WO2022269707A1

WO2022269707A1 - Route control device, communication system, and route control method

Info

Publication number: WO2022269707A1
Application number: PCT/JP2021/023454
Authority: WO
Inventors: 優花岡本; 裕隆氏川; 慈仁酒井
Original assignee: 日本電信電話株式会社
Priority date: 2021-06-21
Filing date: 2021-06-21
Publication date: 2022-12-29
Also published as: JPWO2022269707A1

Abstract

A route control device according to one embodiment of the present invention has: a prediction time determination unit for determining the time available for prediction of future traffic volume for a communication route, the determination being performed on the basis of transmission time between a switch and an aggregation base station, transmission time between the switch and a remote station, control information that includes schedule information and traffic volume between the remote station and the aggregation base station, operation time of the switch, and a preset maximum allowable delay time; a selection unit for selecting, from among a plurality of algorithms in accordance with a prescribed priority, an algorithm that can determine a communication route within the time available for prediction determined by the prediction time determination unit; an execution unit for determining a communication route between the aggregation base station and the remote station by executing the algorithm selected by the selection unit; and, a switching control unit for controlling switching of communication routes using the switch so that the aggregation base station and the remote station communicate by the communication route determined by the execution unit.

Description

Route control device, communication system, and route control method

The present invention relates to a routing control device, a communication system, and a routing control method.

For example, in 5G (fifth generation mobile communication system), etc., a system configured to control traffic including MFH (Mobile Front Haul), MMH (Mobile Mid Haul), and MBH (Mobile Back Haul) is known. ing.

For example, a communication path between a plurality of DUs (Distribution units: remote stations) to which a plurality of RUs (Radio units: radio stations) are respectively connected and a plurality of CUs (Central units: aggregation base stations) is SW (switch ) are switched wireless communication systems.

Conventionally, in such a system, the amount of traffic arriving at a certain CU is predicted (by machine learning), and when the arrival of traffic that cannot be processed by the CU is expected, the SW is set so that the traffic is sent to a different CU. switch (for example, see Non-Patent Document 1).

However, in the conventional technology, since a path with guaranteed bandwidth between CU-DU is set according to a single algorithm, if the transmission delay due to the network configuration and the traffic of the network are different, the future traffic volume for the communication path It may happen that the forecast is not in time for the actual traffic. Bandwidth cannot be guaranteed if the forecast of future traffic volume is too late for the actual traffic.

In addition, in the conventional technology, CU switching is realized by turning off the power of CUs that are not in use. It was difficult to switch only traffic to another CU.

SUMMARY OF THE INVENTION The present invention has been made in view of the problems described above, and a routing control device, a communication system, and a routing control method that can determine and switch an efficient communication route even if traffic and propagation delays fluctuate. intended to provide

A route control device according to an embodiment of the present invention is a route control device that controls a switch that is provided between a plurality of aggregation base stations and a plurality of remote stations and switches communication paths, wherein the switch and the aggregation base station transmission time between and, transmission time between the switch and the remote station, control information including traffic volume and schedule information between the remote station and the aggregation base station, operation time of the switch, and previously a prediction time determination unit that determines a time available for predicting future traffic volume for a communication path based on the set maximum allowable delay time; and within the time available for prediction determined by the prediction time determination unit a selection unit that selects an algorithm capable of determining a communication path from among a plurality of algorithms according to a predetermined priority; an execution unit that determines a communication path between the remote stations, and a switching control unit that controls switching of the communication path by the switch so that the aggregation base station and the remote station communicate via the communication path determined by the execution unit. characterized by having

Further, a communication system according to an embodiment of the present invention includes a switch that is provided between a plurality of centralized base stations and a plurality of remote stations to switch communication paths, and a path control device that controls the switches. In a communication system, the path control device controls the transmission time between the switch and the aggregation base station, the transmission time between the switch and the remote station, and the traffic between the remote station and the aggregation base station. a prediction time determination unit that determines the time available for predicting future traffic volume for a communication path based on control information including volume and schedule information, operation time of the switch, and a preset maximum allowable delay time; a selection unit for selecting an algorithm capable of determining a communication path within the time available for prediction determined by the prediction time determination unit from among a plurality of algorithms according to a predetermined priority; an execution unit that determines a communication path between the aggregation base station and the remote station by executing an algorithm; and the aggregation base station and the remote station communicate with each other through the communication path determined by the execution unit. and a switching control unit for controlling switching of the communication path by the switch.

