation procedure in order. In the allocation cycle time determination procedure, the bandwidth allocation unit 212 determines the allocation cycle time. In the band allocation procedure, the band allocation unit 212 allocates a band to the ONU 91 using the determined allocation cycle time so that signals from each ONU 91 do not collide.

  FIG. 5 shows an example of an allocation cycle time determination procedure. The bandwidth allocation unit 212 starts processing automatically or manually (S300), and has an information acquisition procedure S301, an adaptive range calculation procedure, a distance calculation procedure S304, and a DBA cycle time setting procedure S305 in order. In the adaptive range calculation procedure, a delay time adaptive range calculation procedure S302 and a band utilization efficiency adaptive range calculation procedure S303 are executed.

The bandwidth allocation unit 212 obtains information acquisition procedure S301 for acquiring access line information, delay time adaptive range calculation procedure S302 for calculating a delay time for each DBA cycle time from the acquired information, and bandwidth use efficiency for each DBA cycle time. The bandwidth use efficiency adaptive range calculation procedure S303 to be calculated is executed, the average distance _DONU for determining the DBA cycle time is calculated in the distance calculation procedure S304, and the DBA cycle time is set in the DBA cycle time setting procedure S305.

In the information acquisition procedure S301, the bandwidth allocation unit 212 acquires access line information. The access line information includes, for example, allocation conditions such as DBA cycle time and the number of ONUs, and information thereof. DBA cycle time, number of OUNs, ONU unit transmission time S _ONU , on _/ off time T _{ON / OFF} , synchronization time (Synctime) ) T _Sync , overlap time, report signal length, average distance D _ONU from communication device 92 to _ONU 91, report time T _TR per _ONU , transmission delay time T _T , discovery window (Discovery Windows) ) Including time. Here, the discovery window time is a time during which the OLT waits for an LLID registration request from the ONU.

FIG. 6 shows a specific example of the information acquisition procedure S301. The bandwidth allocation unit 212 acquires the existing DBA cycle time T _DBA (S401), acquires the number of ONUs (S402), acquires the transmission time S _ONU of the ONU alone (S403), and sets the _{ON / OFF} time T _{ON / OFF} . It acquires (S404), acquires Synctime, Overlap time and report signal length (S405), and acquires the average distance D _ONU to the _ONU 91 (S406). Then, using these values, the bandwidth allocation unit 212 calculates a report time T _TR per ONU (S407), calculates a transmission delay time T _T (S408), and calculates a discovery window time (S409). ). The report time T _TR , the transmission delay time T _T, and the discovery window time may be fixed values.

  FIG. 7 shows a specific example of the delay time adaptive range calculation procedure S302 for each DBA cycle time. The bandwidth allocation unit 212 performs the delay time calculation (S502) for each DBA cycle time (n) from the information acquired in the access line information acquisition procedure S301 (S501), confirms the end of the calculation (S504), If the DBA cycle time is calculated, the delay time calculation of the DBA cycle time is performed again (No in S504), and after calculating the delay time for every DBA cycle time (Yes in S504), the processing ends (S505). To do.

  FIG. 8 shows a specific example of the bandwidth utilization efficiency adaptive range calculation procedure S303 for each DBA cycle time. Based on the information acquired in the access line information acquisition procedure S301 (S601), the bandwidth allocation unit 212 performs a bandwidth utilization efficiency calculation (S602) for each DBA cycle time (n) and confirms the end of the calculation (S604). If there is an uncalculated DBA cycle time, the bandwidth use efficiency calculation of the DBA cycle time is performed again (No in S604), and after calculating the bandwidth use efficiency for every DBA cycle time (Yes in S604), the processing ends. (S605).

  FIG. 9 shows a specific example of the distance calculation procedure S304. The bandwidth allocation unit 212 uses the delay time acquired in the delay time adaptive range calculation procedure S302 for each DBA cycle time acquired in the delay time adaptive range calculation procedure S302 and the DBA cycle time acquired in the bandwidth use efficiency adaptive range calculation procedure S303. From the reciprocal of the bandwidth utilization efficiency (S701), the delay time for each DBA cycle time and the bandwidth utilization efficiency (reciprocal) are normalized (S702). Then, the bandwidth allocation unit 212 calculates the Euclidean distance with the normalized values of the cycle time, delay time, and bandwidth utilization efficiency calculation (reciprocal) in the DBA cycle time (S703), and confirms the end of the calculation (S705). If there is an uncalculated DBA cycle time, the Euclidean distance calculation of the DBA cycle time is performed again (No in S705), and after calculating the Euclidean distance for every DBA cycle time (Yes in S705), the processing ends (706). ).

