COMMUNICATION CONTROL DEVICE AND COMMUNICATION CONTROL METHOD

Abstract

To facilitate expansion of system capacity and improve throughput.SOLUTION: A communication control device connected to a plurality of baseband devices respectively managed by a plurality of operators and allocating, to the plurality of operators, respective bands of a plurality of wireless devices shared by the plurality of operators includes an allocation unit that allocates the bands for the respective wireless devices to the plurality of operators according to a band use upper limit set for the wireless devices such that the bands used by the plurality of operators do not exceed the band use upper limit, and an output unit configured to output allocation information indicating the bands allocated to the plurality of operators by the allocation unit to the respective baseband devices.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a communication control device and a communication control method. [Background technology]

[0002] In recent years, wireless communication systems are beginning to introduce services using fifth-generation mobile communications (5G), which enables high-speed, large-volume data communication. 5G services use radio waves with higher frequencies than LTE (Long Term Evolution), such as millimeter waves. Such high-frequency radio waves tend to have a high degree of directivity and do not easily penetrate obstructions, which results in smaller cell radii. As a result, building wireless communication systems requires the installation of base station equipment at high density.

[0003] Specifically, since a base station device is separated into, for example, a baseband device (CU / DU: Central Unit / Distributed Unit) that performs baseband processing and a radio device (RU: Radio Unit) that performs radio processing, RUs with antennas are densely arranged. Therefore, a communication carrier (MNO: Mobile Network Operator) that builds a wireless communication system can efficiently expand the communication area and system capacity by cooperating with other MNOs to install shareable RUs. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2016-192632 A [Patent Document 2] JP 2011-82709 A Summary of the Invention [Problem to be solved by the invention]

[0005] One method of installing RUs shared by multiple MNOs (hereinafter referred to as "shared RUs") is to replace the dedicated RUs already installed for each MNO with shared RUs. As a result, each MNO's CU / DU will be connected to a larger number of shared RUs than when connected to dedicated RUs, and the front haul (FH) lines connecting the CU / DU and the shared RUs will be shared by multiple MNOs.

[0006] However, even when replacing dedicated RUs with shared RUs, it is difficult to upgrade and expand each MNO's CU / DU and FH lines, and if each MNO uses a shared RU, there is a problem that the output capacity of the CU / DU and the capacity of the FH line may be exceeded.In other words, if the bandwidth used by the shared RU is increased in accordance with the number of MNOs sharing the shared RU, the capacity of the CU / DU and FH line will not be able to keep up with this increase in bandwidth, limiting the expansion of system capacity.

[0007] The disclosed technology has been made in consideration of the above points, and has an object to provide a communication control device and a communication control method that can promote an expansion of system capacity and improve throughput. [Means for solving the problem]

[0008] In one aspect, the communication control device disclosed in the present application is a communication control device that allocates to multiple operators the bandwidths of multiple radio devices connected to multiple baseband devices managed by the multiple operators respectively and shared by the multiple operators, and has an allocation unit that allocates the bandwidths of the radio devices to the multiple operators in accordance with a bandwidth usage upper limit set for each of the radio devices so that the bandwidth used by the multiple operators does not exceed the bandwidth usage upper limit, and an output unit that outputs allocation information indicating the bandwidths allocated to the multiple operators by the allocation unit to each of the multiple baseband devices. Effect of the Invention

[0009] According to one aspect of the communication control device and communication control method disclosed in the present application, it is possible to promote an expansion of the system capacity and improve the throughput. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a diagram illustrating an example of the configuration of a wireless communication system. [Diagram 2] FIG. 2 is a block diagram showing a configuration of the communication control device according to the first embodiment. [Diagram 3] FIG. 3 is a block diagram showing a configuration of a CU / DU according to the first embodiment. [Figure 4] FIG. 4 is a sequence diagram showing a communication method. [Diagram 5] FIG. 5 is a flow diagram showing the band optimization method according to the first embodiment. [Figure 6] FIG. 6 is a flow diagram continuing from FIG. [Figure 7] FIG. 7 is a diagram illustrating the initial use band. [Figure 8] FIG. 8 is a diagram showing a specific example of the use band matrix O. In FIG. [Figure 9] FIG. 9 is a diagram showing a specific example of the optimal weighting matrix W. [Figure 10] FIG. 10 is a flow diagram showing the search pattern identification process. [Figure 11] FIG. 11 is a diagram for explaining a specific example of a search pattern. [Figure 12] FIG. 12 is a flow diagram showing a band optimization method according to the second embodiment. [Figure 13] FIG. 13 is a flow diagram continuing from FIG. [Figure 14] FIG. 14 is a flow diagram showing the search pattern identification process. [Figure 15] FIG. 15 is a diagram for explaining a specific example of a search pattern. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, embodiments of a communication control device and a communication control method disclosed in the present application will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

[0012] (Embodiment 1) Fig. 1 is a diagram showing an example of the configuration of a wireless communication system according to a first embodiment. In the wireless communication system shown in Fig. 1, multiple CU / DUs 200 managed by different MNOs share multiple shared RUs 20. That is, the multiple CU / DUs 200 are connected to the multiple shared RUs 20 via an L2 switch 10. A line connecting each CU / DU 200 and the shared RU 20 is a fronthaul line (FH line). In addition, the multiple CU / DUs 200 are connected to a common communication control device 100.