Further, a routing control method according to an embodiment of the present invention is a routing control method for controlling a switch provided between a plurality of aggregation base stations and a plurality of remote stations for switching communication paths, wherein the switches and the aggregation transmission time between the base station, transmission time between the switch and the remote station, control information including traffic volume and schedule information between the remote station and the aggregation base station, operation time of the switch, and a prediction time determination step of determining the time available for predicting the future traffic volume for the communication route based on a preset maximum allowable delay time, and determining the communication route within the time available for the determined prediction. A selection step of selecting a possible algorithm from among a plurality of algorithms according to a predetermined priority; and executing the selected algorithm to determine a communication path between the aggregation base station and the remote station. and a switching control step of controlling switching of the communication path by the switch so that the aggregation base station and the remote station communicate via the determined communication path.

According to the present invention, an efficient communication route can be determined and switched even if the traffic and propagation delay fluctuate.

It is a figure which shows the structural example of the communication system concerning one Embodiment. It is a figure which shows the structural example of the periphery of SW. 3 is a block diagram illustrating the functions and peripherals of a route control device according to one embodiment; FIG. FIG. 5 is a diagram schematically showing an example of predicted time determined by a predicted time determination unit; FIG. 10 is a diagram showing a specific example of a plurality of algorithms used by the selection unit for algorithm selection; (a) is a diagram schematically showing an operation example of a route control device when traffic volume is used. (b) is a diagram schematically showing an operation example of the route control device when control information is used. (a) is a diagram schematically showing the relationship with traffic when prediction time is sufficient. (b) is a diagram schematically showing the relationship with traffic when the prediction time is insufficient. (a) is a diagram showing the traffic volume of each DU predicted by the routing device. (b) is a diagram showing the traffic volume of each CU before and after the routing control device allocates the traffic volume. (a) is a diagram showing the traffic volume of each DU predicted by the route control device and the actual traffic volume. (b) is a diagram showing the traffic volume of each CU before and after the routing control device actually allocates the traffic volume. (a) is a diagram showing the traffic volume of each DU predicted by the routing device according to the embodiment, the traffic volume of each DU predicted by the routing device of the comparative example, and the actual traffic volume. (b) is a diagram showing a result of prediction and actual traffic volume allocation by the routing control device according to the embodiment and a result of prediction and actual traffic volume allocation by the routing control device of the comparative example; be.

A communication system according to one embodiment will be described using the drawings as follows. FIG. 1 is a diagram showing a configuration example of a communication system 1 according to one embodiment. A communication system 1 includes, for example, a core network 11 to which an end server 10 is connected, and a plurality of CUs (Central units: aggregation base stations) 12 are connected to configure a network as, for example, 5G (fifth generation mobile communication system). ing.

The CU 12 is connected to a plurality of DUs (Distribution Units: remote stations) 13 and the routing control device 3 via SWs (switches) 2, respectively.

Each DU 13 is connected to a plurality of RUs (Radio units) 14. The RU 14 accommodates a UE (User equipment: wireless terminal) 15 and enables the UE 15 to access the end server 10 .

The SW2 is provided between the plurality of CU12 and the plurality of DU13, and constitutes an MMH (Mobile Mid Haul) that switches the communication path between the CU12 and the DU13 according to the control of the path control device 3, for example. Hereinafter, when distinguishing between a plurality of CUs 12, they are distinguished by adding a number after #, such as CU#1 and CU#2. When distinguishing between a plurality of DUs 13, they are distinguished by adding a number after #, such as DU#1 to DU#4.

FIG. 2 is a diagram showing a configuration example around SW2. SW2 receives, for example, information indicating transmission time (t) and traffic volume (x) for communication from each of CU#1 and CU#2. Also, SW2 receives transmission time (t) and control information (c) for communication from each of DU#1 to DU#4. In the case of uplink communication, SW2 also receives information indicating the traffic volume (x) from each of DU#1 to DU#4.

Note that the control information is information that the UE 15 transmits to the DU 13 in order to access the end server 10, for example. The control information transmitted from each of DU#1 to DU#4 to SW2 includes, for example, the traffic volume and schedule information between DU13 and CU12. Specifically, the control information describes the next actual traffic transmission time (t _C ). Then, based on the control information, the allocated data will be sent in the next transmission.