  FIG. 10 shows a specific example of the DBA cycle time setting procedure S305. The bandwidth allocation unit 212 acquires the DBA cycle time of the shortest Euclidean distance using the Euclidean distance calculated in the distance calculation procedure S304 (S801), and sets the DBA cycle time as the DBA cycle time (S802).

As described above, the bandwidth use efficiency E _B is calculated by Equation (3), the delay time T _D is can be calculated with equation (1). In the present embodiment, these two expressions are converted into one expression with the DBA cycle time T _DBA as an axis.

FIG. 11 shows an example of characteristics of delay time and bandwidth utilization efficiency when providing a communication service. Bandwidth utilization efficiency E _B (T _T = 175.1 μs) when the number of ONUs N _ONUs is 64, the report transmission time T _SR is 147.5 μs, and the average distance D _ONU is 35 km. Y axis) and delay time T _D (X axis) were graphed.

In the present embodiment, the adaptive range is limited from the delay time and the band utilization efficiency as shown in FIG. FIG. 12 shows an example of characteristics of delay time and bandwidth utilization efficiency. This graph shows a case where the number of ONUs N _ONU is 64 and the average distance D _ONU is 20 km.

From the calculation formula (3), the bandwidth utilization efficiency E _B becomes 0% or more because it becomes negative when the DBA cycle time T _DBA becomes smaller than the report transmission time T _SR (constraint 2). Further, the value taken by the optimum DBA cycle time T _DBA does not become larger than the existing DBA cycle time (560 μs) (Constraint 1). In the bandwidth utilization efficiency adaptive range calculation procedure S303, the bandwidth utilization efficiency obtained by the constraints 1 and 2 is calculated.

In the delay time _{T D,} the calculation formula (1), becomes 0 or more (constraint 3). Further, the value taken by the optimal DBA cycle time T _DBA is never larger than the existing DBA cycle time (560 μs) (Constraint 4). In the delay time adaptive range calculation procedure S302, the delay time obtained by the constraints 3 and 4 is calculated.

The DBA cycle time range that can be set from the constraints 1 to 4 is set as the setting range of the band use efficiency and the delay time. Further, in order to make the magnitude relationship between the delay time and the good / bad bandwidth utilization efficiency coincide, the bandwidth utilization efficiency used in the distance calculation procedure S304 is reciprocal. At that time, when the delay time T _D = 0 and the normalized bandwidth utilization efficiency E _B = 0%, there is no delay time, and the bandwidth utilization efficiency before normalization can be set as a target point of 100%.

FIG. 13 shows an enlarged view of the setting range of the delay time and the bandwidth utilization efficiency obtained by the constraints 1 to 4. Bandwidth utilization efficiency is a reciprocal. Axis of the graph was obtained in 13, the bandwidth use efficiency E _B and the delay time T _D, since the unit (scale) is different, using Equation (5), normalizes ratably.

When delay time maximum value = X _max , delay time minimum value = X _min , bandwidth utilization efficiency maximum value = Y _max , bandwidth utilization efficiency minimum value = Y _min , normalized coordinate points (X ₁ , Y ₁ ) are ,
(Equation 5)
(X ₁ , Y ₁ )
_{= ((X 1 -X min)} / (X max -X min), (y 1 -Y min) / (Y max -Y min))
... (5)
The target point is (0, 0) because the delay time T _D = 0 and the bandwidth utilization efficiency E _B = 0 (%).

FIG. 14 shows an example of coordinate points after normalization. The number enclosed by the alternate long and short dash line is the DBA cycle time. A distance Ln between each coordinate point and the target point is calculated. The distance Ln is expressed as follows, for example.

Considering each coordinate point of the normalized graph,
· When DBA cycle time is 150ns, the distance L1, the delay time _{T D} is a minimum, the bandwidth use efficiency _{E B} is low.
· When DBA cycle time is 550 ns, the distance L9, bandwidth efficiency _{E B} is the biggest, the delay time _{T D} is longer.
When the DBA cycle time is 250 ns, the distance L3 is the shortest with the target point (0, 0). Therefore, among the delay time as a trade-off relationship T _D and bandwidth utilization E _B, the DBA cycle time to balance these two parameters among DBA cycle time that can be taken to the effective.

  FIG. 15 shows an example of the DBA cycle time when the number of ONUs is changed. FIG. 16 shows an example of the dispersion of the distance from the target point in each number of ONUs. V1 indicates when the DBA cycle time is minimum, V9 indicates when the DBA cycle time is maximum, and V3 indicates when the distance from the target point among the coordinate points of the normalized graph is minimum. Comparing the optimality of the DBA cycle time with the distance Ln from the target point shown in FIG. 14 described above, it was found that V3 according to the present embodiment is the closest from the target point for any number of ONUs and average distance.