[0013] The communication control device 100 is called, for example, a RIC (RAN Intelligent Controller) and controls a base station. The communication control device 100 controls the CU / DU 200, which is a baseband device constituting a base station. Specifically, the communication control device 100 assigns the band of each shared RU 20 to the CU / DU 200 corresponding to a plurality of MNOs. At this time, the communication control device 100 assigns the band to each CU / DU 200 so that the band used by each shared RU 20 does not exceed a predetermined amount and the data output amount from each CU / DU 200 does not exceed a predetermined amount. Furthermore, the communication control device 100 optimizes the band used by each shared RU 20 so that a predetermined metric is maximized, and determines the band used by each terminal device (UE: User Equipment) 30 for wireless communication with the shared RU 20. The detailed configuration and operation of the communication control device 100 will be described later.

[0014] The CU / DU 200 is a baseband device constituting a base station. The CU / DU 200 connects to a core network for each MNO (not shown) and performs baseband processing on data for each MNO. The CU / DU 200 also connects to multiple shared RUs 20 via FH lines and acquires information about UEs 30 that wirelessly communicate with each shared RU 20 and that are under the jurisdiction of the own MNO. The CU / DU 200 then notifies the communication control device 100 of the acquired UE information.

[0015] Furthermore, when the communication control device 100 allocates a bandwidth for the shared RU 20 to the CU / DU 200, the CU / DU 200 executes scheduling in the allocated bandwidth, and transmits and receives data to and from the shared RU 20 via the FH line. The detailed configuration and operation of the CU / DU 200 will be described later.

[0016] The L2 switch 10 is provided on the FH line, and connects a plurality of CU / DUs 200 and a plurality of shared RUs 20 together.

[0017] The shared RU 20 is a radio device constituting a base station. The shared RU 20 connects to multiple CU / DUs 200 corresponding to multiple MNOs, and performs radio processing on data. That is, the shared RU 20 wirelessly transmits and receives data to and from UEs 30 in a cell. The shared RU 20 can use multiple bands for each MNO, and communicates with the CU / DUs 200 of each MNO using a band instructed by the CU / DUs 200 corresponding to each MNO, and also wirelessly communicates with UEs 30 under the jurisdiction of that MNO.

[0018] The UE 30 is a terminal device capable of wireless communication. The UE 30 performs wireless communication with the shared RU 20 that forms the cell in which the UE 30 is located. The UE 30 is managed by one of multiple MNOs that share the shared RU 20, and transmits and receives data to and from the CU / DU 200 of the MNO.

[0019] 2 is a block diagram showing a configuration of the communication control device 100 according to the embodiment 1. The communication control device 100 shown in FIG.

[0020] The input / output unit 110 is connected to multiple CU / DUs 200, accepts input of information from the CU / DUs 200, and outputs information to the CU / DUs 200. Specifically, the input / output unit 110 accepts input of information related to the UEs 30 managed by the respective MNOs from each CU / DU 200. In addition, the input / output unit 110 outputs allocation information related to the bandwidth used by the shared RUs 20 allocated to each CU / DU 200.

[0021] The processor 120 includes, for example, a CPU (Central Processing Unit), an FPGA (Field Programmable Gate Array), or a DSP (Digital Signal Processor), and generally controls the entire communication control device 100. Specifically, the processor 120 includes a reception quality collecting unit 121, an FH band setting unit 122, a band optimizing unit 123, and an allocation information generating unit 124.

[0022] The reception quality collecting unit 121 collects information on the reception quality at the UE 30 from notification information input from the CU / DU 200 of each MNO to the input / output unit 110. That is, the reception quality collecting unit 121 collects information on the reception quality at each UE 30 that wirelessly communicates with the shared RU 20. For example, RSRP (Reference Signal Received Power) is used as the reception quality.

[0023] The FH band setting unit 122 manages the band of the FH line for each shared RU 20, and notifies the band optimization unit 123 of a predetermined band usage upper limit set for each CU / DU 200 and each shared RU 20. Here, the band of the FH line corresponds to the radio band between the shared RU 20 and the UE 30, and the entire band is divided into usable bands for each MNO. Furthermore, the usable band for each MNO is divided into multiple unit bands of a predetermined bandwidth. The FH band setting unit 122 notifies the band optimization unit 123 of the number of unit bands that is the upper limit of the usable band for each MNO for the FH line of the shared RU 20.

[0024] The bandwidth optimization unit 123 determines the bandwidth to be used for each shared RU 20 in accordance with the bandwidth usage upper limit notified by the FH bandwidth setting unit 122. That is, the bandwidth optimization unit 123 allocates the bandwidth for each shared RU 20 to each MNO such that the number of unit bandwidths used for each MNO in each shared RU 20 does not exceed a predetermined bandwidth usage upper limit. Furthermore, the bandwidth optimization unit 123 calculates a metric that is an index of the fairness of the bandwidth allocation to each MNO and the throughput based on the reception quality in each UE 30, and optimizes the bandwidth allocation to each MNO so as to maximize this metric. Furthermore, while optimizing the bandwidth allocation to each MNO, the bandwidth optimization unit 123 determines the UEs 30 that will wirelessly communicate with the shared RU 20 in each unit bandwidth of the shared RU 20.