Next, the route control device 3 according to one embodiment will be described in detail. FIG. 3 is a block diagram illustrating the functions and peripherals of the route control device 3 according to one embodiment. The route control device 3 has a time analysis unit 30, a prediction time determination unit 31, a storage unit 32, a selection unit 33, an execution unit 34, and a switching control unit 35, and is connected to SW2.

The time analysis unit 30 analyzes the traffic transmission time from the control information (C _DU ) received from the DU 13, and outputs the traffic transmission time (t _C ) and the control information to the prediction time determination unit 31 and the execution unit 34. .

Note that the time analysis unit 30 may receive a time stamp together with the control information and analyze the time (t _c ) at which the next traffic is actually transmitted based on the TTI (Transmission Time. Interval) cycle.

The prediction time determination unit 31 determines the transmission time ( _tCU ) between SW2 and CU12, the transmission time ( _tDU ) between SW2 and DU13, the traffic volume and schedule information (tC) between DU13 and _CU12 . etc.), the operation time (t _SW ) of SW2, and the preset maximum allowable delay time (for example, the required delay time of MMH: t _MMH ), to predict the future traffic volume for the communication path A usable time (predicted time: t _f ) is determined and output to the selection unit 33 .

In addition, the prediction time determination unit 31 determines, for example, the maximum allowable delay time of MMH according to the priority of traffic as the maximum allowable delay time used for determining the time that can be used for prediction, or A maximum allowable delay time determination unit 310 may be provided that determines 0 as the maximum allowable delay time used for time determination. In this case, the prediction time determination unit 31 can use the total time of the time from the reception of the control information to the arrival of the main signal and the maximum allowable delay time determined by the maximum allowable delay time determination unit 310 for prediction. Decide as time.

For example, the predicted time determining unit 31 obtains the current time (t _now ) from the grandmaster clock or the original clock. Also, the predicted time determining unit 31 may store the time required to calculate the allocation to each CU 12 from the estimated traffic information as being constant. In addition, the predicted time determination unit 31 may store the time required for SW2 to switch from the instruction to the switching to be constant. Further, the predicted time determination unit 31 may store the MMH request delay time as being constant.

FIG. 4 is a diagram schematically showing an example of the prediction time determined by the prediction time determining section 31. As shown in FIG. For example, the transmission time (t _DU ) between SW2 and DU13 could be as shown in equation (1) below.

t _DU = t _now + 1 - t _C (1)

The storage unit 32 stores the transmitted traffic volume and outputs it to the execution unit 34 as a continuous value together with the previously stored past traffic volume.

The selection unit 33 selects an algorithm capable of determining a communication route within the time (prediction time) that can be used for prediction determined by the prediction time determination unit 31 from among a plurality of algorithms according to a predetermined priority. A result is output to the execution unit 34 .

For example, based on the prediction time determined by the prediction time determination unit 31, the selection unit 33 selects traffic estimation when the prediction time is sufficient, and when the prediction time is not sufficient, time series prediction or the like is selected. Choose an algorithm. Note that the selection unit 33 may be configured to select a plurality of algorithms.

FIG. 5 is a diagram showing specific examples of a plurality of algorithms used by the selection unit 33 for algorithm selection. For example, the selection unit 33 selects at least one of a plurality of algorithms numbered 1 to 3 according to priority as an algorithm capable of determining a communication route within the predicted time.

Algorithms with higher priority (1>2>3) have higher prediction accuracy, but take longer to calculate.

For example, if the time available for prediction is longer than 0.7 ms, the selection unit 33 assigns a high priority RB (resource block) and estimates (calculates) traffic by multiplication using MCS (Modulation Coding Scheme) to select.

At this time, the selection unit 33 acquires the resource allocation number (RIV: resource indication value) and MCS from the control information (DCI: Downlink Control Information). For example, the selection unit 33 estimates the line quality from the MCS, obtains the traffic volume of the RB, and multiplies it by the RIV to calculate the traffic volume of each DU 13 .

In addition, when the time available for prediction is 0.3 to 0.7 ms, the selection unit 33 selects linear prediction with the second highest priority because the algorithm with the highest priority is longer than the prediction time. In linear prediction, increasing the amount of traffic increases the accuracy, but the time required for prediction increases. Therefore, the selection unit 33 adjusts the traffic volume to be used according to the time required for prediction.

In addition, when the time available for prediction is shorter than 0.3 ms, the selection unit 33 selects time-series prediction by machine learning with the third priority. In time-series prediction, as with linear prediction, increasing the amount of traffic improves accuracy, but the time required for prediction increases. Therefore, the selection unit 33 adjusts the traffic volume to be used according to the time required for prediction.