  The invention according to the present embodiment is characterized by allocation of communication devices configured by DBA cycle time, delay time, and bandwidth utilization efficiency in a communication station. Therefore, in the provision of communication services, the processing procedure that enables optimal bandwidth allocation within the communication station adapted to various conditions and equipment conditions is recorded as a program code and recorded on a recording medium. Can be widely distributed in the market. For example, the bandwidth allocation device 21 may be realized by causing a computer to function as the control unit 211, the bandwidth allocation unit 212, and the PON unit 213. In this case, each configuration is realized by a CPU (Central Processing Unit) in the bandwidth allocation device 21 executing a computer program stored in a storage unit (not shown). As described above, the communication device 92 according to the present embodiment can be realized by a computer and a program, and can be recorded on a recording medium or provided through a network.

As described above, in the invention according to the present embodiment, the communication device 92 calculates the delay time T _D and the bandwidth utilization efficiency E _B for each DBA cycle time every time the allocation condition to each ONU 91 is updated. Determine the optimal DBA cycle time. For this reason, the invention according to the present embodiment provides a bandwidth allocation device, a bandwidth allocation method, a bandwidth allocation program, and a program that efficiently use a bandwidth that can be used by the communication device without delay when providing a communication service to a user. Can be provided.

  The present invention can be applied to the information communication industry. In the present embodiment, the example in which the communication device 92 is the OLT and the allocation destination device is the ONU 91 has been described. However, the present invention is not limited to this, and is not a technology specialized for communication equipment, but other fields ( Applicable to other industries).

21: Bandwidth allocation device 91: ONU
92: Communication device 93: Host network 94: Splitter 211: Control unit 212: Band allocation unit 213: PON unit 214, 215: IF

Claims (8)

  The delay time, which is the time from when the allocation destination device requests the transmission request amount data requested by the allocation destination device to the completion of transmission, and the ratio of the transmission time of the transmission request amount data to the existing allocation cycle time A certain bandwidth utilization efficiency is calculated using the allocation cycle time as a parameter, an allocation cycle time is determined using the obtained relative relationship between the delay time and the bandwidth utilization efficiency, and the allocation cycle time is determined using the determined allocation cycle time. A bandwidth allocation device comprising a bandwidth allocation unit that allocates bandwidth to a destination device. The bandwidth allocation unit normalizes the reciprocal of the delay time and the bandwidth utilization efficiency, and determines an allocation cycle time so that a square sum of the normalized delay time and the reciprocal of the bandwidth utilization efficiency is minimized;
The bandwidth allocating device according to claim 1. The bandwidth allocation unit normalizes the delay time and the bandwidth usage efficiency within a range that is equal to or shorter than the existing allocation cycle time and the delay time and bandwidth usage efficiency are 0 or more.
The bandwidth allocation device according to claim 2. A report signal including the transmission request amount is received from the allocation destination device, connected to a plurality of the allocation destination devices through an optical transmission line, and a gate signal including a transmission permission amount and a transmission timing determined by the band allocation unit is A transmission / reception unit for transmitting to the allocation destination device;
The bandwidth allocation unit calculates the delay time using the existing allocation cycle time of the allocation destination device and the transmission delay time of the allocation destination device, and the existing allocation cycle time of the allocation destination device and the allocation destination device The bandwidth utilization efficiency is calculated using the transmission time of the report signal from the network, and the allocation period time determined using the relative relationship between the delay time and the bandwidth utilization efficiency is Assigning bandwidth by determining the transmission permission amount and transmission timing for the allocation destination device so that signals do not collide,
The bandwidth allocation device according to any one of claims 1 to 3. The delay time, which is the time from when the allocation destination device requests the transmission request amount data requested by the allocation destination device to the completion of transmission, and the ratio of the transmission time of the transmission request amount data to the existing allocation cycle time An allocation cycle time determination procedure for calculating a certain bandwidth usage efficiency using the allocation cycle time as a parameter and determining an allocation cycle time using the obtained relative relationship between the delay time and the bandwidth usage efficiency;
A bandwidth allocation procedure for allocating a bandwidth to the allocation destination device using the determined allocation cycle time;
The bandwidth allocation method which has in order. In the allocation cycle time determination procedure, the bandwidth allocating unit normalizes the reciprocal of the delay time and the bandwidth usage efficiency, and allocates the normalized sum of the squares of the delay time and the reciprocal of the bandwidth usage efficiency to a minimum. Determine the cycle time,
The bandwidth allocation method according to claim 5. In the allocation cycle time determination procedure, the delay time and the bandwidth usage efficiency are normalized within a range that is equal to or less than the existing allocation cycle time and the delay time and bandwidth usage efficiency are 0 or more.
The bandwidth allocation method according to claim 6.   A bandwidth allocation program for causing a computer to execute the allocation cycle time determination procedure and the bandwidth allocation procedure according to any one of claims 5 to 7.

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