[0025] The allocation information generation unit 124 generates allocation information indicating the band for each shared RU 20 allocated to each MNO by the band optimization unit 123. At this time, the allocation information generation unit 124 includes, in the allocation information addressed to the CU / DU 200 corresponding to each MNO, information indicating the unit band for each shared RU 20 allocated to that MNO, and identification information of the UE 30 that wirelessly communicates with the shared RU 20 in each unit band. The allocation information is output from the input / output unit 110 to the CU / DU 200 corresponding to each MNO.

[0026] The memory 130 includes, for example, a random access memory (RAM) or a read only memory (ROM), and stores information used in processing by the processor 120.

[0027] 3 is a block diagram showing the configuration of a CU / DU 200 according to embodiment 1. The CU / DU 200 shown in FIG.

[0028] The input / output unit 210 is connected to the communication control device 100, and outputs information to the communication control device 100, while accepting input of information from the communication control device 100. Specifically, the input / output unit 210 accepts input of allocation information indicating the band for each shared RU 20 allocated to the own MNO. The input / output unit 210 also outputs notification information notifying the reception quality of UE 30 belonging to the own MNO.

[0029] The processor 220 includes, for example, a CPU, an FPGA, or a DSP, and generally controls the entire CU / DU 200. Specifically, the processor 220 includes a UE information acquisition unit 221, a notification information generation unit 222, and a scheduling unit 223.

[0030] The UE information acquisition unit 221 acquires information about the UE 30 that wirelessly communicates with multiple shared RUs 20 connected to the CU / DU 200. Specifically, the UE information acquisition unit 221 acquires UE information related to the reception quality, such as the RSRP, of each UE 30 from each shared RU 20.

[0031] The notification information generation unit 222 generates notification information for notifying the communication control device 100 of the UE information acquired by the UE information acquisition unit 221. That is, the notification information generation unit 222 generates notification information including information on reception quality in the UE 30 that wirelessly communicates with each shared RU 20. Then, the notification information generation unit 222 causes the input / output unit 210 to output the generated notification information to the communication control device 100.

[0032] The scheduling unit 223 performs scheduling of the FH link for each shared RU 20 in accordance with the allocation information received by the input / output unit 210. That is, the scheduling unit 223 sets the FH transceiver unit 240 to communicate with the shared RU 20 to which a band has been allocated to its own MNO, and performs scheduling to allocate radio resources to UEs 30 that use each unit band.

[0033] The memory 230 includes, for example, a RAM or a ROM, and stores information used in processing by the processor 220.

[0034] The FH transceiver 240 transmits and receives data to and from the shared RU 20 via the FH line in accordance with the scheduling by the scheduling unit 223. That is, the FH transceiver 240 transmits data addressed to a UE 30 that uses a band allocated to the shared RU 20 by its own MNO. The FH transceiver 240 also receives data transmitted from a UE 30 that uses a band allocated to the shared RU 20 by its own MNO.

[0035] Next, a communication method in a wireless communication system including the communication control device 100 and CU / DU 200 configured as described above will be described with reference to the sequence diagram shown in Fig. 4. In the following description, it is assumed that two shared RUs 20 are shared by two CU / DUs 200 corresponding to MNO#0 and MNO#1, respectively. That is, the CU / DU 200 corresponding to MNO#0 communicates with a UE 30 managed by MNO#0 via the shared RU 20, and the CU / DU 200 corresponding to MNO#1 communicates with a UE 30 managed by MNO#1 via the shared RU 20.

[0036] The two shared RUs 20 periodically transmit a predetermined reference signal over the air (steps S101, S102). The UE 30 of each MNO receives the reference signal from each shared RU 20 and measures the reception quality, for example, RSRP. The UE 30 then reports information on the measured reception quality to the CU / DU 200 of the same MNO via the shared RU 20 (steps S103, S104), and the CU / DU 200 outputs notification information including the reception quality information to the communication control device 100.

[0037] When communication control device 100 acquires information on the reception quality in UE 30, the bandwidth used by each shared RU 20 is optimized (step S105). That is, in each shared RU 20, the number of unit bandwidths allocated to each MNO is set so as not to exceed a predetermined bandwidth usage upper limit, and the bandwidth allocation to each MNO is optimized so as to maximize a predetermined metric based on the reception quality of UE 30. Then, allocation information indicating the optimized bandwidth allocation is output to CU / DU 200 (step S106), and the bandwidth used by CU / DU 200 for each shared RU 20 is changed.

[0038] The CU / DU 200 transmits data to the shared RU 20 using the changed band (steps S107, S108). At this time, the communication control device 100 optimizes the band, allocating a band to each CU / DU 200 so as not to exceed the capacity of the FH line between the CU / DU 200 and the shared RU 20, so that the output capacity of the CU / DU 200 and the capacity of the FH line are not exceeded. In addition, data is transmitted and received between the shared RU 20 and the UE 30 using a radio band corresponding to this band (step S109). Each UE 30 communicates using the band allocated to maximize the metric, which expands the system capacity and improves throughput.

[0039] Next, a band optimization method according to the first embodiment will be described with reference to the flow charts shown in Figs. 5 and 6. The band optimization described below is executed by the band optimization unit 123 of the communication control device 100.

[0040] First, an initial value of the usage bandwidth for each shared RU 20 (hereinafter referred to as "initial usage bandwidth") is set according to the bandwidth usage upper limit notified by FH bandwidth setting unit 122 (step S201). That is, the unit bandwidth used by each MNO in the shared RU 20 is determined so that the usage bandwidth of each shared RU 20 does not exceed the bandwidth usage upper limit. Specifically, consider the case where CU / DU 200 of MNOs #0 and #1 use RUs #0 to #4, as shown in FIG. 7.