The execution unit 34 determines the communication route between the CU 12 and the DU 13 by executing the algorithm selected by the selection unit 33 .

For example, the execution unit 34 executes traffic estimation when the prediction time is sufficient, and executes time-series prediction when the prediction time is insufficient. Traffic estimation is an algorithm that predicts each traffic volume from control information. Time-series prediction is an algorithm that uses past traffic information to calculate the predicted traffic volume for the next time. In time-series prediction, the traffic information used may be changed according to the time available for prediction.

In addition, when the selection unit 33 selects a plurality of algorithms, the execution unit 34 may be configured to execute a plurality of algorithms, merge a plurality of prediction results, and output one prediction result. . For example, the execution unit 34 weights accuracy and time for multiple prediction results, and merges multiple prediction results by majority rule.

For example, the executing unit 34 includes an aggregating unit 340 for aggregating a plurality of algorithms, and when the selecting unit 33 selects a plurality of algorithms, the aggregating unit 340 executes the multiple algorithms and merges the multiple prediction results. and output one prediction result. At this time, the aggregating unit 340 weights the accuracy and time of the plurality of prediction results, and merges the plurality of prediction results by majority rule.

The switching control unit 35 has a determination unit 350 and an allocation determination unit 352, and controls communication path switching by SW2 so that the CU 12 and DU 13 communicate via the communication path determined by the execution unit 34.

For example, the determination unit 350 determines whether switching of SW2 is necessary based on the predicted traffic volume calculated by the execution unit 34, and if switching is not necessary, switches the communication path (path). However, when switching is necessary, the predicted traffic volume is output to the allocation determining unit 352 .

As a specific example, the determination unit 350 determines whether switching of SW2 is necessary by determining whether the predicted traffic volume exceeds a threshold value (bandwidth x 0.8, etc.).

Also, as shown in the following formula (2), the determination unit 350 determines that switching of SW2 is unnecessary when the traffic volume does not change in each communication path.

|x _CU#1 −x _CU#2 |<Max(x _CU )×0.1 (2)

In other cases, the determination unit 350 determines that communication path switching is necessary.

The allocation determination unit 352 determines the allocation of SW2 based on the predicted traffic volume input from the determination unit 350, and transmits an instruction to switch the communication path to SW2.

Then, SW2 switches the communication path according to the instruction sent by the path control device 3.

Next, each operation example of the route control device 3 will be described. FIG. 6 is a diagram schematically showing an operation example according to information used by the route control device 3. In FIG. FIG. 6(a) is a diagram schematically showing an operation example of the route control device 3 when the traffic volume (traffic information) is used. FIG. 6B is a diagram schematically showing an operation example of the route control device 3 when using control information.

As shown in FIG. 6(a), when the route control device 3 tries to switch the communication route using the actual traffic information, the traffic is only for a short period of time between the time the data is received and the time the data is transmitted. Prediction is not available in time for actual traffic because it cannot be used for prediction.

Therefore, in order to switch the communication route using the actual traffic information, the route control device 3 predicts the traffic using the previous data and switches the communication route. In this case, since the route control device 3 uses the previous data, the prediction accuracy of the traffic volume may be lowered.

As shown in FIG. 6(b), by using the received control information, the route control device 3, during the period from the time of receiving the control information to the time of data transmission, is used from prediction to communication route switching. You can secure the time you can.

In this case, even if the previous data is not used, the predicted time increases by the amount of time from when the control information is received until when the data is received. Moreover, by making predictions using the control information, the prediction accuracy is ensured more than using the previous data.

Then, if the time from receiving control information to receiving data is longer than the time required from predicting the amount of traffic to switching communication paths, it is possible to switch communication paths (real-time path switching) when data is received. Therefore, the route control device 3 analyzes the time required for prediction, and if the prediction time is sufficient, it can perform real-time path switching with high accuracy based on the control information.

FIG. 7 is a diagram schematically showing the relationship between the time available for prediction (prediction time) calculated by the route control device 3 and the traffic. FIG. 7(a) is a diagram schematically showing the relationship with traffic when the prediction time is sufficient. FIG. 7(b) is a diagram schematically showing the relationship with traffic when the prediction time is insufficient.

Here, let t _C be the time until the data calculated by the time analysis unit 30 is transmitted. The predicted time determination unit 31 determines the transmission time t _CU between CU12 and SW2, the transmission time t _DU between DU13 and SW2, the time t _C until data transmission, and the operation time of SW2 (time until allocation/switching of communication paths). Based on t _SW and the delay requirement t _MMH of MMH, the time (prediction time: t _f ) that can be used for predicting traffic volume is calculated by the following equation (3).

t _f =t _MMH −(Max(t _CU )+Max(t _DU −t _C )−t _SW )
... (3)

Then, the selection unit 33 selects an algorithm for calculating traffic volume for switching communication paths based on the predicted time _tf .

For example, as shown in FIG. 7A, when there is sufficient prediction time (for example, when there is time to transmit traffic), the selection unit 33 uses the control information to estimate (calculate) the traffic Algorithm to select. Then, the execution unit 34 executes a traffic estimation algorithm to calculate traffic and outputs it to the switching control unit 35 .

On the other hand, as shown in FIG. 7(b), when the prediction time is not enough (for example, when there is no time to transmit traffic), the selection unit 33 uses past traffic data to predict the future traffic volume. Choose an algorithm to perform series prediction. At this time, the selection unit 33 may change parameters such as the number of traffic data to be used according to the time required for prediction.

Then, the execution unit 34 predicts the next traffic volume using a time-series prediction algorithm and outputs it to the switching control unit 35 .

In other words, when the prediction time is sufficient, the route control device 3 controls the communication route in real time with high precision, and when the prediction time is not sufficient, the route control device 3 controls the communication route with an accuracy equivalent to switching the communication route using traffic information. to control the communication path.

Next, a specific example of the operation of the route control device 3 will be described. First, the case where the route control device 3 performs real-time path switching will be described.

For example, the time analysis unit 30 receives the control information (C _DU ), calculates the traffic transmission time (t _C =4 TTI=4 ms later), and transmits it to the prediction time determination unit 31 .

As shown in the following equations (4) and (5), the prediction time determination unit 31 determines the transmission time (t _C ) of traffic at the current time (t _now ) and the transmission/reception time (t _CU =0) between SW2 and CU12. .1 ms), the transmission/reception time between SW2 and DU13 (t _DU =0.05 ms), the CU allocation determination time (t _path =1 ms), and the communication path switching time (t _SW =0.1 ms). A time (t _f ) that can be used for prediction is calculated from the time required for transmission (t _fRT ) and the required delay time of MMH (t _MMH =5 ms).

_tfRT =tC+ _tDU - _tnow - _tpath - _tSW = _2.85ms (4)
_tf = _tMMH +tC _- _tnow -tCU- _tpath - _tSW = _7.8ms (5)

When the time of the DU 13 and the time of the route control device 3 are different, the predicted time determination unit 31 may synchronize the time, or transmit the time stamp from the DU 13, and actually arrive at SW2 from t _DU . A deviation from the time may be corrected.

Then, the selection unit 33 selects an algorithm based on the predicted time (t _f ). Here, since t _f =7.8 ms, the selection unit 33 selects the estimation (calculation, 1 ms) of the traffic transmitted by the control information. After executing the algorithm, the execution unit 34 transmits each traffic volume to the switching control unit 35 . The execution unit 34 does not perform transmission if switching of the communication path by SW2 is unnecessary.

For example, if the traffic volume for CU#1 is 8 Gbps and the traffic volume for CU#2 is 2 Gbps, the allocation determining unit 352 changes the allocation of DU13 as communication path switching. That is, the allocation determination unit 352 transmits a communication path switching instruction to SW2 in order to change the CU 12 to which the DU 13 is connected.

Next, an example of control performed by the route control device 3 when the prediction time is sufficient will be described.

The time analysis unit 30 receives the control information (C _DU ), calculates the traffic transmission time (t _C =4 TTI=1 ms later), and transmits it to the prediction time determination unit 31 .

The predicted time determination unit 31 acquires the transmission/reception time (t _CU =0.1 ms) between SW2 and CU12 and the transmission/reception time (t _DU =0.05 ms) between SW2 and DU13.