[0041] FIG. 7(a) is a diagram showing the bandwidth usage when RU#0 and #1 are dedicated RUs for MNO#0, and RU#2 and #3 are dedicated RUs for MNO#1. As shown in FIG. 7(a), the unit bandwidth F#0-#4 of RU#0 is assigned to the first CU / DU of MNO#0, and the unit bandwidth F#0-#4 of RU#1 is assigned to the second CU / DU of MNO#0. Similarly, the unit bandwidth F#0-#4 of RU#2 is assigned to the first CU / DU of MNO#1, and the unit bandwidth F#0-#4 of RU#3 is assigned to the second CU / DU of MNO#1. In this case, it is assumed that RU#0-#4 are changed to shared RUs 20. It is also assumed that FH bandwidth setting unit 122 sets the bandwidth usage upper limit for RU#0-#4, which are shared RUs 20, to the same number of unit bandwidths as the bandwidth usage in FIG. 7(a). In other words, the bandwidth usage upper limit for each of RUs #0 to #4 is set to four unit bandwidths.

[0042] In this case, the initial use band can be, for example, as shown in Fig. 7(b), such that unit bands F#0 and #1 of RU#0 are assigned to the first CU / DU200 of MNO#0, and unit bands F#2 and #3 of RU#0 are assigned to the first CU / DU200 of MNO#1. Also, unit bands F#0 and #1 of RU#1 can be assigned to the second CU / DU200 of MNO#0, and unit bands F#2 and #3 of RU#1 can be assigned to the second CU / DU200 of MNO#1. Then, unit bands F#2 and #3 of RU#2 can be assigned to the first CU / DU200 of MNO#0, and unit bands F#0 and #1 of RU#2 can be assigned to the first CU / DU200 of MNO#1. Furthermore, the unit bands F#2 and #3 of RU#3 can be allocated to the second CU / DU 200 of MNO#0, and the unit bands F#0 and #1 of RU#3 can be allocated to the second CU / DU 200 of MNO#1.

[0043] In this way, the initial use bandwidth is determined so that the bandwidth usage upper limit of each shared RU 20 is not exceeded and the output amount from each MNO's CU / DU 200 does not exceed a predetermined threshold. In Fig. 7(b), the same number of unit bandwidths are allocated to MNOs #0 and #1 in each shared RU 20, but as shown in Fig. 7(c), the number of unit bandwidths allocated to MNOs #0 and #1 in each shared RU 20 may be different. The initial use bandwidth shown in Fig. 7(c) does not exceed the bandwidth usage upper limit of each shared RU 20 and does not exceed the output amount from each MNO's CU / DU 200.

[0044] The initial use band for each shared RU 20 and each MNO CU / DU 200 is expressed by the matrix O initSpecifically, for example, as shown in FIG. 8, the initial usage band can be expressed by a usage band matrix O consisting of rows corresponding to the shared RU 20 and columns corresponding to the unit bands available for use by each MNO. In the usage band matrix O shown in FIG. 8, elements corresponding to the bands used by each MNO in each shared RU 20 are indicated by "1", and elements corresponding to bands not used by each MNO are indicated by "0". As described above, when an initial usage band that does not exceed the band usage upper limit is appropriately determined, the matrix O corresponding to this initial usage band is init is set.

[0045] Then, the optimal weight for each unit band for each UE 30 when the initial use band is used is calculated. That is, the optimal weight matrix W init is calculated (step S202). Here, a metric U that is an index of the fairness of the allocation of bandwidth to each MNO and the throughput can be defined by, for example, the following formula (1).

number

[0046] This metric U is an index of the fairness of bandwidth allocation and system throughput, and can be called the Proportional Fairness (PF) utility. MNO is the total number of MNOs, N UE is the total number of UE30, N F is the total number of unit bandwidths in each shared RU 20, N RU indicates the total number of shared RU20. m,t,f,u are elements of the optimal weight matrix W corresponding to MNO#m, RU#t, unit band F#f, and UE#u, and indicate the weight of the corresponding unit band F#f for UE#u. m,t,f,u is a predicted communication rate for MNO#m, RU#t, unit band F#f, and UE#u, and can be calculated by the following formula (2). rm,t,f,u =B m,t,f ·log 2 (1+γ m,t,f,u ) ···(2)

[0047] However, in formula (2), B m,t,f is the bandwidth of MNO#m, RU#t, and unit band F#f, and is a preset value. m,t,f,u is a predicted received SINR (Signal to Interference Noise Ratio) corresponding to MNO#m, RU#t, unit band F#f, and UE#u, and indicates the received SINR in UE#u of the corresponding unit band F#f. m,t,f,u can be calculated by the following formula (3) using the reception quality collected by the reception quality collecting unit 121.

number

[0048] In formula (3), p tx indicates the transmission power of each shared RU 20, and O m,t,f are elements of the band-usage matrix O corresponding to MNO#m, RU#t, and unit band F#f, and indicate whether the corresponding unit band F#f is used or not. m,t,u is a channel gain in MNO#m, RU#t, and UE#u, and indicates a value corresponding to the reception quality such as RSRP. 2 indicates noise such as thermal noise.