Then, as shown in the following equations (6) and (7), the prediction time determination unit 31 determines the transmission time (t _C ) of the traffic at the current time (t _now ) and the transmission/reception time (t _CU = 0.1 ms), transmission/reception time between SW2-DU13 (t _DU = 0.05 ms), CU assignment decision time (t _path = 1 ms), and communication path switching time (t _SW = 0.1 ms) , the time required for traffic transmission (t _fRT ) and the required delay time of MMH (t _MMH =1 ms), the time (t _f ) that can be used for prediction is calculated.

t _fRT =t _C +t _DU -t _now -t _path -t _SW =-0.15 ms (6)
_tf = _tMMH +tC _- _tnow - _tCU - _tpath - _tSW =0.8 ms (7)

Then, the selection unit 33 selects an algorithm based on the predicted time (t _f ). Here, since t _f =0.8 ms, the selection unit 33 selects the estimation (calculation, 0.7 ms) of the traffic transmitted by the control information. After executing the algorithm, the execution unit 34 transmits each traffic volume to the switching control unit 35 . The execution unit 34 does not perform transmission if switching of the communication path by SW2 is unnecessary.

For example, if the traffic volume for CU#1 is 9 Gbps and the traffic volume for CU#2 is 8 Gbps, the allocation determination unit 352 changes the allocation of DU13 as communication route switching. That is, the allocation determination unit 352 transmits a communication path switching instruction to SW2 in order to change the CU 12 to which the DU 13 is connected.

Next, an example of control performed by the route control device 3 when the prediction time is insufficient will be described.

The time analysis unit 30 receives the control information (C _DU ), calculates the traffic transmission time (t _C =4 TTI=0.5 ms later), and transmits it to the prediction time determination unit 31 .

Then, as shown in the following equations (8) and (9), the prediction time determination unit 31 determines the transmission time (t _C ) of the traffic at the current time (t _now ), the transmission/reception time (t _CU = 0.1 ms), transmission/reception time between SW2-DU13 (t _DU = 0.05 ms), CU assignment decision time (t _path = 1 ms), and communication path switching time (t _SW = 0.1 ms) , the time required for traffic transmission (t _fRT ) and the required delay time of MMH (t _MMH =1 ms), the time (t _f ) that can be used for prediction is calculated.

t _fRT =t _C +t _DU -t _now -t _path -t _SW =-0.55 ms (8)
_tf = _tMMH +tC _- _tnow -tCU- _tpath - _tSW = _0.3ms (9)

Instead of the storage unit 32, the route control device 3 is provided with a traffic prediction unit that predicts each traffic volume using the previous traffic volume. may be used to predict each traffic volume.

Then, the selection unit 33 selects an algorithm based on the predicted time (t _f ). Here, since t _f =0.3 ms, the selection unit 33 selects an algorithm for predicting future traffic information from past traffic information (determines the amount of data to be used in time for the prediction time). After executing the algorithm, the execution unit 34 transmits each traffic volume to the switching control unit 35 . The execution unit 34 does not perform transmission if switching of the communication path by SW2 is unnecessary.

Next, an example of control performed by the route control device 3 without using control information will be described.

Then, as shown in the following formula (10), the predicted time determination unit 31 determines the transmission/reception time between SW2 and CU12 (t _CU =0.1 ms), the transmission/reception time between SW2 and DU13 (t _DU =0.05 ms) , CU allocation decision time (t _path = 1 ms), and communication path switching time (t _SW = 0.1 ms), the time required for traffic transmission (t _fRT ) and the required delay time of MMH (t _MMH = 1 ms), it is possible to determine whether there is time to use for switching (t determination).

t judgment = t _MMH - t _DU - t _CU - t _path - t _SW = -0.25 ms (10)

At this time, the judgment time (t judgment) is a negative value. In other words, even if the communication path is switched according to the amount of traffic, it is too late.

Therefore, the route control device 3 switches the communication route based on the prediction of the traffic volume in the next section. In this case, the time available for prediction increases by 4 TTI periods (1 ms), so t _f =0.75 ms. Then, the selection unit 33 selects an algorithm based on the predicted time (tf).

Here, since t _f =0.75 ms, an algorithm for predicting future traffic information from past traffic information is selected (the amount of data to be used is determined in time for the prediction time). However, since this is time-series prediction, the prediction accuracy is lower than when control information is used.

After executing the algorithm, the execution unit 34 transmits each traffic volume to the switching control unit 35 . The execution unit 34 does not perform transmission if switching of the communication path by SW2 is unnecessary.

For example, if the traffic volume for CU#1 is 8 Gbps and the traffic volume for CU#2 is 7.5 Gbps, the allocation determining unit 352 does not allocate DU13 as communication path switching.