[0049] The optimal weight matrix W that maximizes the metric U in equation (1) above init is calculated by using the Karush-Kuhn-Tucker condition (KKT) under the condition that the sum of the weights of all UEs 30 in the unit band F#f used is 1. m,t,f,u It can be calculated by calculating w m,t,f,u can be calculated by the following formula (4).

number

[0050] However, in formula (4), μ m,t,f denotes an undetermined Lagrange multiplier that corresponds to the condition that the sum of the weights of all UEs 30 in the unit band F#f used is 1. Also, T' m,t,f,u is the total throughput of UE#u excluding the throughput of MNO#m, RU#t, and unit bandwidth F#f. m,t,f,u As described above, indicates the predicted communication rate in MNO#m, RU#t, unit band F#f, and UE#u.

[0051] The optimal weight matrix W calculated in this way init is calculated for each MNO, and indicates the optimal weight for each unit band for each UE 30 when the initial use band is used. Specifically, as shown in Fig. 9, for example, the optimal weight matrix W consists of rows corresponding to UE 30 and columns corresponding to unit bands available for use by each shared RU 20. For unit bands corresponding to each column of the optimal weight matrix W, whether or not they are used for each MNO is determined by the use band matrix O, and the weights of all UEs 30 for unused unit bands (i.e., unit bands whose elements are 0 in the use band matrix O) are 0.

[0052] Then, the system throughput can be maximized by each UE 30 wirelessly communicating with the shared RU 20 using the unit band with the largest weight in the optimal weight matrix W. In Fig. 9, the maximum weights for UE #0, #3, #4, and #25 are indicated by diagonal lines. That is, the system throughput can be maximized by UE #0 wirelessly communicating with RU #10 using unit band F #0, UE #3 wirelessly communicating with RU #10 using unit band F #0, UE #4 wirelessly communicating with RU #0 using unit band F #0, and UE #25 wirelessly communicating with RU #0 using unit band F #0.

[0053] The optimal weight matrix W init Once calculated, the optimal weight matrix W initPF utility U according to init is calculated (step S203). That is, the optimal weight matrix W init The metric U in the above formula (1) is calculated from the above. Then, the variable U max , O opt , W opt The initial values ​​of the PF utility U init , the band matrix O init , the optimal weight matrix W init (Step S204). The subsequent process is repeated for each MNO, and the optimal bandwidth to be used in the shared RU 20 is determined for each MNO.

[0054] First, the current band matrix O opt A search pattern O that can be formed by exchanging the bands used by the same MNO between the shared RUs 20 from the bands used corresponding to can In other words, a search pattern O obtained by stopping use of one of a pair of shared RUs 20 for one unit band and starting use of the other, and starting use of another unit band by one of the same pair of shared RUs 20 and stopping use of the other is identified (step S205). can This search pattern O can Then, the total amount of bandwidth used by each shared RU 20 is the current bandwidth matrix O opt Since the search pattern does not change from the pattern of the bandwidth used corresponding to the search pattern O, the bandwidth usage upper limit of each shared RU 20 is not exceeded. can The process of specifying the number of the pixels will be described in detail later.

[0055] Search Pattern O can Once identified, each search pattern O can The following process is repeated for

[0056] That is, the temporary band usage matrix O temp As a search pattern O can is set (step S206), and this used band matrix O tempThe optimal weight matrix W under temp is calculated by the above formula (4) (step S207). Then, the optimal weight matrix W temp Once calculated, the optimal weight matrix W temp PF utility U according to temp is calculated by the above formula (1) (step S208). The PF utility U temp is the search pattern O can It is the largest PF utility under.

[0057] Therefore, search pattern O can PF Utility U temp The current PF utility U max In other words, the used band is compared with the search pattern O. can It is determined whether the metric can be increased by changing the PF utility U temp The current PF utility U max If it is equal to or less than this (step S209 No), can The determination regarding the other search patterns O can The process from step S206 is repeated for

[0058] On the other hand, PF Utility U temp The current PF utility U max If it is greater than (Yes in step S209), the variable U max , O opt , W opt Each of them is a PF utility U corresponding to the search pattern Ocan. temp , the band matrix O temp , the optimal weight matrix W temp (Step S210). Then, the PF utility U max Search pattern O that makes can If even one is found, other search patterns O canThen, it is determined whether or not a sequential update mode is set in which the determination regarding the above is omitted (step S211).

[0059] If the sequential update mode is not set (step S211 No), the PF utility U max Search pattern O to increase can To check for the presence of other search patterns, can The process from step S206 is repeated for all search patterns O can When the processing of steps S206 to S211 is completed, the processing of steps S206 to S211 is repeated, and the used band matrix O opt It is then determined whether or not the value has been changed (step S212).

[0060] On the other hand, if the sequential update mode is set (Yes in step S211), the PF utility U max , the band matrix O opt , the optimal weight matrix W opt Since the update of the search pattern O can In the repetition of the processes in steps S206 to S211, the determination regarding the used band matrix O opt It is then determined whether or not the value has been changed (step S212).

[0061] In the determination of step S212, the used band matrix O opt If it is determined that the matrix has been changed (Yes in step S212), the new band matrix O opt Further PF utility U based on max Increase the bandwidth matrix O opt Therefore, the process of step S205 is executed again to obtain a new usable band matrix O opt Search pattern based on O can The above-mentioned processes in steps S206 to S211 are repeated for each of the

[0062] In contrast, in the determination of step S212, the used band matrix O optIf it is determined that the matrix O has not been changed (step S212 No), opt PF utility U according to max Since it is determined that the maximum opt The bandwidth used by each shared RU 20 is determined according to the bandwidth used matrix O opt The unit bands whose elements are "1" in are determined as the bands to be used by each shared RU 20. opt In step S213, the UEs 30 that are to be connected to the shared RU 20 using the respective bands are determined according to the optimal weight matrix W opt The unit band with the largest weight is determined as the connection destination of each UE 30.