Next, a specific example in which the route control device 3 switches the communication route will be described. The route control device 3 controls switching of communication routes by changing the allocation of the traffic volume of each DU 13 to each CU 12 . As a result, the route control device 3 can distribute the load on the communication route for each CU 12 .

A case where the number of CUs 12 is 2 (CU#1, CU#2) and the number of DUs 13 is 8 (DU#1 to DU#8) will be described below as an example.

FIG. 8 is a diagram schematically showing the traffic volume of each DU 13 predicted by the routing device 3 and the result of allocating the traffic volume of each DU 13 to each CU 12 using the predicted traffic volume. FIG. 8(a) is a diagram showing the traffic volume of each DU 13 predicted by the routing device 3. FIG. FIG. 8(b) is a diagram showing the traffic volume of each CU 12 before and after allocation of traffic volume by the route control device 3 (before and after load distribution). Here, it is assumed that the traffic volume predicted by the route control device 3 and the actual traffic volume match.

If the traffic volume of each DU 13 after the routing control device 3 executes the algorithm described above is the traffic volume shown in FIG. , CU#1 has a traffic volume of 8 Gbps, and CU#2 has a traffic volume of 2 Gbps (before load balancing).

At this time, the traffic volume occupies 80% of the bandwidth of CU#1, which is 10 Gbps, and the bandwidth of CU#2 is sufficiently empty (judgment condition: |8−2|>8×0.1). , the route control device 3 switches the communication route by SW2.

For example, the allocation determination unit 352 changes the allocation of the traffic volume of each DU 13 so as to distribute the traffic volume of each DU 13 to each CU 12, and transmits an instruction to that effect to SW2.

As a result, as shown after load distribution in FIG. be.

FIG. 9 is a diagram schematically showing the result of allocating the traffic volume of each DU 13 to each CU 12 using the traffic volume of each DU 13 predicted by the routing device 3 and the actual traffic volume. FIG. 9(a) is a diagram showing the traffic volume of each DU 13 predicted by the routing device 3 and the actual traffic volume. FIG. 9(b) is a diagram showing the traffic volume of each CU 12 before and after the route control device 3 actually allocates the traffic volume (before and after load distribution).

If the traffic volume of each DU 13 after the routing control device 3 executes the algorithm described above is the traffic volume shown in the upper part of FIG. For example, CU#1 has a traffic volume of 8 Gbps, and CU#2 has a traffic volume of 2 Gbps.

However, if the actual traffic volume is the traffic volume shown in the lower part of FIG. become excessive.

At this time, since there is sufficient free space in the band of CU#2 (judgment condition: |8-2|>8×0.1), the route control device 3 switches the communication route using SW2.

As a result, as shown after load distribution in FIG. 9B, even if an error occurs in the prediction of the traffic volume by the route control device 3, there is a margin so that the bandwidth of each CU 12 is not exceeded. .

FIG. 10 shows the result of assigning the traffic volume of each DU 13 based on the traffic volume of each DU 13 predicted by the routing control device 3 according to one embodiment, and the traffic volume of each DU 13 predicted by the routing control device of the comparative example. FIG. 10 is a diagram schematically showing the result of allocating the traffic volume of each DU 13 by means of

FIG. 10A is a diagram showing the traffic volume of each DU 13 predicted by the routing device 3 according to the embodiment, the traffic volume of each DU 13 predicted by the routing device of the comparative example, and the actual traffic volume. . FIG. 10(b) shows the result of prediction and actual traffic volume allocation by the routing control device 3 according to the embodiment and the result of prediction and actual traffic volume allocation by the routing control device of the comparative example. FIG. 4 is a diagram showing;

As shown in FIG. 10, the result of allocating the traffic volume of each DU 13 based on the traffic volume of each DU 13 predicted by the routing device 3 according to one embodiment shows that the actual traffic volume is larger than the predicted traffic volume. It is shown that the communication path was suitably switched even if the

On the other hand, as a result of allocating the traffic volume of each DU 13 based on the traffic volume of each DU 13 predicted by the route control device of the comparative example, when the actual traffic volume exceeds the predicted traffic volume, the CU#1 The amount of traffic is excessive with respect to the bandwidth of 10 Gbps.

In other words, since the routing control device 3 has high traffic volume prediction accuracy, even if an error occurs in the traffic volume prediction, there is a margin so that the bandwidth of each CU 12 is not exceeded.