[0063] The above steps S205 to S213 are repeated for each MNO, thereby determining the band in use for each MNO in each shared RU 20, and determining the UEs 30 that will use each band in use to wirelessly communicate with the shared RU 20. These bands in use are bands that maximize the PF utility, and can ensure fairness in the allocation of bands to each MNO while maximizing system throughput.

[0064] Next, the search pattern O in step S205 described above is can The identification process will be described below with reference to a flow chart shown in FIG. 10, giving a specific example.

[0065] First, the band matrix O base is the current band matrix O opt (Step S301). Then, the used band matrix O base In step S302, a first unit bandwidth that is a used bandwidth in any one of the shared RUs 20 and is not a used bandwidth in any other shared RU 20 is selected, along with a pair of shared RUs 20 that satisfy this condition.

[0066] Specifically, the band matrix O base For example, as shown in FIG. 11(a), the used band matrix O has rows corresponding to shared RUs 20 and columns corresponding to unit bands available for use by each MNO, with elements corresponding to unit bands that are in use being "1" and elements corresponding to unit bands that are not in use being "0". base In this case, if the element in the t-th row from the top and the f-th column from the left is expressed as (t,f), then the band matrix O base In the region corresponding to MNO#0, a pair of RU#t1 and RU#t2 where (t1, f1) is "1" and (t2, f1) is "0" and a first unit band F#f1 are selected. In the example shown in Fig. 11(a), for example, unit band F#0 of the pair of RU#0 and RU#2 satisfies the condition.

[0067] When a combination of a pair of shared RUs 20 and a first unit band is selected, it is determined whether or not there is a second unit band in the unit bands in the pair of shared RUs 20, the second unit band being used in the opposite manner to the first unit band (step S303). base It is determined whether there is a second unit band F#f2 in which (t1, f2) is "0" and (t2, f2) is "1" in the region corresponding to MNO#0.

[0068] As a result of this determination, if a second unit band F#f2 that satisfies the condition exists (Yes in step S303), the first and second unit bands of the pair of selected shared RUs 20 are switched in use and search pattern O is created. can (Step S304). That is, the used band matrix O base The elements of (t1,f1) are changed from "1" to "0", the elements of (t2,f1) are changed from "0" to "1", the elements of (t1,f2) are changed from "0" to "1", and the elements of (t2,f2) are changed from "1" to "0", resulting in a used band matrix O can is obtained.

[0069] Specifically, for example, as shown in FIG. 11(a) and (b), the use / non-use of the first unit band F#0 of the pair of RU#0 and RU#2 is switched, and the use / non-use of the second unit band F#2 is also switched. As a result, the use band matrix O base From the above, the search pattern O shown in FIG. can This will be obtained.

[0070] In this way, one search pattern O can If the second unit band F#f2 is identified, or if the second unit band F#f2 does not exist in the determination in step S303 (step S303 No), it is determined whether the presence or absence of the second unit band has been determined for all combinations of the pair of shared RUs 20 and the first unit band (step S305). If the presence or absence of the second unit band has been determined for all combinations (step S305 Yes), the search pattern O can On the other hand, if there is a combination for which the presence or absence of the second unit bandwidth has not yet been determined (No in step S305), another combination of the pair of shared RUs 20 and the first unit bandwidth is selected again in step S302.

[0071] In this way, the current band matrix O opt In this case, the bands used by the same MNO are switched between the shared RUs 20 to obtain search pattern O. can By identifying each one, the current band matrix O opt That is, it is possible to identify all patterns of the bands in use in which the use of a set of unit bands is switched. Then, all the identified search patterns O can In the current band matrix O opt Similarly, the bandwidth usage limit is not exceeded. can As mentioned above, the current PF utility U max The band matrix O used to make larger opt is searched for, and the bandwidth used in the shared RU 20 is optimized.

[0072] As described above, according to the present embodiment, the usable band allocated to each MNO in the shared RU is set so as not to exceed a predetermined band usage upper limit, and the allocation of the usable band to each MNO is optimized so as to maximize a predetermined metric based on the reception quality of the UE. Therefore, even if each MNO uses the usable band allocated to it, the capacity of the FH line is not exceeded, and the system throughput can be maximized. In other words, the expansion of the system capacity can be promoted, and the throughput can be improved.

[0073] (Embodiment 2) In the above-mentioned embodiment 1, a search pattern for searching an optimal band matrix is ​​specified by replacing bands used by the same MNO, but it is also possible to replace bands used across MNOs. Therefore, in embodiment 2, a process for specifying a search pattern by replacing bands used across MNOs will be described.

[0074] The configuration of the wireless communication system, the configuration of the communication control device, and the configuration of the CU / DU according to the second embodiment are the same as those of the first embodiment (FIGS. 1 to 3), and therefore the description thereof will be omitted. In the second embodiment, the band optimization method in the band optimization unit 123 of the communication control device 100 is different from that in the first embodiment.

[0075] Figures 12 and 13 are flow diagrams showing a bandwidth optimization method according to embodiment 2. In Figures 12 and 13, the same parts as in Figures 5 and 6 are given the same reference numerals, and detailed explanations thereof will be omitted.

[0076] First, an initial use band is set for each shared RU 20 in accordance with the band use upper limit notified by the FH band setting unit 122 (step S201), and an optimal weight matrix W corresponding to the initial use band is calculated. init and PF Utility U init is calculated (steps S202 and S203). Then, a variable U max , O opt , W opt The initial values ​​of the PF utility U init, the band matrix O init , the optimal weight matrix W init (step S204).

[0077] Once the initial values ​​of each variable are set, the current band matrix O opt A search pattern O that can be formed by exchanging the bands used between the shared RUs 20 from the bands used corresponding to can is identified (step S401). Here, unlike in the first embodiment, switching of the bands in use across MNOs is permitted. That is, for a unit band available to one MNO, one of a pair of shared RUs 20 stops using it and the other starts using it, and for a unit band available to another MNO, one of the pair of shared RUs 20 starts using it and the other stops using it, thereby obtaining search pattern O. can This search pattern O may be specified. can Then, the total amount of bandwidth used by each shared RU 20 is the current bandwidth matrix O opt Since the search pattern does not change from the pattern of the bandwidth used corresponding to the search pattern O, the bandwidth usage upper limit of each shared RU 20 is not exceeded. can The process of specifying the number of the pixels will be described in detail later.

[0078] Search Pattern O can Once identified, each search pattern O can The following process is repeated for

[0079] That is, the temporary band usage matrix O temp As a search pattern O can is set (step S206), and this used band matrix O temp The optimal weight matrix W under temp and PF Utility U temp is calculated (steps S207 and S208). Then, the PF utility U temp The current PF utility U max It is determined whether the PF utility U is greater than temp The current PF utility Umax If it is equal to or less than the above (No in step S209), other search patterns O can The process from step S206 is repeated for

[0080] On the other hand, PF Utility U temp The current PF utility U max If it is greater than (Yes in step S209), the variable U max , O opt , W opt Each of them is a PF utility U corresponding to the search pattern Ocan. temp , the band matrix O temp , the optimal weight matrix W temp Then, it is determined whether the sequential update mode is set (step S211). If the sequential update mode is not set (step S211 No), another search pattern O is updated. can The process from step S206 is repeated for all search patterns O can When the processing of steps S206 to S211 is completed, the processing of steps S206 to S211 is repeated, and the used band matrix O opt It is then determined whether or not the value has been changed (step S212).

[0081] Also, if the sequential update mode is set (step S211 Yes), the PF utility U max , the band matrix O opt , the optimal weight matrix W opt Since the update of the search pattern O can In the repetition of the processes in steps S206 to S211, the determination regarding the used band matrix O opt It is then determined whether or not the value has been changed (step S212).

[0082] In the determination of step S212, the used band matrix O opt If it is determined that the used band matrix O has been changed (Yes in step S212), the process of step S401 is executed again, and a new used band matrix O optSearch pattern based on O can The above-described processing of steps S206 to S211 is repeated for the used band matrix O opt If it is determined that the matrix O has not been changed (step S212 No), opt The bandwidth used by each shared RU 20 is determined according to the optimal weight matrix W opt According to the above, the UEs 30 that will connect to the shared RU 20 using the respective available bands are determined (step S213).

[0083] In this embodiment, the search pattern O is set by allowing the switching of the bands used across MNOs. can is specified, the band in use for each MNO in each shared RU 20 is determined, and the UE 30 that will wirelessly communicate with the shared RU 20 using each band in use is determined, without repeating the above process for each MNO. These bands in use are bands that maximize the PF utility, and it is possible to ensure fairness in the allocation of bands to each MNO and maximize the system throughput.

[0084] Next, the search pattern O in step S401 described above is can The identification process will be described with a specific example with reference to the flow chart shown in Fig. 14. In Fig. 14, the same parts as in Fig. 10 are given the same reference numerals, and detailed description thereof will be omitted.

[0085] First, the band matrix O base is the current band matrix O opt (Step S301). Then, the used band matrix O base In step S501, a first unit bandwidth that is a bandwidth used by a first MNO in any shared RU 20 and is not a bandwidth used by the same first MNO in any other shared RU 20 is selected, and a pair of shared RUs 20 that satisfy this condition is selected.

[0086] Specifically, the band matrix O base For example, as shown in FIG. 15(a), the used band matrix O has rows corresponding to shared RUs 20 and columns corresponding to unit bands available for use by each MNO, with elements corresponding to unit bands that are in use being "1" and elements corresponding to unit bands that are not in use being "0". base In this case, if the element in the fth column from the left for the mth MNO in the tth row from the top is expressed as (m,t,f), then the band usage matrix O base A pair of RU#t1 and RU#t2 in which (m1, t1, f1) is "1" and (m1, t2, f1) is "0" and a first unit band F#f1 in the first MNO#m1 are selected. In the example shown in Fig. 15(a), for example, unit band F#1 in MNO#0 for the pair of RU#1 and RU#2 satisfies the condition.

[0087] When a combination of a pair of shared RUs 20, a first MNO, and a first unit band is selected, it is determined whether or not a second unit band in a second MNO, which is in use in the opposite manner to the first unit band in the first MNO, is included in the unit bands in the pair of shared RUs 20 (step S502). base It is determined whether there is a second MNO#m2 and a second unit band F#f2 in which (m2, t1, f2) is "0" and (m2, t2, f2) is "1." Note that the second MNO#m2 does not necessarily have to be an MNO different from the first MNO#m1, and may be any MNO including the first MNO#m1.