In this way, the communication system 1 according to one embodiment selects an algorithm that can determine a communication route within a time that the route control device 3 can use for predicting traffic volume, among a plurality of algorithms according to a predetermined priority. , an efficient communication route can be determined and switched even if the traffic or propagation delay fluctuates.

It should be noted that each function of the path control device 3 described above may be configured partially or wholly by hardware such as a PLD (Programmable Logic Device) or FPGA (Field Programmable Gate Array), or a processor such as a CPU. may be configured as a program executed by

For example, the route control device 3 according to one embodiment can be implemented using a computer and a program, and the program can be recorded on a storage medium or provided through a network.

1... communication system, 2... SW, 3... path control device, 10... end server, 11... core network, 12... CU, 13... DU, 14... RU, 15... UE, 30... Time analysis unit, 31... Prediction time determination unit, 32... Storage unit, 33... Selection unit, 34... Execution unit, 35... Switching control unit 310 Maximum allowable delay time determination unit 340 Consolidation unit 350 Judgment unit 352 Allocation determination unit

Claims

In a route control device that controls a switch that is provided between a plurality of aggregation base stations and a plurality of remote stations and that switches communication routes,
control information including transmission time between the switch and the aggregation base station, transmission time between the switch and the remote station, traffic volume and schedule information between the remote station and the aggregation base station; a prediction time determination unit that determines a time that can be used to predict future traffic volume for a communication path based on the operating time of the switch and a preset maximum allowable delay time;
a selection unit that selects an algorithm capable of determining a communication route within the time available for prediction determined by the prediction time determination unit from among a plurality of algorithms according to a predetermined priority;
an execution unit that determines a communication route between the aggregation base station and the remote station by executing the algorithm selected by the selection unit;
a switching control unit that controls switching of communication paths by the switch so that the aggregation base station and the remote station communicate via the communication path determined by the execution unit.
The selection unit
Based on the time determined by the prediction time determination unit, when there is time to transmit traffic, an algorithm for estimating traffic is selected, and when there is no time to transmit traffic, time-series prediction of traffic volume is performed. 2. The route control device according to claim 1, wherein an algorithm for determining the route is selected.
The prediction time determination unit
Determine the maximum allowable delay time of MMH according to the priority of traffic as the maximum allowable delay time used for determining the time available for prediction, or the maximum allowable delay time used for determining the time available for prediction further comprising a maximum allowable delay time determining unit for determining 0, the total time of the time from the reception of the control information to the arrival of the main signal and the maximum allowable delay time determined by the maximum allowable delay time determining unit; 3. The route control device according to claim 1, wherein the available time is determined at the time of prediction.
The selection unit
Select multiple algorithms,
The execution unit
2. An aggregating unit that executes a plurality of algorithms selected by the selecting unit, weights accuracy or time for a plurality of prediction results, and outputs a single prediction result that is merged. 4. The route control device according to any one of items 1 to 3.
In a communication system comprising a switch provided between a plurality of aggregation base stations and a plurality of remote stations for switching communication paths, and a path control device for controlling the switch,
The route control device is
control information including transmission time between the switch and the aggregation base station, transmission time between the switch and the remote station, traffic volume and schedule information between the remote station and the aggregation base station; a prediction time determination unit that determines a time that can be used to predict future traffic volume for a communication path based on the operating time of the switch and a preset maximum allowable delay time;
a selection unit that selects an algorithm capable of determining a communication route within the time available for prediction determined by the prediction time determination unit from among a plurality of algorithms according to a predetermined priority;
an execution unit that determines a communication route between the aggregation base station and the remote station by executing the algorithm selected by the selection unit;
a switching control unit that controls switching of the communication path by the switch so that the aggregation base station and the remote station communicate via the communication path determined by the execution unit.
In a route control method for controlling a switch provided between a plurality of aggregation base stations and a plurality of remote stations for switching communication routes,
control information including transmission time between the switch and the aggregation base station, transmission time between the switch and the remote station, traffic volume and schedule information between the remote station and the aggregation base station; a prediction time determination step of determining a time available for predicting future traffic volume for the communication path based on the operating time of the switch and a preset maximum allowable delay time;
a selection step of selecting an algorithm capable of determining a communication route within the time available for the determined prediction from among a plurality of algorithms according to a predetermined priority;
executing a selected algorithm to determine a communication path between the aggregation base station and the remote station;
A route control method, comprising: a switching control step of controlling switching of the communication route by the switch so that the aggregation base station and the remote station communicate with each other through the determined communication route.