[0088] As a result of this determination, if there are a second MNO#m2 and a second unit band F#f2 that satisfy the condition (Yes in step S502), the first unit band and the second unit band of the pair of the selected shared RU 20 are switched in use or not, and search pattern O is generated. can (Step S503). That is, the used band matrix O baseThe elements of (m1, t1, f1) are changed from "1" to "0", the elements of (m1, t2, f1) are changed from "0" to "1", the elements of (m2, t1, f2) are changed from "0" to "1", and the elements of (m2, t2, f2) are changed from "1" to "0", resulting in a used band matrix O can is obtained.

[0089] Specifically, for example, as shown in Fig. 15(a) and (b), the use of the first unit band F#1 in the first MNO#0 of the pair of RU#1 and RU#2 is switched, and the use of the second unit band F#2 in the second MNO#1 is switched. As a result, the use band matrix O base From the above, the search pattern O shown in FIG. can This will be obtained.

[0090] In this way, one search pattern O can If the second MNO#m2 and the second unit band F#f2 are identified, or if it is determined in step S502 that the second MNO#m2 and the second unit band F#f2 do not exist (step S502 No), it is determined whether the presence or absence of the second MNO and the second unit band has been determined for all combinations of the pair of shared RUs 20, the first MNO, and the first unit band (step S305). If it has been determined for all combinations (step S305 Yes), the search pattern O is can On the other hand, if there is a combination for which the presence or absence of the second MNO and the second unit band has not yet been determined (No in step S305), another combination of the pair of shared RU 20, the first MNO, and the first unit band is selected again in step S501.

[0091] In this way, the current band matrix O opt In the above, the bands used by each MNO are switched between the shared RUs 20 to obtain the search pattern O. can By identifying each one, the current band matrix O optThat is, it is possible to identify all patterns of the bands in use in which the use of a set of unit bands is switched. Then, all the identified search patterns O can In the current band matrix O opt Similarly, the bandwidth usage limit is not exceeded. can As mentioned above, the current PF utility U max The band matrix O used to make larger opt is searched for, and the bandwidth used in the shared RU 20 is optimized.

[0092] As described above, according to the present embodiment, the usable band allocated to each MNO in the shared RU is set so as not to exceed a predetermined band usage upper limit, and the allocation of the usable band to each MNO is optimized so as to maximize a predetermined metric based on the reception quality of the UE. Therefore, even if each MNO uses the usable band allocated to it, the capacity of the FH line is not exceeded, and the system throughput can be maximized. In other words, the expansion of the system capacity can be promoted, and the throughput can be improved. [Explanation of symbols]

[0093] 110, 210 input / output section 120, 220 processor 121 Reception quality collection unit 122 FH band setting section 123 Bandwidth Optimization Unit 124 Allocation information generation unit 130, 230 Memory 221 UE information acquisition unit 222 Notification information generation unit 223 Scheduling Department 240 FH Transmitter / Receiver

Claims

1. A communication control device that allocates to a plurality of operators bands of a plurality of radio devices connected to a plurality of baseband devices managed by the plurality of operators and shared by the plurality of operators, the communication control device comprising: an allocating unit that allocates a bandwidth for each of the wireless devices to the plurality of operators in accordance with a bandwidth usage upper limit set for each of the wireless devices such that a usage bandwidth used by the plurality of operators does not exceed the bandwidth usage upper limit; an output unit that outputs allocation information indicating bands allocated to the plurality of operators by the allocation unit to each of the plurality of baseband devices; A communication control device comprising:

2. The allocation unit, Optimizing the allocation of bandwidth for each of the wireless devices so as to maximize a metric that is an index of throughput corresponding to the bandwidth allocation to the plurality of operators.

2. The communication control device according to claim 1.

3. The allocation unit, A metric for changing the bandwidth allocation for each of the wireless devices is calculated using reception quality information in a terminal device that wirelessly communicates with the wireless device, and a bandwidth allocation for each of the wireless devices that maximizes the calculated metric is obtained.

3. The communication control device according to claim 2.

4. The allocation unit, A bandwidth allocation for each of the wireless devices corresponding to a maximum metric when the bandwidth allocation is changed within the operator is obtained.

4. The communication control device according to claim 3.

5. The allocation unit, A bandwidth allocation for each of the wireless devices corresponding to a maximum metric when the bandwidth allocation is changed across the multiple operators is obtained.

4. The communication control device according to claim 3.

6. The allocation unit, A terminal device that will wirelessly communicate with the wireless device using the bands allocated to the plurality of operators is determined.

3. The communication control device according to claim 2.

7. A communication control method for allocating bands of a plurality of radio devices to a plurality of operators, the bands being connected to a plurality of baseband devices managed by the plurality of operators and shared by the plurality of operators, the plurality of operators comprising: assigning a bandwidth for each of the wireless devices to the plurality of operators in accordance with a bandwidth usage upper limit set for each of the wireless devices such that a bandwidth used by the plurality of operators does not exceed the bandwidth usage upper limit; Outputting allocation information indicating bands allocated to the plurality of operators to each of the plurality of baseband devices.

23. A communication control method comprising the steps of:

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